A
`
`TEXT-BOOK OF CHEMISTRY
`
`INTENDED FOR THE USE OF PHARMA-
`
`CEUTICAL AND MEDICAL STUDENTS
`
`BY
`
`SAMUEL P. SADTLER , PH.D. , LL.D.
`
`MEMBER OF COMMITTEE ON REVISION OF THE UNITED STATES PHARMACOPOEIA; PROFESSOR
`
`EMERITUS OF CHEMISTRY IN THE PHILADELPHIA COLLEGE OF PHARMACY ; AUTHOR
`99
`OF "A HAND- BOOK OF CHEMICAL EXPERIMENTATION ,'
`
`A HAND- BOOK OF
`
`INDUSTRIAL ORGANIC CHEMISTRY ," AND CHEMICAL EDITOR
`66
`99
`
`OF
`
`THE UNITED STATES DISPENSATORY.
`
`VIRGIL COBLENTZ , PH.D. , F.C.S.
`
`MEMBER OF COMMITTEE ON REVISION OF THE UNITED STATES PHARMACOPOEIA ; PROFESSOR
`
`EMERITUS OF CHEMISTRY AND PHYSICS IN THE DEPARTMENT OF PHARMACY
`66
`
`VOLUMETRIC ANALYSIS "
`
`OF COLUMBIA UNIVERSITY ; AUTHOR OF
`66
`
`AND
`
`THE NEWER REMEDIES ."
`
`AND
`
`JEANNOT HOSTMANN , PH . G.
`
`ASSOCIATE PROFESSOR OF CHEMISTRY AND DIRECTOR OF THE ANALYTICAL LABORATORY IN
`
`THE DEPARTMENT OF PHARMACY OF COLUMBIA UNIVERSITY .
`
`FIFTH EDITION REVISED AND REWRITTEN
`
`T
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`I
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`O
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`R
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`D
`
`E
`T
`
`A
`V
`A
`N
`T
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`PHILADELPHIA & LONDON
`
`J. B. LIPPINCOTT COMPANY
`
`Petitioner Dr. Squatch
` Ex. 1050
`
`

`

`36152A
`
`JM
`
`DAN
`
`GE AND
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`DA
`
`18.1
`
`L
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`Copyright , 1894 , by SAMUEL P. SADTLER AND HENRY TRIMBLE.
`
`Copyright , 1898 , by SAMUEL P. SADTLER AND HENRY TRIMBLE .
`
`Copyright , 1900 , by SAMUEL P. SADTLER AND VIRGIL COBLENTZ .
`
`Copyright, 1906 , by SAMUEL P. SADTLER AND VIRGIL COBLENTZ .
`
`Copyright, 1918, by SAMUEL P. SADTLER AND VIRGIL COBLENTZ
`
`All Rights Reserved .
`
`Authority to use for comment the Pharmacopœia of the United States of America,
`
`Eighth and Ninth Decennial Revisions , in this volume , has been granted by the Board of
`
`Trustees of the United States Pharmacopœial Convention , which Board of Trustees is in
`
`no way responsible for the accuracy of any translation of the official weights and
`
`measures or for any statements as to strength of official preparations .
`
`ELECTROTYPED AND PRINTED BY J. B. LIPPINCOTT COMPANY , PHILADELPHIA, U. S. A.
`
`

`

`PREFACE TO FIFTH EDITION
`
`THE present edition of this pharmaceutical text -book has been in
`
`course of preparation for several years , having been begun before the
`
`appearance of the 9th Revision of the U. S. Pharmacopoeia .
`
`As is well known , chemical manufacturing has undergone quite im-
`
`portant changes in recent years , and in particular since the revolution in
`
`trade incident to the outbreak of the present great world war.
`
`The
`
`Editors have sought to bring the book abreast of this changed condition
`
`in the chemical world.
`
`The sections on Inorganic Chemistry have been therefore largely re-
`
`written and much that is new introduced , and older statements withdrawn
`
`in numerous sections .
`
`This part of the work has been attended to by Professor Coblentz ,
`
`who has been of recent years in close touch with the manufacturing side
`
`of chemistry, and Professor Jeannot Hostmann of the Department of
`
`Pharmacy of Columbia University , who is actively engaged in chemical
`
`laboratory work .
`
`The section on Elementary Physics has also been largely rewritten by
`
`Professor Hostmann .
`
`The section on Organic Chemistry has been brought up to date with
`
`the introduction of considerable new matter by Professor Sadtler , who
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`has also contributed the chapter on Electrolysis and its new applications .
`
`Some new and useful tables have , with the permission of the Trustees
`
`of the U. S. Pharmacopoeia , been inserted for the greater convenience of
`
`the pharmaceutical student and for convenient reference for pharmacists
`
`using the book.
`
`We believe that the book in its present form is adapted for use in the
`
`classes of our Pharmaceutical Schools as a text-book and at the same time
`
`is sufficiently complete in its scheme of treatment to make it valuable
`
`for the reference libraries of graduates and others who might turn to it
`
`as a reference book on chemistry and chemical products .
`
`SAMUEL P. SADTLER,
`
`VIRGIL COBLENTZ .
`
`iii
`
`September, 1918 .
`
`12/200738
`
`

`

`

`

`PREFACE TOTO THE FIRST EDITION .
`
`AN experience of some seventeen years as teachers in a professional
`
`school , where Chemistry is considered one of the foundation - stones upon
`
`which young men must build a technical education , has convinced the
`
`authors that the subject must be taught in a way that , while thoroughly
`
`scientific , is yet distinctly adapted to the ultimate uses of the students .
`
`The professions of Pharmacy and Medicine are closely related , and
`
`their uses for Chemistry are very much alike . The members of these
`
`professions must understand the composition and chemical properties
`
`and possibilities of the whole materia medica , both inorganic and organic ,
`
`in order safely to maintain the important trusts committed to them , -
`
`trusts involving the continued health and life of their fellow- men . The
`
`importance of thorough chemical knowledge for these related professions
`
`is now recognized in the fullest way in their official publication , the U. S.
`
`Pharmacopoeia , the last edition of which has embodied throughout the
`
`most detailed and exact statements of the chemical nature , properties ,
`
`and reactions of medicinal substances , together with methods of analysis
`
`or assay and tests for purity .
`
`We have sought in the following pages to offer a text - book on Chemistry
`
`which should combine scientific accuracy and completeness with that
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`special reference to the needs of the pharmaceutical and medical student ,
`
`as well as those in active professional practice , which will make it of value
`
`for both study and reference . Compounds recognized in the U. S. Phar-
`
`macopoeia are specially indicated , but they are not taken out of their
`
`proper position for such discussion .
`
`A brief outline of Elementary Physics , much of which is absolutely
`
`essential for the understanding of chemical methods , forms Part I.
`
`The convenient division of the elements into Non - Metals and Metals is
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`followed in the main in Parts II . and III . , subject to the limitations
`
`made necessary by the chemical relationship as indicated by the valence
`
`groups .
`
`Part IV . deals with Organic Chemistry . While the arrange-
`
`ment here followed is strictly scientific , it has been sought to give the
`
`subject a distinctly practical bearing , and to this end the industrial appli-
`
`cations of organic compounds have been noted , and in a number of cases
`
`illustrated .
`
`In Part V. a brief outline of Qualitative and Quantitative Analysis is
`
`given , the methods being such as have proved of value in our own prac-
`
`V
`
`

`

`vi
`
`PREFACE TO THE FIRST EDITION .
`
`tice . A number of the Pharmaceutical Assays of the U. S. Pharmacopoeia
`
`are also added .
`
`The Appendix contains , besides a list of the chemical elements with
`
`atomic weights and valences , thermometric scales and the specific gravity
`
`tables in most general use .
`
`The authors have made free use of many chemical works , such as
`
`Flückiger's " Pharmaceutische Chemie , " Schmidt's " Pharmaceutische
`
`Chemie , " Meyer and Jacobson's " Organische Chemie , "
`
`Bernthsen's
`
`" Organische Chemie , " Weyl's " Organische Chemie für Mediciner , "
`
`Fischer's " Neuere Arzneimittel , " Gamgee's " Physiological Chemistry , "
`
`Pictet's " Alcaloides Végétaux , " Power's " Essential Oils , " Allen's
`
`"Commercial Organic Analysis , " Prescott's " Organic Analysis , " and
`
`Sadtler's " Industrial Organic Chemistry . "
`
`Our thanks are due to J. C. Peacock for valuable assistance in the prep-
`
`aration of Parts III . and V. , to S. S. Sadtler and H. Blount Hunter for
`
`work on the index , and to Edwin Thorpe for the execution of many orig-
`
`inal drawings for the illustration of the work .
`
`S. P. S.
`
`H. T.
`
`PHILADELPHIA, February , 1895 .
`
`

`

`PAGE
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`I I 3 4 5 7
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`041
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`ΙΟ
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`4
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`17
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`18
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`19
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`268
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`82333
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`22
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`26
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`29
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`6603
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`3 6
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`6
`
`39
`
`39
`
`40
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`57
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`3300
`
`vii
`
`CONTENTS .
`
`PART I.
`
`ELEMENTARY PHYSICS
`
`CHAPTER I.
`
`MATTER , FORCE , AND MOTION.
`
`1. Introductory .
`
`2. General Properties .
`
`3. Volume and Mass .
`
`4. Units of Measure ..
`
`5. Motion and Force ..
`
`6. Forms of Attraction .
`
`7. Motion ....
`
`8. Machines ..
`
`CHAPTER II.
`
`SPECIAL PROPERTIES OF MATTER.
`
`(A) Special Properties of Solids ..
`
`(B) Special Properties of Liquids
`
`I. Attraction and Repulsion in Liquids ..
`
`2. Pressure of Liquids ....
`
`3. Pressure upon Bodies immersed in Liquids ...
`
`(C) General Properties of Gases
`
`1. Attraction and Repulsion in Gases….
`
`2. Atmospheric Pressure .
`
`3. Buoyancy of Gases .
`
`4. Apparatus based upon Atmospheric Pressure
`
`CHAPTER III .
`
`ACOUSTICS .
`
`I. Vibrations and Undulations ...
`
`2. General Properties of Sound .
`
`CHAPTER IV .
`
`RADIANT ENERGY .- I . HEAT .
`
`I. The Nature of Heat ..
`
`II. Sources of Heat ....
`
`III. Effects of Heat .
`
`IV . Transmission of Heat .
`
`

`

`PAGE
`
`59
`
`59
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`60
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`62
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`62
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`63
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`488
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`*8
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`69
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`77
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`80
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`83
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`88822
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`90
`
`91
`
`91
`
`92
`
`95
`
`96
`
`104
`
`108
`
`113-116
`
`116-117
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`118-119
`
`119-124
`
`124-132
`
`133
`
`133-139
`
`139-144
`
`144
`
`153
`
`viii
`
`CONTENTS
`
`CHAPTER V.
`
`MAGNETISM .
`
`I. Magnets , Natural and Artificial ..
`
`II. Properties of Magnets ...
`
`III. Laws of Magnetism ..
`
`IV . The Earth as a Magnet .
`
`V. Applications of Magnetism .
`
`CHAPTER VI .
`
`ELECTRICITY .
`
`(A ) Static or Frictional Electricity .
`
`( B ) Dynamic Electricity ……….
`
`Electro- Magnetics ..
`
`Applications of Electro - Magnetism ..
`
`Voltaic Induction ...
`
`CHAPTER VII .
`
`Magneto-Electric and Dynamo- Electric Generators .
`
`Change of Electrical Energy into Heat ..
`
`Change of Electrical Energy into Light ..
`
`Thermo- Electric Currents ....
`
`CHAPTER VIII.
`
`RADIANT ENERGY . - II . LIGHT.
`
`I. Nature of Light ..
`
`II. Reflection of Light
`
`III. Refraction of Light ..
`
`IV . Optical Instruments Based upon the Use of Lenses .
`
`V. Double Refraction and Polarization ...
`
`PART II .
`
`CHEMISTRY OF THE NON -METALS.
`
`CHAPTER I.
`
`THEORETICAL INTRODUCTION .
`
`Matter, Changes, Mixtures , Compounds ...
`
`Elements , Names, Symbols , Atomic Weights .
`
`Chemical Formulæ and Equations ....
`
`Valency , Variations , Compound Radicles ...
`
`Compound Molecules, Binary and Ternary Compounds, Acids , Bases,
`
`and Salts ..
`
`Oxidation and Reduction ...
`
`Conditions of Chemical Change .
`
`Electro - Chemistry , Electrolytic Dissociation ..
`
`Laws Governing Chemical Change .
`
`Stochiometry .. . .
`
`

`

`CONTENTS
`
`ix
`
`CHAPTER II.
`
`HYDROGEN .
`
`History, Physical and Chemical Properties , and Uses ..
`
`CHAPTER III .
`
`THE HALOGENS .
`
`Chlorine ....
`
`Hydrogen and Chlorine ..
`
`Bromine ....
`
`Bromine and Hydrogen .
`
`Iodine ....
`
`Iodine and Hydrogen .
`
`Fluorine ..
`
`Fluorine and Hydrogen ....
`
`Review of the Halogen Group ..
`
`CHAPTER IV .
`
`THE OXYGEN Group.
`
`Oxygen
`
`Ozone .
`
`Oxygen and Hydrogen
`
`1. Water ..
`
`2. Hydrogen Dioxide ..
`
`Oxygen and Chlorine Compounds .
`
`Sulphur..
`
`Sulphur and Hydrogen Compounds .
`
`Sulphur and Oxygen Compounds
`
`1. Sulphur Dioxide and Sulphurous Acid ..
`
`2. Sulphur Trioxide and Sulphuric Acid ..
`
`Selenium ..
`
`Tellurium ..
`
`CHAPTER V.
`
`THE NITROGEN GROUP .
`
`Nitrogen ...
`
`The Atmosphere .
`
`The Argon Group ..
`
`Nitrogen and Hydrogen , Ammonia ..
`
`Nitrogen and Oxygen Compounds ..
`
`Phosphorus ......
`
`Phosphorus and Oxygen Compounds .
`
`Arsenic ..
`
`Antimony .
`
`PAGE
`
`160
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`166
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`169
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`173
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`175
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`179
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`182
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`186
`
`187
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`188
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`190
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`193
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`195
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`203
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`206
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`214
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`217
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`222
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`226
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`235
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`237
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`238
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`240
`
`243
`
`244
`
`250
`
`258
`
`263
`
`270
`
`279
`
`

`

`Boron and Compounds ...
`
`CONTENTS
`
`CHAPTER VI .
`
`BORON.
`
`CHAPTER VII .
`
`THE CARBON Group .
`
`Carbon ....
`
`Carbon and Hydrogen .
`
`Carbon and Oxygen ..
`
`Carbon and Sulphur .
`
`Silicon ...
`
`The Periodic System ..
`
`Potassium ..
`
`Sodium ..
`
`Ammonium .
`
`Lithium .
`
`Rubidium ..
`
`Cæsium ..
`
`Calcium ..
`
`Strontium .
`
`Barium .
`
`Magnesium ..
`
`Glucinum .
`
`Zinc ....
`
`Cadmium ..
`
`CHAPTER VIII .
`
`CLASSIFICATION OF THE Elements .
`
`PART III.
`
`CHEMISTRY OF THE METALS.
`
`CHAPTER I.
`
`THE ALKALI METALS .
`
`CHAPTER II.
`
`THE ALKALINE EARTH GROUP.
`
`CHAPTER III
`
`THE MAGNESIUM GROUP .
`
`PAGE
`
`286
`
`289
`
`294
`
`298
`
`307
`
`309
`
`315
`
`321
`
`338
`
`361
`
`367
`
`369
`
`370
`
`371
`
`384
`
`387
`
`392
`
`398
`
`399
`
`405
`
`

`

`CONTENTS
`
`xi
`
`CHAPTER IV..
`
`THE SILVER Group.
`
`PAGE
`
`407
`
`414
`
`Silver ....
`
`Gold ..
`
`Copper...
`
`Mercury...
`
`CHAPTER V.
`
`THE COPPER AND MERCURY GROUP .
`
`CHAPTER VI .
`
`ALUMINUM AND THE RARE Earths .
`
`418
`
`424
`
`437
`
`444
`
`447
`
`447
`
`451
`
`458
`
`459
`
`463
`
`465
`
`472
`
`477
`
`484
`
`493
`
`495
`
`Aluminum ....
`
`Rare Earths and Metals (Scandium , Yttrium , Lanthanum , Ytterbium, Cerium,
`
`Neodymium,
`
`Praseodymium ,
`
`Samarium,
`
`Erbium ,
`
`Terbium ,
`
`Gallium ,
`
`Indium, and Thallium) ...
`
`CHAPTER VII .
`
`THE TIN GROUP . -THE BISMUTH GROUP .
`
`Germanium .
`
`Tin ...
`
`Lead .
`
`Titanium, Zirconium , and Thorium .
`
`Bismuth .....
`
`Vanadium, Niobium, and Tantalum ..
`
`Chromium ..
`
`Radio-activity .
`
`Manganese ...
`
`Iron ...
`
`Nickel ..
`
`Cobalt .
`
`CHAPTER VIII .
`
`THE CHROMIUM GROUP.
`
`CHAPTER IX.
`
`THE IRON Group.
`
`CHAPTER X.
`
`THE PLATINUM GROUP.
`
`Platinum ...
`
`Rhodium , Ruthenium , Palladium , Iridium and Osmium ..
`
`497
`
`500-501
`
`

`

`xii
`
`CONTENTS
`
`PART IV .
`
`ORGANIC CHEMISTRY .
`
`CHAPTER I.
`
`INTRODUCTORY .
`
`CHAPTER II.
`
`OPEN -CHAIN OR ALIPHATIC HYDROCARBONS.
`
`I. The Saturated Hydrocarbons or Paraffin Series ....
`
`II. The Unsaturated Hydrocarbons of the Olefine Series ……..
`
`III. The Unsaturated Hydrocarbons of the Acetylene Series .
`
`IV. The Unsaturated Hydrocarbons of the Series CnH2n-4 and CnH2n−6 .
`
`CHAPTER III .
`
`DERIVATIVES OF THE OPEN-CHAIN HYDROCARBONS .
`
`I. Halogen Derivatives ....
`
`II. Alcohols or Hydroxides of the Hydrocarbon Radicles
`
`III . Ethers or Oxides of the Hydrocarbon Radicles .
`
`IV. Sulpho-Alcohols, Sulpho- Ethers , and Sulphonic Compounds
`
`V. Aldehydes and Ketones ...
`
`VI . Acids and Derivatives of Acids ..
`
`VII. Esters or Ethereal Salts ..
`
`Industries of the Fats ..
`
`VIII . Amines and Amides...
`
`IX . Carbohydrates .....
`
`Industries of the Sugars, Starch , and Cellulose .
`
`X. Fermentation and Fermentation Industries . .
`
`XI . Derivatives of Carbonic Acid ....
`
`XII . Cyanogen and its Derivatives ..
`
`CHAPTER IV .
`
`CLOSED-CHAIN GROUPS WITH LESS THAN SIX CARBON ATOMS .
`
`I. Isocyclic Compounds (Polymethylenes ) .
`
`II. Heterocyclic Compounds ....
`
`CHAPTER V.
`
`CLOSED-CHAIN OR AROMATIC COMPOUNDS.
`
`Isocyclic Hydrocarbons and Derivatives (Theory of) ....
`
`PAGE
`
`503
`
`521
`
`525
`
`527
`
`528
`
`529
`
`533
`
`543
`
`546
`
`548
`
`552
`
`569
`
`576
`
`579
`
`583
`
`592
`
`594
`
`602
`
`607
`
`612
`
`613
`
`616
`
`

`

`CONTENTS
`
`xiii
`
`CHAPTER VI.
`
`ISOCYCLIC COMPOUNDS CONTAINING ONE NUCLEUS.
`
`I. Hydrocarbons ....
`
`II . Halogen Derivatives of the Ben zene Hydrocarbons .
`
`III. Sulphonic Derivatives ..
`
`IV. Nitro Derivatives .
`
`V. Amido Derivatives of the Benzene Hydrocarbons .
`
`VI . Diazo and Azo Compounds .
`
`Hydrazines ..
`
`VII . Phenols and their Derivatives and Quinones .
`
`VIII. Aromatic Alcohols , Aldehydes , and Ketones .
`
`IX . Phenol Alcohols and Phenol Aldehydes .
`
`X. Aromatic Acids and Phenol Acids ...
`
`AROMATIC COMPOUNDS WITH MORE THAN ONE NUCLEUS.
`
`CHAPTER VII.
`
`I. Compounds with Uncondensed Nuclei.
`
`(Isocyclic Compounds ) .
`
`PAGE
`
`622
`
`626
`
`628
`
`629
`
`630
`
`635
`
`637
`
`645
`
`648
`
`650
`
`660
`
`II. Compounds with Two Condensed Benzene Nuclei .
`
`(Isocyclic Compounds) 664
`
`III. Compounds with Three Condensed Nuclei .
`
`(Isocyclic Compounds ) ....... 667
`
`IV. Compounds containing Nitrogen in the Benzene Nucleus.
`
`(Heterocyclic
`
`Compounds) ....
`
`V. Six-membered Cyclic Compounds Containing Oxygen .
`
`(Heterocyclic
`
`Compounds )...
`
`CHAPTER VIII .
`
`THE ALKALOIDS AND PTOMAINES ..
`
`CHAPTER IX .
`
`THE TERPENES AND THEIR DERIVATIVES .
`
`I. The Terpenes .
`
`II. The Camphors .
`
`III. The Essential Oils .
`
`IV . The Resins ...
`
`GLUCOSIDES -BITTER AND NEUTRAL PRINCIPLES .
`
`CHAPTER X.
`
`I. The Glucosides ....
`
`II. Bitter Principles and Neutral Bodies ..
`
`TISSUE- FORMING SUBSTANCES , OR PROTEID MATTER .
`
`CHAPTER XI .
`
`Chemical Reactions of the Proteids ..
`
`Classification of Proteid Compounds .
`
`CHAPTER XII .
`
`ELECTROLYSIS AND ITS APPLICATIONS .
`
`Conditions , Table of Electro-Chemical Equivalents, Electro - Chemical Analysis,
`
`Electrotyping, Electroplating , Electric Refining of Metals ..
`
`671
`
`677
`
`678
`
`695
`
`699
`
`702
`
`705
`
`709
`
`713
`
`716
`
`718
`
`725
`
`728
`
`732
`
`733
`
`Processes involving Electrolysis ....
`
`Processes involving the Electric Furnace .
`
`Electrolysis Applied to Organic Compounds .
`
`APPENDIX
`
`Reference Tables ...
`
`INDEX .
`
`737-751
`
`753
`
`

`

`CHAPTER III
`
`THE MAGNESIUM GROUP
`
`MAGNESIUM
`
`Symbol, Mg.
`
`Atomic Weight, 24.32.
`
`Valence , II.
`
`History.
`
`-
`
`Attention was first directed to the magnesium salts about
`
`the close of the seventeenth century by Grew , a physician of London .
`
`He found a peculiar salt in the mineral spring at Epsom, which salt
`
`soon became celebrated for its medicinal virtues .
`
`The metal was
`
`first isolated by Davy , in 1808 , although he did not obtain it in a
`
`pure condition . Bussy was the first to obtain a tangible quantity of the
`
`metal , which he accomplished by fusing the chloride with potassium .
`
`Occurrence .-The metal is not found in the uncombined state in
`
`nature .
`
`Its compounds , however, are almost as widely distributed as
`
`those of calcium, although not in such large quantities . The principal
`
`minerals containing it are magnesite, MgCO3 ; dolomite , MgCa ( CO3 ) 2 ;
`
`kieserite, MgSO..H₂O ; carnallite, a chloride of magnesium and potas-
`
`sium, KCl , MgCl2.6H₂O ; and the following silicates : talc, 3MgO.4SiO2.-
`
`H₂O ; meerschaum , 2MgO.3SiO2.2H , O ; and serpentine asbestos , 3MgO.-
`
`2SiO2.2H₂O . Magnesium salts are found in plants , in which they may to a
`
`certain extent replace the salts of calcium . As phosphate, magnesium is
`
`found in the bones and urine of animals .
`
`Isolation.- Magnesium is now usually prepared by the electrolysis of
`
`the fused double chloride ; that is, carnallite
`
`(MgCl,.KCI ) to which some
`
`fluorspar or sodium chloride is added as a flux. The vessel in which the
`
`decomposition is effected is made of especially prepared cast - steel , which
`
`acts as the negative pole at which the magnesium is liberated ; the positive
`
`pole is made of gas- carbon . In order to prevent the oxidation of the metal ,
`
`a stream of hydrogen or nitrogen is led through the vessel during the operation .
`
`The metal may also be prepared by the reduction of fused magnesium
`
`chloride with sodium or aluminum .
`
`The metal is furnished usually either in form of powder ( " flash -powder ")
`
`or ribbon .
`
`Magnesium unites directly with nitrogen at 670 ° to magnesium nitride.
`
`Properties .-Magnesium is a silver- white , highly lustrous metal,
`
`having a specific gravity of 1.75 .
`
`It is unchangeable in dry air, but in
`
`the presence of moisture it gradually becomes covered with a film of
`
`oxide . When heated without access of air, magnesium melts at about
`
`650 ° and boils at 1120 ° . Heated in the air it ignites, and burns with
`
`a blinding white light which is especially rich in actinic rays . Water
`
`is decomposed by magnesium but slightly at or above 100 ° , with evolution.
`
`of hydrogen and the formation of magnesium oxide .
`
`Uses . On account of the comparatively low ignition-point ( 800 ° ) ,
`
`high heat of combustion ( 134,000 cal . ) , and relatively low heat of vapor-
`
`392
`
`

`

`MAGNESIUM AND THE HALOGENS .
`
`393
`
`ization of magnesium and the actinic activity of the magnesium light ,
`
`it is useful in photography , and enters into the composition of the
`
`numerous " flash- light " powders and illuminants employed for mili-
`
`tary purposes .
`
`Previous to the development of electric lighting it
`
`was used in making strong lights for signalling purposes .
`
`It is used
`
`in pyrotechny . Bengal fires are made as follows : Red- 1 part of pul-
`
`verized shellac , 5 parts of dried strontium nitrate , 2.5 parts of powdered
`
`magnesium . Green-1 part of pulverized shellac , 6 parts of dried barium
`
`nitrate, 2.5 parts of powdered magnesium . An alloy of magnesium ( 10
`
`per cent. ) with aluminum is known as " magnalium " and is of a silver-
`
`white appearance, very light, fuses at 633 ° , and is used in aviation
`
`machines. Magnesium also has some use in the laboratory , where , on
`
`account of its freedom from arsenic , it may replace zinc in Marsh's
`
`test . In metallurgy magnesium is employed for scavenging alloys ; that
`
`is, for removing oxides of other metals, as aluminum , nickel , copper, brass ,
`
`bronze , etc. Magnesium reduces many metallic oxides to their metals ,
`
`as boric oxide , silica , etc.
`
`MAGNESIUM AND THE HALOGENS
`
`Magnesium Chloride, MgCl2.6H₂O .- Sea water and most mineral
`
`waters contain magnesium chloride .
`
`In the solid state it is found
`
`abundantly as carnallite , KC1 , MgCl „ .6H₂O , at Stassfurt ; also in a
`
`number of the double salts in that locality .
`
`It may be prepared by
`
`dissolving magnesite in hydrochloric acid ; but , since it is a by- product
`
`of not much value in the preparation of potassium chloride from carnal-
`
`lite, it is usually derived from this source.
`
`Properties .- Magnesium chloride occurs in colorless , very deli-
`
`quescent, monoclinic crystals .
`
`It cannot be deprived of its water
`
`of crystallization by heat , since , when heated ,
`
`it decomposes with
`
`evolution of hydrochloric acid and formation of magnesium oxy-
`
`chloride , MgCl.OH. This decomposition may be prevented by adding 3
`
`parts of ammonium chloride for every part of magnesia . A double salt,
`
`MgCl2.2NHCl , forms , which may be evaporated to dryness without
`
`decomposition.
`
`The anhydrous salt is obtained by heating the double chloride ,
`
`MgCl₂.NH, C1.6H₂O , until a crystalline mass , which fuses at 708 ° , forms ;
`
`this distills at red heat ; or it may be prepared by drying the crystallized
`
`chloride in a stream of hydrochloric acid gas .
`
`Anhydrous magnesium chloride occurs in transparent , laminated ,
`
`pearly plates , which dissolve in water with the evolution of heat .
`
`It
`
`possesses a bitter, saline taste , and is readily soluble in water. With
`
`magnesium oxide it forms an oxychloride which is insoluble in water .
`
`Water containing magnesium chloride cannot be used in boilers owing
`
`to its liberation of hydrochloric acid which attacks the iron .
`
`Uses .-Magnesium chloride is used in the preparation of a cement
`
`

`

`394
`
`CHEMISTRY OF THE METALS.
`
`prepared by mixing magnesium oxide and chloride with infusorial
`
`earth or sawdust and sufficient water to form a paste.
`
`It is also used as a
`
`finisher for cotton and woolen textiles .
`
`Magnesium Ammonium Chloride, MgCl2.NH.C1.6H₂O , is a double salt which
`
`is usually prepared by evaporating a solution of 3 parts of ammonium chloride
`
`with one part of magnesium chloride . The addition of ammonia water does not
`
`precipitate the magnesium.
`
`Magnesium Oxychloride .-When an aqueous solution of magnesium chloride
`
`of 1.16 to 1.26 specific gravity is mixed with freshly - prepared magnesium oxide ,
`
`the mass after some time hardens sufficiently to be capable of taking a high polish. It
`
`has a composition represented by the formula MgCl2 ( OH ) 2.4H , O. On exposure
`
`to the air for some time it absorbs carbon dioxide . Another oxychloride is
`
`formed when magnesium sulphate, containing ammonium hydroxide and chlo-
`
`ride, is exposed to the air for some time : the crystalline precipitate, which is
`
`deposited, has the composition Mg, Cl ( OH ) ¸.4H ,O .
`
`Magnesium Bromide , MgBr,.6H ,O, occurs in sea water and in a number of
`
`salt springs.
`
`It is this salt more than any other that is the source of bromine.
`
`It may be prepared by heating magnesium in bromine vapor or dissolving
`
`freshly precipitated magnesium hydroxide in hydrobromic acid and evaporating
`
`over sulphuric acid .
`
`The anhydrous salt forms in solid , white , crystalline masses , which are
`
`very deliquescent, and become hot in contact with water. When the salt
`
`contains water of crystallization , it loses hydrobromic acid on the applica-
`
`tion of heat, leaving a residue of magnesium oxybromide .
`
`Magnesium Iodide , MgI ,.8H₂O, occurs associated with the bromide in sea
`
`water. It may be prepared by adding iodine to an excess of magnesium powder
`
`suspended in water, digesting, filtering, and evaporating over sulphuric acid. It forms
`
`very deliquescent, hydrated crystals, which readily decompose with liberation
`
`of iodine.
`
`Magnesium Nitride , Mg, N₂ - Obtained as a yellow powder when magnesium
`
`is heated in an atmosphere of nitrogen or a current of ammonia :
`
`Mg, + 2NH ,
`
`=
`
`Mg, N , + 3H2.
`
`When magnesium is heated in a current of air at 670 ° , a mixture of oxide and
`
`nitride forms .
`
`When the nitride is boiled with water, ammonia is given off :
`
`Mg, N₂ + 3H₂O = 2NH , + 3MgO .
`
`When heated in a current of CO , cyanogen is obtained :
`
`MgN₂ + 3CO = 3MgO + 2CN + C.
`
`MAGNESIUM AND OXYGEN
`
`Magnesium Oxide, MgO . Magnesii Oxidum , U.S.P.-Black , in 1755 ,
`
`appears to have been the first to prepare this oxide . He noted its
`
`solubility in diluted sulphuric acid , which served to distinguish it from
`
`lime .
`
`Occurrence .- Magnesium oxide is found native in the rare mineral
`
`periclase, found near Naples .
`
`Preparation .-Magnesia is prepared on a large scale by heating the car-
`
`bonate, ( MgCO3 ) , Mg ( OH ) 2.5H₂O = 5MgO + 6H₂O + 4CO2. When the light
`
`carbonate is ignited , the light or calcined magnesia, magnesia usta , results . When
`
`a denser carbonate is used , the result is heavy magnesia , Magnesii Oxidum Pon-
`
`derosum , U.S.P.
`
`The operation is conducted in iron or earthenware crucibles ; at 300 ° to
`
`350° the decomposition readily takes place, and it is known to be complete
`
`when a small quantity , taken from the middle of the vessel with an iron spoon,
`
`cooled and mixed with water , gives no effervescence with dilute hydrochloric acid.
`
`

`

`SALTS OF MAGNESIUM .
`
`395
`
`Probably the most important feature in the successful manufacture of
`
`this compound is that of avoiding too high a temperature . In order to pre-
`vent parts of the powder from becoming too hot it should be stirred fre-
`
`quently, or it has been recommended to perform the ignition in shallow pans ,
`so that the depth of the carbonate does not exceed 2 to 3 inches . Much
`
`also depends upon the purity and physical condition of the carbonate em-
`ployed.
`
`Properties .-Official " light " or " heavy " magnesia , which after igni-
`
`tion contains not less than 96 per cent . of MgO and not more than 2 per
`
`cent. of CaO, occurs as a loose , white , odorless powder ; possessing
`
`an earthy but not saline taste .
`
`It is almost insoluble in water ( I to
`
`55,000 ) , insoluble in alcohol , but readily soluble in dilute acids without
`
`effervescence . Being a weak base , magnesium readily forms insoluble
`
`basic ( oxy ) salts with acids . When mixed with water magnesium oxide
`
`forms the hydroxide Mg ( OH ) 2 .
`
`The presence of ammonium salts materially increases its solubility
`
`in water. In moist air it readily absorbs moisture and carbon dioxide ,
`
`becoming converted into a basic carbonate .
`
`Magnesia is not visibly affected by any temperature below that of
`
`the oxyhydrogen flame , but it will, at lower temperatures , become
`
`more dense and crystalline . When heated with distilled water it does
`
`not yield more than 2 per cent . of soluble salts ( U.S.P. ) . The heavy mag-
`
`nesia is a denser and finer powder , but in most other characters resem-
`
`bles the light compound.
`
`Magnesium Hydroxide , Mg ( OH ) 2, occurs in nature as the mineral brucite.
`
`It may be prepared by allowing magnesium oxide which has not been over-
`
`calcined to stand in contact with water, or more quickly by heating the same com-
`
`pound with water to 150 ° .
`
`Sodium or potassium hydroxide precipitates mag-
`
`nesium hydroxide from solutions of the salts .
`
`Magnesium hydroxide is a white , nearly insoluble powder.
`
`It is easily
`
`soluble in solutions of ammonium salts . Magnesium salts are not precipi-
`
`tated by the reagents for the heavy metals, as ammonium hydroxide or hydro-
`
`sulphide , when ammonium salts as NH , C1 are present due to the formation of
`
`complex magnesium ammonium compounds . At 100 ° magnesium hydroxide is not
`
`affected, but when the temperature approaches redness it is easily converted into
`
`oxide .
`
`It is sufficiently soluble in water to impart an alkaline reaction .
`
`Magma Magnesiæ, U. S. P. Milk of Magnesia .-A suspension of magne-
`
`sium hydroxide in water , obtained by interaction between magnesium carbonate , 125
`
`gm., and a solution of sodium hydroxide , 80 gm . This mixture yields not less than
`
`6.5 per cent. nor more than 7.5 per cent . of Mg ( OH ) ,.
`
`SALTS OF MAGNESIUM
`
`Magnesium Sulphite , MgSO ,.6H₂O , may be made by adding sulphurous acid
`
`in excess to a mixture of 8 parts of magnesium oxide in 16 parts of water .
`
`Properties .- Magnesium sulphite is a white, crystalline powder , becoming
`
`oxidized on exposure to air, odorless , having a slightly bitter, somewhat sul-
`
`phurous taste , and a neutral or slightly alkaline reaction .
`
`It is soluble in
`
`20 parts of water at 15 ° , and in 19 parts of boiling water ; insoluble in alcohol .
`When heated to 200°
`the salt loses its water of crystallization , amounting
`
`to 50.9 per cent . , and is converted into magnesia and anhydrous magnesium
`
`sulphate .
`
`Magnesium Sulphate , MgSO , .7H,O . Magnesii Sulphas , U.S.P.-
`
`Epsom salt became known about the end of the seventeenth century,
`
`

`

`396
`
`CHEMISTRY
`
`OF THE METALS .
`
`because of its valuable purgative qualities , and was designated on the
`
`continent of Europe as bitter salt and Sal Anglicum .
`
`Occurrence . - Magnesium sulphate occurs in many mineral waters ,
`
`the most notable being those of Pullna and Seidlitz , in Bohemia , of
`
`Epsom , in England , of Friedrichshall , in Germany , and Hunyadi Janos ,
`
`in Hungary . Under the name of kieserite , MgSO.H₂O , magnesium sul-
`
`phate is found at Stassfurt. The upper layer of this salt deposit , known
`
`as Abraumsalz, is a mixture of magnesium and potassium salts , chiefly
`
`carnallite , kainite , and kieserite .
`
`Preparation.
`
`Formerly much magnesium sulphate was obtained by
`
`the concentration of natural bitter waters . At the present time large
`
`quantities are obtained as a by- product in the manufacture of carbon.
`
`dioxide for use in mineral waters . Magnesite is used to furnish this
`
`gas, and sulphuric acid is used to effect its liberation , as follows :
`
`MgCO , + H₂SO , = MgSO . + CO , + H , O .
`Carbon
`Dioxide .
`
`Magnesite .
`
`Sulphuric
`Acid.
`
`Magnesium
`Sulphate.
`
`Water..
`
`After the escape of carbon dioxide , the residue is dissolved in hot
`
`water, neutralized with magnesite , some ammonium sulphide added , and
`
`the mixture allowed to stand for some time in order to separate iron ;
`
`finally , the clear liquid is concentrated and allowed to crystallize .
`
`The Abraumsalz is also employed as a source of magnesium sulphate . This
`
`salt is usually suspended in baskets over open evaporators , so that it is
`
`brought in contact with the ascending steam ; by this means the very
`
`soluble magnesium and potassium chlorides are dissolved , while the kieser-
`
`ite remains behind . Kieserite is not easily dissolved by water , but on con-
`
`tact with steam it disintegrates and is converted into Epsom salt, containing
`
`7 molecules of water ; in this form it is dissolved and recrystallized .
`
`Properties .-Magnesium sulphate, " which contains not less than 48.59
`
`nor more than 53.45 per cent . of the anhydrous salt , " crystallizes from
`
`water in colorless , rhombic prisms , or in small acicular crystals ; the latter
`
`form is obtained by allowing the crystallization to take place from hot con-
`
`centrated solutions . The salt is without odor , and has a cooling, saline ,
`
`bitter taste ; the crystals slowly effloresce in dry air.
`
`It is soluble in
`
`I part of water at 25 ° , and in 0.2 part of boiling water ; insoluble in
`
`alcohol . When heated to 52 ° the salt loses I molecule of water ; from
`
`this temperature up to 132 ° it loses 5 additional molecules , and at some-
`
`what above 200 ° the remaining seventh molecule of water is removed.
`
`and the salt becomes anhydrous . The aqueous solution is neutral to litmus.
`
`One molecule of water of crystallization ( above 200 ° ) of MgSO , .H₂O.-
`
`6H₂O is readily replaced by sulphates of the alkali metals , yielding double
`
`isomorphous salts of the general formula MgSO , .MeSO4.6H₂O , as MgSO ..-
`
`K₂SO4.6H₂O ; MgSO4 ( NH4 ) 2SO4.6H2O , etc. This may be extended to
`
`such other isomorphous sulphates as NiSO , .7H₂O , COSO , 7H , O , and
`
`ZnSO , .7H₂O , which form similar double salts with the alkali sulphates.
`
`

`

`SALTS OF MAGNESIUM .
`
`397
`
`When anhydrous magnesium sulphate is dissolved in hot concentrated
`
`sulphuric acid, six - sided tabular crystals separate on cooling, which have
`
`the composition MgSO4.H₂SO ..
`
`Uses .- Magnesium sulphate is used in medicine as an active cathartic .
`
`It also has some use in dyeing and calico printing as a finisher. When
`
`this salt is used with aniline colors , the finished goods are found to with-
`
`stand the action of soap .
`
`Magnesium Nitrate , Mg ( NO ) 2.6H , O, is prepared by neutralizing nitric acid
`
`with magnesium carbonate.
`
`It forms deliquescent monoclinic prisms or acicular
`
`crystals. From hot solutions it sep