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WORKS OF Prof. E. A. RUDDIMAN 
 
 PUBLISHED BY 
 
 JOHN WILEY & SONS. 
 
 Incompatibilities in Prescriptions. 
 
 For Students in Pharmacy and Medicine, and 
 Practising Pharmacists and Physicians. Third 
 Edition, Partly Rewritten. 8vo, vi + 312 pages. 
 Cloth, $2.00. 
 
 Whys in Pharmacy. 
 
 A Compilation of Reasons Underlying the Princi- 
 ples of Pharmacy, Supplemented by a Table of 
 Equations, izmo, vi + 196 pages. Cloth, $1.00 
 
WHYS IN PHARMACY 
 
 A COMPILATION OF REASONS UNDERLYING THE 
 
 PRINCIPLES OF PHARMACY, SUPPLEMENTED 
 
 BY A TABLE OF EQUATIONS 
 
 BY 
 
 EDSEL A. RUDDIMAN, Ph.M., M.D. 
 
 Professor of Pharmacy and Materia Medica in Vanderbilt University 
 Author of ""Incompatibilities in Prescriptions" 
 
 FIRST EDITION 
 
 THIRD THOUSAND. 
 
 NEW YORK 
 
 JOHNWILEY^ & SONS 
 
 London: CHAPMAN & HALL, Limited 
 
 1911 
 
t^^ 
 
 Copyright, 1906 
 
 BY 
 
 EDSEL A. RUDDIMAN 
 
 THE SCIENTIFIC PRESS 
 
 ROBERT DRUMMONO AND COMPANr 
 
 BROOKLYN, N. Y. 
 
PREFACE. 
 
 In the publication of these questions and answers 
 the writer claims no originality. The only reason he 
 has for putting them into book form is because he 
 has had numerous requests for them from his students 
 and the readers of the Bulletin of Pharmacy in which 
 much of the matter has been printed. 
 
 Early in the course of the author's teaching he came 
 to the conclusion that the teaching of the reasons for 
 the use of certain ingredients and for mixing these 
 in certain orders is one of the most important parts 
 of the work — more essential than the memorizing of 
 formulas. The book is not intended as a quiz com- 
 pend, but as an aid to those who wish to get at the 
 principles underlying the subject. At first only the 
 questions were written, leaving the student to look 
 up the answers for himself. Mr. Joseph Helfman, 
 editor of the Bulletin of Pharmacy, suggested that 
 
 111 
 
 265648 
 
IV PREFACE. 
 
 more good would be. done the readers by giving the 
 answers as well, and the writer came to the same 
 conclusion. 
 
 Acknowledgment is made of the free use of Cas- 
 pari's Treatise on Pharmacy and other books on 
 pharmacy and chemistry. 
 
 Edsel a. Ruddiman. 
 
 Nashville, October, 1905. 
 
CONTENTS. 
 
 PAGE 
 
 PREPARATIONS 1 
 
 Waters 2 
 
 Cerates 5 
 
 Papers q 
 
 Collodions 7 
 
 Decoctions 8 
 
 Elixirs 8 
 
 Plasters 11 
 
 Emulsions 12 
 
 Percolation and Fluid Extracts 14 
 
 Solid Extracts 22 
 
 Glycerites 25 
 
 Infusions 26 
 
 Liniments 27 
 
 Solutions 29 
 
 Masses 38 
 
 Mixtures 40 
 
 Mucilages 41 
 
 Oleates 42 
 
 Oleoresins 43 
 
 Oils 44 
 
 Pills 50 
 
 Powders 54 
 
 Resins 59 
 
 Spirits 59 
 
 Suppositories 62 
 
 Syrups 63 
 
 Tinctures. 70 
 
 Troches 77 
 
 Ointments 77 
 
 Wines 82 
 
 V 
 
VI CONTENTS. 
 
 PAGE 
 
 CHEMICALS 83 
 
 Acids 83 
 
 Inorganic Compounds 92 
 
 Aluminum Salts 92 
 
 Ammonium Salts 93 
 
 Antimony Salts 93 
 
 Silver Salts 94 
 
 Gold Salts 94 
 
 Bismuth Salts 94 
 
 Calcium Salts 95 
 
 Chromium Salts 96 
 
 Iron Salts 97 
 
 Mercury Salts 102 
 
 Magnesium Salts 107 
 
 Lead Salts 108 
 
 Potassium Salts 109 
 
 Sodium Salts 113 
 
 Sulphur 115 
 
 Zinc Salts 115 
 
 ORGANIC DRUGS 117 
 
 ALKALOIDS. DRUG ASSAYS 126 
 
 PRESCRIPTIONS 138 
 
 MISCELLANEOUS 160 
 
 EQUATIONS 165 
 
* J K 9 
 
 WHYS IN PHARMACY- 
 
 PREPARATIONS. 
 
 WATERS. 
 
 Why is purified talc used in making many official 
 waters? Because it breaks the volatile substances 
 into minute particles, thereby increasing the surface 
 exposed to the solvent action of the water; and it 
 also removes the excess of the volatile substances, 
 making a clear solution. At the same time, talc is 
 not appreciably soluble in water. 
 
 Why is calcium phosphate of the 1890 method 
 objectionable? It is slightly soluble, particularly in 
 the presence of acid substances, and many waters 
 made with it seem to be good media for the growth 
 of micro-organisms. 
 
 Why is magnesium carbonate an objectionable 
 substitute for purified talc? The commercial article 
 contains some hydrate which is somewhat soluble in 
 water, making a solution that is sufficiently alkaline 
 to cause the formation of a precipitate when any one 
 
^ V/HYS ipj" PHARMACY. 
 
 of a number of metallic or alkaloidal salts is added 
 to the water. Moreover, magnesium carbonate com- 
 bines with acids that are normally present in some 
 of the oils, forming soluble compounds which may 
 give colored preparations. 
 
 Why is the 1880 method of using cotton objection- 
 able? Because it does not divide the oil into such 
 fine globules, it takes more time, more oil is wasted, 
 and sometimes oil globules are washed into the 
 filtrate. 
 
 Why is a jug better than a bottle in making flavor- 
 ing waters by mixing oil with hot water? The rough 
 surface of the jug helps to break up the oil. 
 
 Why are waters made by distillation frequently 
 of finer flavor than when made by solution of oil? 
 Acids and ethers present in some plants pass over 
 with the oil and modify the odor. 
 
 Why is the addition of alcohol as a preservative 
 objectionable? A small amount helps rather than 
 hinders decomposition, while a large amoimt is 
 objectionable on account of its therapeutic action. 
 
 Why is a plug of cotton put into the neck of the 
 stock-bottle when a distilled or flavoring water is re- 
 moved by siphoning? As the water is drawn off 
 air enters the bottle and must pass through the cotton 
 which filters out dust and germs, protecting the water 
 from the growth of microscopic organisms. 
 
 Why is it objectionable to use water that has not 
 been distilled for making preparations or filling pre- 
 scriptions? Ordinary water ma}^ contain ammonia, 
 
PREPARATIONS. 3 
 
 carbon dioxide, inorganic salts, organic matter, and 
 bacteria. 
 
 Why is the hardness of water called '' temporary 
 hardness" when it is due to calcium carbonate in 
 solution? The calcium carbonate is held in solu- 
 tion by carbon dioxide and boiling drives this off 
 and precipitates the salt, making the water soft. 
 
 Why does the U. S. P. direct that the first 100 cc. 
 of distillate be thrown away in making distilled 
 water? Because it holds in solution practically all 
 of the gases that were held in solution in the 1000 cc. 
 before distillation. 
 
 Why are the last 100 cc. left in the retort in making 
 distilled water? If distillation were carried too far 
 some inorganic matter might be carried over me- 
 chanically, or some of the organic matter decom- 
 posed and volatilized, or injury might result to the 
 retort. 
 
 Why should the container for distilled water be 
 rinsed with hot distilled water just before being filled? 
 To wash out impurities and destroy all germs. 
 
 Why is condensed steam from boiler-pipes an ob- 
 jectionable substitute for distilled water? It is 
 generally contaminated with oil from the boiler and 
 iron from the pipes. 
 
 Why is ammonia water sometimes marked '^FFF" 
 or ^^FFFF"? This refers to "the strength, but the 
 samples marked the same vary considerably. ^^F" 
 stands for fortis, strong, ^'FFF" for triple strength. 
 
 Why should stronger ammonia water be kept in 
 
4 WHYS IN PHARMACY. 
 
 "partially" filled bottles? The gas is readily given 
 up by the water and the pressure might easily be- 
 come so great as to burst the bottle. 
 
 Why is talc not used in making bitter almond 
 water? Oil of bitter almonds is sufficiently soluble 
 in water so that a clear solution results when the 
 desired amount of oil is used. 
 
 Why is natural oil sometimes preferable to the 
 artificial oil of bitter almonds? The artificial oil 
 does not contain hydrocyanic acid^ which is the seda- 
 tive principle. 
 
 Why should stronger orange flower water be kept 
 in loosely-stoppered bottles? If kept tightly stop- 
 pered it acquires a disagreeable foreign odor^ which 
 may be dissipated by exposure to air. 
 
 Why is alcohol used in making camphor water? 
 To dissolve the camphor so that it can be more 
 thoroughly distributed through the talc. 
 
 Why is the greater part of the alcohol allowed to 
 evaporate spontaneously? If the alcohol were not 
 evaporated the water would be more than saturated. 
 If heat were used to evaporate it some camphor 
 would be volatilized. 
 
 Why should manganese dioxide not be too fine or 
 hydrochloric acid too concentrated in making chlo- 
 rine water (1890)? In either case the generation of 
 gas at first would be too fast. 
 
 Why should chlorine water be kept in a cool, 
 dark place? Heat volatihzes the chlorine and light 
 changes it, forming hydrochloric acid. 
 
i?REPARATIONS. 5 
 
 Why should an excess of chloroform be kept in 
 the container of chloroform water? So as to keep 
 a saturated solution at all times, chloroform being 
 very volatile. 
 
 Why should chloroform water be kept in an am- 
 ber-colored bottle? Light decomposes it, forming 
 hydrochloric acid. 
 
 Why is barium dioxide hydrated and kept cold in 
 making hydrogen dioxide water (1890)? Cold aids 
 hydration and hydration causes a larger yield. 
 
 Why is phosphoric acid used in preference to other 
 acids in making hydrogen dioxide water? Experi- 
 ence shows that phosphoric acid gives a rather larger 
 yield. 
 
 Why is a small amount of acid left in hydrogen 
 dioxide water? The acid tends to prevent decom- 
 position of hydrogen dioxide. 
 
 Why should hydrogen dioxide water be kept in 
 loosely stoppered containers? Because it slowly de- 
 composes, hberating oxygen, and sufficient pres- 
 sure may be produced to burst the bottle. Keeping 
 the bottle tightly stoppered does not seem to retard 
 decomposition, but keeping in the dark does. 
 
 CERATES. 
 
 AVhy in making cerates is it best to melt the ingre- 
 dient having the highest melting-point first and 
 then the one having the next highest melting-point? 
 If they are all heated together the one having the 
 
6 WHYS IN PHARMACY. 
 
 lowest melting-point may be decomposed by the 
 temperature necessary to melt the one having the 
 highest melting-point. 
 
 Why are the melted ingredients stirred constantly 
 until cold in making simple cerate? To prevent 
 separation^ wax sohdifying first would tend to 
 separate. 
 
 Why is Hquid petrolatum used in making cerate 
 of cantharides? By macerating cantharides with 
 liquid petrolatum the cantharidin is more com- 
 pletely dissolved by the base. This preparation 
 does not now have the odor of turpentine as did 
 that of the 1890 edition. 
 
 Why is wool-fat used in making cerate of lead 
 subacetate? It aids the mixing of the aqueous 
 solution. 
 
 Why are paraffin^ petrolatum, and camphor used 
 in place of camphor cerate in making cerate of lead 
 subacetate? Made with these the cerate keeps 
 better. The cerate made by the 1890 formula soon 
 turns yellow and rancid. 
 
 Why does the U. S. P. direct that resin cerate be 
 cooled mth occasional stirring? Continuous stirring 
 incorporates some air and is not necessary as the 
 cerate cools to a homogeneous mass without it. 
 
 PAPERS. 
 
 Why is the fixed oil removed from mustard in 
 making mustard paper? The fixed oil is inert and 
 makes the paper greasy and unsightly. 
 
PREPARATIONS. 7 
 
 Why should mustard paper be dipped into warm 
 water just before applying? Water is necessary to 
 allow the ferment to act on the sinigrin, forming 
 the volatile oil of mustard. Water also softens the 
 paper. Hot water must not be used because it 
 destroys the activity of the ferment and prevents 
 the formation of the volatile oil. 
 
 COLLODIONS. 
 
 Why should the neck of a collodion bottle be 
 thoroughly wiped out after pouring out some of the 
 collodion? If the stopper is inserted without this 
 wiping it is hkely to get fixed in so tightly that it 
 is necessary to break the bottle the next time collodion 
 is wanted. 
 
 Why is alcohol used in making collodion? Ether 
 alone does not dissolve guncotton as readily as 
 when it contains a little alcohol. 
 
 Why is cantharides exhausted with chloroform 
 instead of with collodion in making cantharidal 
 collodion? Chloroform leaves a residue which makes 
 a nearly clear solution with collodion. Collodion is 
 so tliick that it cannot be readily separated from 
 the insoluble part of the flies if it were used as the 
 macerating fluid. Ether is probably as good as 
 chloroform. 
 
 Why is plain collodion better than flexible collo- 
 dion for putting on small cuts? Plain collodion con- 
 tracts more than the flexible and draws the lips of 
 the wound together more. 
 
8 WHYS IN PHARM,\CY. 
 
 DECOCTIONS. 
 
 Why should decoctions not be made by dilution 
 of fluid extracts? Water does not dissolve the 
 same principles that are generally in solution in 
 the fluid extract, and consequently the therapeutic 
 action is not the same. 
 
 Why in making decoctions are drugs put into 
 cold water instead of hot water as in infusions? 
 Drugs suitable for decoctions more often contain 
 albuminous matter, which if coagulated at first by 
 hot water would make the extraction of the active 
 principles more difficult. 
 
 Why should hard or prolonged boiling be avoided? 
 The active principle may be decomposed or the 
 decoction loaded with tannin and inert matter. 
 
 Why should decoctions be strained at 40" C. rather 
 than strained when cold? Hot water sometimes 
 takes out active matter that is precipitated from 
 cold water. By straining when warm this is left 
 in and can be mixed with the liquid. 
 
 Why, in making decoction of cetraria (1890), is 
 cetraria macerated in cold water which is subse- 
 quently thrown away? Cold water takes out the 
 bitter principle, making the decoction more palatable. 
 
 ELIXIRS. 
 
 Why is purified talc used in making aromatic 
 ehxir? Because the oils in compound spirit of 
 orange are precipitated by the water and syrup, 
 
PREPARATIONS. 9 
 
 and an insoluble powder is necessary to remove the 
 excess. 
 
 Why should the filter be wetted with a mixture 
 contaimng at least twenty-five per cent, alcohol 
 instead of wetted with water in filtering aromatic or 
 other eUxirs? Water generally gives a turbid filtrate, 
 due to separation of small globules of oil. 
 
 Why do some elixirs give a turbidity with a small 
 amount of water but a clear solution with a large 
 amount? Aromatic elixir is a saturated solution 
 of oils which are thrown out of solution by a small 
 amount of water but redissolved by a larger amount. 
 
 Why is carmin generally not a good coloring- 
 agent for ehxirs? Elixirs are frequently acid and 
 acids precipitate carmin. 
 
 Why are ammonia water and acetic acid used in 
 making elixir of iron, quinine, and strychnine phos- 
 phates? To make ammonium acetate which tends 
 to prevent the precipitation of the iron phosphate. 
 
 Why do eUxirs containing the soluble phosphate 
 of iron with quinine sulphate so often precipitate? 
 Frequently the quinine sulphate is slightly acid, or 
 an acid is added to aid the solution of the quinine, 
 and acid precipitates the insoluble phosphate of iron. 
 
 Why is potassium citrate used in making elixir of 
 sahcyUc acid, N. F.? Potassium citrate aids the 
 solution of salicylic acid, possibly forming potassium 
 salicylate and citric acid. 
 
 Why is ammonia water used in elixir of ammonium 
 valerate, N. F.? Ammorium valerate, on exposure. 
 
10 WHYS IN PHARMACY, 
 
 slowly loses ammonia, liberating the insoluble liquid 
 valeric acid; ammonia combines with this. 
 
 Why is anethol preferred to oil of anise in elixir of 
 anise, N. F.? It has a finer odor and flavor. 
 
 Why is ammonia water used in elixir of bismuth, 
 N. F. ? Because the bismuth and ammonium citrate 
 loses ammonia, leaving the insoluble bismuth citrate, 
 and ammonia combines with it to form a soluble 
 compound. 
 
 Why is magnesium carbonate used in elixir of 
 buchu, N. F.? On adding the elixir and syrup to 
 the fluid extract of buchu resinous matter is pre- 
 cipitated; magnesium carbonate aids the removal 
 of this. 
 
 Why is elixir of cinchona, N. F., allowed to stand 
 as long as possible before filtering? So as to let the 
 fine precipitate which is formed settle as it tends to 
 clog the filter. 
 
 Why are citric acid and ammonia water used in 
 making elixir of cinchona, iron, and calcium lacto- 
 phosphate, N. F.? The ammonium citrate formed 
 prevents the precipitation of iron that might other- 
 wise take place. 
 
 Why is talcum used in preference to calcium phos- 
 phate in making compound digestive elixir, N. F.? 
 Calcium phosphate would dissolve in the hydro- 
 chloric and lactic acids, while purified talcum does 
 not. 
 
 Why is powdered pumice-stone used in making 
 aromatic elixir of yerba santa, N. F.? Some kind of 
 
PREPARATIONS. 11 
 
 insoluble powder must be used to aid the removal 
 of the precipitated resinous matter from the fluid 
 extract, and it is thought by some that the use of 
 pumice-stone gives a finer flavor to the finished 
 product than does calcium phosphate, possibly by 
 clearing the mixture without removing so much of 
 the flavoring principle. 
 
 Why are ammonia water and solution of tersulphate 
 of iron used in making elixir of gentian, N. F.? 
 Ammonia converts the ferric sulphate into the in- 
 soluble ferric hydrate, and this combines with tannin 
 in the compound spirit of cardamom to form an in- 
 soluble tannate of iron which may be removed by 
 filtration; the elixir can then be dispensed with 
 iron salts. 
 
 Why is the elixir of pepsin and bismuth, N. F., of 
 doubtful therapeutic value? Because in getting the 
 bismuth and ammonium citrate into solution a slight 
 excess of ammonia is used, making the solution a 
 little alkahne; and pepsin is said to be rendered en- 
 tirely inert by alkaUes. 
 
 PLASTERS. 
 
 Why is a plaster made with a rubber base supposed 
 to be less effective than one made with the lead- 
 plaster base? It is claimed that a rubber-base 
 plaster does not give up the medicinal matter as 
 readily as one made with lead plaster. 
 
 Why should spread plasters have a quarter to 
 
12 WHYS IN PHARMACY. 
 
 a half inch of leather or cloth not covered by the mass? 
 The plaster mass often softens with the heat of the 
 body and may ooze out, soiling and sticking to the 
 clothing. 
 
 Why are perforated plasters preferred to those not 
 perforated? They are more pHable, and they allow 
 the escape of exhalations of the skin, thus being 
 more comfortable. 
 
 Why are oleate of mercury and hydrous wool-fat 
 used in mercurial plaster? To aid the division of 
 metallic mercury used in the plaster. 
 
 Why is the reverse side of court plaster (1890) 
 coated with tincture of benzoin? To make it im- 
 pervious to air and water. 
 
 Why is glycerin used in making court plaster 
 (1890) ? It makes the gelatin more flexible and pre- 
 vents its cracking. 
 
 Why is water used in making lead plaster (1890)? 
 It enters into chemical reaction and tends to prevent 
 the burning of the organic matter. 
 
 Why is lead plaster washed with hot water? To 
 soften the plaster so that the sodium acetate may be 
 more easily washed out. 
 
 EMULSIONS. 
 
 Why must the mortar be perfectly dry, and the oil 
 free from moisture, when emulsions are made by 
 putting the oil and acacia into the mortar and then 
 adding the water? Because the presence of even a 
 
PREPARATIONS. 13 
 
 small amount of water forms a mucilage with some 
 acacia before it is mixed well with the oil, and thus 
 " cracks " the emulsion 
 
 Why do emulsions of volatile oils separate more 
 quickly than those of fixed oils? As a rule the emul- 
 sion is thinner. 
 
 Why are emulsions of the volatile oils and light 
 H quids best made in a bottle while emulsions of fixed 
 oils are made in a mortar? The ingredients in an 
 emulsion of a fixed oil make so tliick a hquid that 
 they cannot be quickly and well mixed. The emul- 
 sion of a volatile liquid is generally so thin that it can 
 be readily mixed by agitation. 
 
 Why are glass or porcelain mortars not so good 
 for making emulsions as Wedgewood? They are too 
 smooth. 
 
 Why are powdered gum-resins not as good for 
 making emulsions as the tears or masses? Frequently 
 considerable volatile matter is driven off in the drying 
 which is necessary before powdering. 
 
 Why is it not necessary to add an emulsifying 
 agent in making many seed and gum-resin emul- 
 sions? Because gummy matter is already present in 
 the drugs. 
 
 Why is an emulsion made with acacia whiter than 
 one made with most other emulsifying agents? Be- 
 cause acacia has the property of dividing oil into 
 smaller globules, and the smaller the globules the 
 whiter the emulsion. 
 
 Why should pressure with the pestle not be used 
 
14 WHYS IN PHARMACY. 
 
 in making emulsions in the mortar? Because pres- 
 sure generates heat, and heat tends to prevent emul- 
 sification. 
 
 Why is tragacanth sometimes used in connection 
 with acacia in emulsions? Acacia is a good emulsi- 
 fying agent, while tragacanth is useful to keep the 
 emulsified oil from separating from the aqueous 
 portion after the product is made. 
 
 Why is tincture of quillaja objectionable as an 
 emulsifying agent? It has some physiological action 
 of its own. 
 
 Why should strongly alcoholic fluids be diluted 
 with water before being mixed with emulsions? 
 Acacia, being insoluble in alcohol, is thrown out of 
 solution, and the emulsion is thus broken. 
 
 Why is expressed oil of almonds used in making 
 emulsion of chloroform? Because it is a fixed oil, 
 and fixed oils help to emulsify chloroform and keep 
 it in suspension. 
 
 Why, in making emulsion of cod liver oil with 
 hypophosphites, are the syrup and solution of hypo- 
 phospites added to the primary enmlsion instead 
 of being used in making the primary emulsion? 
 Sugar and salts tend to prevent emulsification. 
 
 PERCOLATION AND FLUID EXTRACTS. 
 
 Why was the term fluidextractum coined and used 
 in the U. S. P.? In order to separate the fluid from 
 the solid extracts. 
 
PREPARATIONS. 15 
 
 Why is a slightly conical percolator better than a 
 cylindrical one? Because when a drug swells after 
 being put into the percolator, it has a chance to 
 press upward, and therefore does not become so 
 firmly packed. 
 
 Why is a percolator only slightly conical better 
 than one more decidedly so? In a conical per- 
 colator the menstruum which passes through the 
 drug near the sides of the vessel passes through 
 only a short column of the drug, soon striking the 
 sides of the percolator and therefore not becoming 
 nearly saturated with the soluble constituents of 
 the drug. In a percolator which is nearly cylindrical 
 the columns of drug are more nearly uniform in 
 length, and the drug is consequently more uniformly 
 exhausted. 
 
 Why is a conical percolator desirable when the 
 menstruum is strongly aqueous? Water swells the 
 drug much more than alcohol, and the conical per- 
 colator gives the drug a chance to expand. 
 
 Why is it desirable to have a percolator with a 
 stop-cock? Because the rate of flow can be much 
 more easily controlled. 
 
 Why must tin percolators not be used in making 
 fluid extracts of nux vomica, conium, and sangui- 
 naria? Because the menstruums for these contain 
 acid which would attack the percolator. 
 
 Why is the drug dampened before being put into 
 the percolator? The dampened drug can be packed 
 more firmly and uniformly, and the finer particles 
 
16 WHYS IN PHARMACY. 
 
 of the drug are not so liable to be washed down to 
 the apex of the percolator. 
 
 Why is it advisable to allow the drug to stand 
 after dampening before being put into the percolator? 
 Because the drug has a chance to swell, and there 
 is not the liabiUty of its becoming packed so hard 
 in the percolator as to prevent the flow of the men- 
 struum. 
 
 Why should the drug be packed in layers and 
 not be put all into the percolator at one time and 
 packed? If all is put in at once it will be packed 
 too tight at the top and not tight enough at the 
 bottom. 
 
 Why can a drug be packed firmly when the 
 menstruum is alcohol? Because alcohol does not 
 swell the drug, does not dissolve so much mucilaginous 
 matter, and so does not become so thick and viscid. 
 
 Why should the drug at the bottom of the perco- 
 lator be packed more loosely than that at the top? 
 Because, in cases of certain drugs, when the men- 
 struum has reached the lower portion of the drug 
 it is so loaded with the matter which has been 
 dissolved that it is too thick to run through the 
 drug if it is tightly packed. 
 
 Why is it advisable to put a disk of paper or a 
 sieve on the top of the drug in the percolator? 
 Unless something of the kind is used the menstruum, 
 when it is poured on, will wash a cavity in the 
 drug, and this will tend to prevent the menstruum 
 from passing through uniformly. 
 
PREPARATIONS. 17 
 
 Why is the drug macerated for forty-eight hours 
 before percolating? This is for the purpose of allow- 
 ing the menstruum to permeate every particle of the 
 drug and dissolve the active matter. 
 
 Why must the drug be kept covered with the 
 menstruum during percolation? If. when fresh 
 menstruum is poured on, the menstruum has been 
 allowed to drain off, it will rush through between 
 the particles of drug without entering them or 
 dissolving the matter contained in them. 
 
 Why should percolation proceed slowly? So as 
 to give the menstruum an opportunity to dissolve 
 all of the matter that it will, thus reducing the 
 amount of alcohol used, and the amount of evapo- 
 ration necessary. 
 
 Why is evaporation necessary in making fluid 
 extracts? Because the standard for fluid extracts 
 requires that one cubic centimeter shall represent 
 one gram of the drug, and it is impossible to exhaust 
 the drug without getting more percolate than this; 
 drugs require from two to five times their quantity 
 of menstruum. 
 
 Why is the second percolate evaporated down 
 to a soft extract instead of only so far, that with 
 the reserved portion, it will make up the required 
 amount? By the time the evaporation has been 
 carried to the point where the residue will give the 
 required amount with the reserved portion, all of 
 the alcohol has been driven off, leaving an aqueous 
 mixture, and the water of tliis will cause precipita- 
 
18 WHYS IN PHARMACY. 
 
 tion when added to the reserved portion; it is neces- 
 sary therefore to evaporate off the water. 
 
 Why does the quantity of the first percolate — the 
 reserved portion — vary with different drugs? Be- 
 cause different drugs yield different quantities of 
 extractive matter when the second percolate is 
 evaporated. When the drug yields a large quan- 
 tity of extractive matter the quantity of the reserved 
 first percolate is smaller, so that it can be mixed 
 with the residue without getting too large a volume 
 of the finished product. 
 
 Why is it important that the first percolate con- 
 tain most of the active principle? Because the 
 first percolate is not heated, and heat often destroys 
 some of the active principles. 
 
 Why is a clear solution not obtained when the 
 residue from the second percolate is mixed with 
 the first percolate? Because some of the extractive 
 matter which is dissolved by the original menstruum 
 is rendered insoluble by heat in evaporating. 
 
 Why is it best to keep the temperature of evapora- 
 tion down to about 50° C. ? Because higher heat in 
 the presence of moisture frequently decomposes the 
 active principles. 
 
 Why do fluid extracts deposit solid matter after 
 being made? Because if heat has been used the 
 extractive matter that has been changed precipitates 
 slowly; moreover, change in the temperature and 
 light, and the loss of alcohol, cause a deposit of 
 inert matter. 
 
PREPARATIONS. 19 
 
 Why does precipitation sometimes take place in 
 a percolate although the same strength of alcoholic 
 menstruum is used throughout? Because the sol- 
 vent power of the menstruum varies at different 
 stages of the percolation. 
 
 Why tioes the solvent power of the menstruum 
 vary at different stages of the percolation? The 
 menstruum dissolves certain principles out of the 
 drug, and the solution so made dissolves other 
 matter that is not soluble in the original menstruum. 
 
 Why is glycerin used as part of the menstruum 
 in making some fluid extracts? Glycerin plays the 
 part of a preservative in some cases and in others 
 it dissolves tannin and keeps it from precipitating 
 subsequently. 
 
 Why is glycerin put into the first part of the men- 
 struum only and not in all of the menstruum? Glyc- 
 erin is non- volatile and cannot be evaporated with 
 the alcohol and water in evaporating the second 
 percolate; consequently the volume of the finished 
 product would be too large. 
 
 Why is a fluid extract made by repercolation 
 better than one made by simple percolation? Be- 
 cause it does not precipitate so much and has not 
 been hurt by heat. 
 
 Why is repercolation not more used than it is? 
 The objections are that more time is required, and 
 besides some of the processes require the keeping 
 of dilute percolates. 
 
 Why is it best to keep fluid extracts in amber- 
 
20 WHYS IN PHARMACY. 
 
 colored bottles? Light causes decomposition and 
 precipitation. Blue glass does not protect. 
 
 Why is the word ''Radicis'^ introduced into the 
 official title of the fluid extract of belladonna? To 
 show that it is made from the root, the extract and 
 tincture being made from the leaves. *" 
 
 Why is acetic acid used in fluid extract of conium? 
 The acid converts the alkaloid coniine into the ace- 
 tate, which is more stable and less easily volatilized. 
 
 Why is acetic acid used in fluid extract of ergot? 
 To make the alkaloids more stable. 
 
 Why is ammonia used in fluid extract of licorice? 
 Glycyrrhizin probably occurs as the acid ammonium 
 salt of glycyrrhizic acid. Ammonia converts it into 
 the neutral salt, which is more soluble and sweeter. 
 
 Why is glycerin used in the fluid extract of gly- 
 cyrrhiza? As a preservative (the amount of alcohol 
 being small) and to prevent precipitation. This fluid 
 extract will now mix with water without precipita- 
 tion. 
 
 Why is glycyrrhiza exhausted with boihng water? 
 This is a good solvent for the sweet principle. The 
 concentrated percolate is mixed with alcohol to pre- 
 cipitate albuminous matter. The filtered hquid is 
 evaporated to get rid of most of the alcohol as the 
 finished product only contains about twenty per cent, 
 by volume of official alcohol. 
 
 Why is lupuhn put into the percolator without 
 dampening? Lupulin is so resinous that when 
 moistened with alcohol it makes a mass difficult to 
 
PREPARATIONS. 21 
 
 pack in such a manner that the menstruum will run 
 through. 
 
 Why is acetic acid used in fluid extract of nux 
 vomica? It makes the alkaloid more soluble and 
 also helps to soften the drug so that it may be more 
 readily extracted. Digestion softens the drug. 
 
 Why are two layers sometimes seen in the fluid 
 extract of nux vomica after standing? Nux vomica 
 contains quite a large amount of oil which is left in 
 the residue after evaporating the second percolate, 
 and which is not dissolved in the first percolate since 
 that is already saturated with oil. 
 
 Why is fluid extract of wild cherry made without 
 evaporation? Hydrocyanic acid is the active prin- 
 ciple and is readily soluble in water. It is very 
 volatile and there would be none in the residue if 
 evaporation were directed. 
 
 Why is magnesium oxide used in making aromatic 
 fluid extract of cascara? It destroys the bitter prin- 
 ciple or renders it insoluble. The drug is dried to 
 allow the use of a uniform menstruum. 
 
 Why is acetic acid used in fluid extract of blood- 
 root? It makes the alkaloid more soluble and also 
 prevents the subsequent precipitation of matter. 
 
 Why is solution of potassium hydroxide used in 
 fluid extract of senega? It combines with pectin 
 to form a soluble compound and thus prevents the 
 gelatinization which would otherwise take place. 
 
 Why is such strong alcohol used in making fluid 
 extract of senega since a more dilute alcohol would 
 
22 WHYS IN PHARMACY. 
 
 take out the active principle? The stronger men- 
 struum does not take out so much pectin. 
 
 Why is sodium hydroxide used in fluid extract of 
 taraxacum? To prevent subsequent precipitation. 
 This fluid extract usuaUy gives a very heavy deposit 
 on standing. 
 
 Why is triticum exhausted with boiUng water, 
 evaporated, treated with alcohol, and filtered? To 
 get rid of albuminous matter. 
 
 EXTRACTS. 
 
 Why, in making some extracts, is the menstruum 
 water; and why, in making corresponding fluid ex- 
 tracts, is it a mixture of alcohol and water? Alcohol 
 is necessary as a preservative in fluid extracts even 
 when the active principles are soluble in water. In 
 most sohd extracts no preservative is necessary. 
 
 Why does an extract made by drying the juice of 
 a fresh drug vary more than that made from a dried 
 drug? The amount of inert matter in the juice 
 varies more than that dissolved by a given men- 
 struum. 
 
 Why does the U. S. P. not direct the evaporation 
 to dryness and powdering of all solid extracts? Be- 
 cause the extra amount of heat required would seri- 
 ously impair the therapeutic value of some of them. 
 
 Why do extracts vary in strength? Manufacturers 
 have different ideas as to what is meant by ''pilular 
 consistency"; some extracts absorb moisture on 
 
PREPARATIONS. 23 
 
 keeping, and others become more dry. Different 
 samples of the drug vary in the amount of active 
 matter and inert matter which may be dissolved. 
 More heat is used by some manufacturers than others. 
 
 Why do some unscrupulous manufacturers use a 
 m.enstruum containing more water than that directed 
 by the U. S. P.? By so doing they save alcohol and 
 at the same time frequently get a larger yield of 
 extract, since water has a greater tendency to dis- 
 solve extractive matter. 
 
 Why is glycerin used in some extracts? It is used 
 to prevent the extract from becoming hard and tough. 
 
 Why is powdered liquorice used in making some 
 extracts? To keep the extract in the form of a 
 powder, many being somewhat hygroscopic. 
 
 Why are extracts sometimes better when made 
 by evaporating the fluid extract than by following 
 the U. S. P., 1890, directions? Because the larger 
 portion of the active principles will not have been 
 heated so long. 
 
 Why does the U. S. P. direct in making extracts 
 of belladonna, henbane, and physostigma, that the 
 first portion of the percolate be reserved and evapo- 
 rated after the second percolate is evaporated? The 
 active principles of these drugs are easily decomposed 
 by heat, and the largest portions of them are sub- 
 jected to less heat by following the directions. 
 
 Why is such a large proportion of water used in 
 making extract of aloes? A small amount of water 
 makes a concentrated solution of the soluble con- 
 
24 WHYS IN PHARMACY. 
 
 stituents, and this solution dissolves the inert resin- 
 ous matter. By using a large amount of water 
 the solution is too dilute to dissolve the resin. 
 
 Why is acetic acid used in extract of colchicum? 
 It renders the alkaloid colchicine more stable and 
 soluble. 
 
 Why does the U. S. P. direct colocynth ''freed 
 from seeds" in making extract of colocynth? The 
 seeds contain quite a large percentage of fixed oil 
 which, if allowed to go into the extract, would 
 prevent the extract from being dried and pow- 
 dered. 
 
 Why is alcohol used in making compound extract 
 of colocynth? It helps to thin the melted aloes and 
 make it form a more intimate mixture with the 
 other ingredients. 
 
 Why are water and hydrochloric acid used in 
 making extract of ergot? To get rid of foreign and 
 inert matter and make an extract that is soluble in 
 water. Sodium carbonate is used to neutralize the 
 
 acid. 
 
 Why is cold water preferable to hot water in 
 making extract of gentian? Cold water dissolves 
 the active principles as well as hot water, while it 
 does not take out so much inert matter. 
 
 Why is the aqueous extract of gentian boiled? 
 BoiUng coagulates the albuminous matter, which is 
 strained out. 
 
 Why are gentian and glycyrrhiza macerated for 
 twenty-four hours after dampening before being put 
 
PREPARATIONS. 25 
 
 into percolators in making the extracts of these 
 drugs? Water is the menstruum used and it causes 
 the drugs to swell considerably; by allowing them 
 to swell before putting them into percolators there is 
 less danger of their getting packed too tight. 
 
 Why does the U. S. P. introduce the word ^^ Purum " 
 in the title of extract of glycyrrhiza? To distinguish 
 it from the commercial extract, which is not entirely 
 soluble. 
 
 Why is ammonia used in the extract of glycyrrhiza? 
 To make the glycyrrhizin more soluble and sweeter. 
 
 Why is hematoxylon boiled with water? The 
 astringent principle is not very readily extracted 
 by cold water, but is by boihng water. 
 
 Why is acetic acid used in extract of nux vomica? 
 It helps to soften the drug and converts the alkaloids 
 into the soluble acetates. Extracting with acetic 
 acid and water leaves behind the fixed oil which 
 caused the troublesome part of the 1890 method. 
 Alcohol added to the concentrated aqueous extract 
 precipitates inert matter. 
 
 Why is the aqueous infusion of quassia boiled 
 and strained? To remove the albuminous matter. 
 
 GLYCERITES. 
 
 Why should the glycerites be protected from 
 the air? The glycerin present in them is hygro- 
 scopic. 
 
 Why is a heat of 140° C. directed in making 
 
26 WHYS IN PHARMACY. 
 
 glycerite of starch? Because a heat much lower 
 than this would not rupture the enveloping mem- 
 brane of the starch granule. 
 
 Why does the U. S. P. direct the heating of 
 glycerin and boric acid until a definite weight is 
 obtained, in making glycerite of boroglycerin? 
 Because when this weight is reached it is known 
 that the water is driven off and the reaction is 
 complete. 
 
 Why should glycerite of boroglycerin not be 
 poured into bottles containing even a httle rinsing 
 water? Water combines with boroglycerin^ forming 
 glycerin and boric acid. 
 
 INFUSIONS. 
 
 Why is an infusion of a drug sometimes active 
 when the decoction of the same drug is inert? The 
 heat necessary in making the decoction destroys or 
 volatihzes the active principle. 
 
 Why is it not admissible to make an infusion by 
 diluting a fluid extract? A fluid extract, being 
 made with an alcoholic menstruum, does not contain 
 the same active principles that would be extracted 
 by water in making the infusion. 
 
 Why are infusions generally incompatible with 
 metalhc and alkaloid salts? Because they contain 
 tannic acid. 
 
 Why is either rain or distilled water better than 
 hard water in maJjing infusions? Because they do 
 
PREPARATIONS. 27 
 
 not contain saline salts that sometimes cause precipi- 
 tation. 
 
 Why are earthen vessels best for making infusions? 
 They are less hkely to be broken by the heat, and 
 they retain heat longer than most other vessels. 
 
 Why should infusions not be macerated too long? 
 Tannin and other objectionable matter will be taken 
 out to a greater extent. 
 
 Why is aromatic sulphuric acid used in making 
 the infusion of cinchona, 1890? The acid converts 
 the alkaloids into soluble sulphates, and the aromatics 
 make the preparation more palatable. 
 
 Why is alcohol used in infusion of digitaUs? As 
 a preservative. 
 
 Why must cold water be used in making infusion 
 of wild cherry? Hot water would coagulate the 
 ferment, preventing the formation of the essential 
 oil of almonds, and would also volatihze the oil 
 even if formed. 
 
 LINIMENTS. 
 
 Why does an old rancid oil make a better liniment 
 when mixed with an alkali than a fresh oil? The 
 free fat acid combines more readily, forming soap 
 which helps to suspend the remainder of the oil. 
 For the same reason oleic acid is now one of the in- 
 gredients of ammonia liniment. 
 
 Why is alcohol used in ammonia liniment? It is 
 put in to thin the liniment and prevent it from 
 
28 WHYS IN PHARMACY. 
 
 getting too thick. It will also aid the chemical 
 reaction. 
 
 Why does ammonia liniment sometimes become 
 solid? The ammonia, acting on the oil, forms a 
 soap which is the cause of solidification. In lime 
 liniment a solid soap of lime is formed. 
 
 Why is powdered or granulated soap preferable 
 to bar soap in making soap liniment? It is more 
 constant in its amount of water. A nearly saturated 
 solution is wanted, and it would be difficult to get 
 that with bar soap without getting an excess. 
 
 Why is soap liniment allowed to stand for twenty- 
 four hours before filtering? Soap contains some 
 sodium palmitate, which goes into solution at first, 
 but which afterwards precipitates and is then 
 filtered out. 
 
 Why does soap frequently precipitate even when 
 the directions are followed? The liniment is intended 
 to be a nearly saturated solution of soap; sometimes, 
 however, an excess of soap is unintentionally put in 
 through the fact that it contained less water, and 
 this excess is often precipitated by a change in 
 temperature or evaporation of alcohol. 
 
 Why, in making chloroform liniment, is there 
 sometimes a separation into two layers? This 
 separation is due to the use of an excess of water 
 or a deficient amount of alcohol in making the 
 soap liniment. 
 
PREPARATIONS. 29 
 
 SOLUTIONS. 
 
 Why does the U. S. P. recognize the solution of 
 arsenic trioxide as solution of arsenous acid? The 
 tri oxide combines with water to form the true 
 acid. 
 
 Why is hydrochloric acid used in making solution 
 of arsenous acid? It aids the solution of the arsenic 
 trioxide and does not cause a chemical reaction. 
 
 Why was solution of arsenous acid formerly called 
 solution of chloride of arsenic? Because it was 
 thought that chemical reaction ensued in its manu- 
 facture, forming the chloride of arsenic. 
 
 Why is sodium bicarbonate used in estimating 
 arsenous acid? Because the iodine reacts with ar- 
 senous acid in an alkaline solution only. Hydriodic 
 acid is formed and must be neutralized. 
 
 Why should only ^translucent pieces" of ammo- 
 nium carbonate be used in making solution of ammo- 
 nium acetate? Because the opaque pieces contain 
 more ammonium bicarbonate, and the proportion of 
 acetic acid used would therefore have to vary with 
 the amount of bicarbonate present. 
 
 Why should solution of ammonium acetate be 
 made up fresh when wanted? The fresh solution 
 contains some carbon dioxide which makes the prepa- 
 ration more palatable, and this is lost on keeping 
 the solution. 
 
 Why must the container for solution of ammonium 
 
30 WHYS IN PHARMACY. 
 
 acetate be not stoppered at once? Because carbon 
 dioxide is formed and might exert sufficient pressure 
 to burst the bottle. 
 
 Why does solution of ammonium acetate some- 
 times give precipitates with metallic and alkaloid 
 salts? The solution is sometimes alkaline, due to an 
 excess of carbonate or to an insufficient amount of 
 acid used. 
 
 Why does solution of ammonium acetate, although 
 neutral, have a taste of ammonia? The loosely 
 combined soda of the saliva liberates ammonia. 
 
 Why is it that the solution of arsenous and mer- 
 curic iodides is clear, when the mercuric iodide is 
 practically insoluble in water? Arsenous iodide is 
 soluble in water and mercuric iodide is soluble in 
 solutions of iodides, generally forming double com- 
 pounds. 
 
 Why does Donovan's solution change color on 
 keeping? Iodine is gradually liberated, giving a red 
 color. 
 
 Why, in making lime water, is the water rejected 
 that is put on to the lime during the first half 
 hour? Lime frequently contains sodium carbonate 
 and other impurities that are soluble in water and 
 that are not desired in lime water. 
 
 Why is an excess of lime left in the lime-water 
 container? Lime water absorbs carbon dioxide from 
 the air, forming calcium carbonate, which is pre- 
 cipitated; an excess of lime present keeps the 
 water saturated at all times. 
 
rREPARATIONS. 31 
 
 Why does heating a good sample of clear lime 
 water produce a turbidity? Because calcium hy- 
 drate is less soluble in hot than in cold water. 
 
 Why is the mixture of potassium chlorate and 
 hydrochloric acid warmed in a flask plugged with wet 
 cotton in making compound solution of chlorine? 
 Heat aids chemical reaction and the formation of 
 chlorine. The wetted cotton allows the air to escape 
 without losing much chlorine, the water catching it. 
 Water is then passed through the cotton to recover 
 the chlorine. This formula is simpler than that of 
 chlorine water (1890) which it replaces, but it contains 
 other substances. 
 
 Why does the U. S. P. direct the use of iron wire in 
 making solution of ferric chloride? Because it is 
 comparatively pure iron. 
 
 Why is an excess of iron used in making solutions of 
 ferric chloride? The reaction takes place more readily. 
 
 Why is the mixture of iron and hydrochloric acid 
 heated before filtering? So as to bring the reaction 
 to completion, and the salt into solution. 
 
 Why is hydrochloric acid added to this filtrate of 
 ferrous chloride? To prevent the formation of any 
 oxychloride ; moreover, hydrochloric acid is necessary 
 when the ferrous salt is changed to ferric, since ferric 
 chloride contains a larger proportion of chlorine which 
 must be gotten from the hydrochloric acid. 
 
 Why is nitric acid used in making solution of ferric 
 chloride? It oxidizes the ferrous to ferric chloride. 
 
 Why is hydrochloric acid added to the solution of 
 
32 WHYS IN PHARMACY. 
 
 ferric chloride just before making up to the required 
 amount with water? Nearly all the free hydro- 
 chloric acid is driven off in getting rid of the nitric 
 acid; and if an excess of hydrochloric acid is not 
 present, oxychloride of iron is precipitated on allow- 
 ing the solution to stand. 
 
 Why is a part of ferric chloride converted into ferric 
 hydroxide, and this dissolved in the remaining 
 solution of ferric chloride, in making solution of 
 dialyzed iron? The solution so obtained contains 
 basic ferric chloride; this does not pass through the 
 filter as does ferric chloride. 
 
 Why should the solution of ammonium acetate 
 ''not be alkaline" in making solution of iron and 
 ammonium acetate? Because iron would be pre- 
 cipitated as a basic salt. 
 
 Why is nitric acid used in making solution of ferric 
 subsulphate? It oxidizes the ferrous to ferric iron. 
 
 Why is sulphuric acid used in making Monsel's 
 solution? Because iron in the ferric condition has a 
 larger proportion of sulphuric acid than it has in 
 the ferrous state. 
 
 Why is the ferrous sulphate added in portions to 
 the mixture of sulphuric and nitric acids in making 
 Monsel's solution? Because, if added all at once 
 the amount of nitric oxide gas formed would be 
 sufficient to cause the expulsion of some of the liquid. 
 
 Why, in making MonseFs solution, is more nitric 
 acid added if, on adding a few drops, red fumes are 
 given off? The formation of red fumes shows that 
 
PREPARATIONS. 33 
 
 all of the ferrous sulphate has not been changed to the 
 ferric compound and so more nitric acid is necessary. 
 
 Why, in making MonseFs solution, does the liquid 
 become almost black, and then lighter on further 
 heating? Some of the nitric oxide combines with the 
 ferrous sulphate, forming this dark compound, which 
 is afterwards decomposed by the heat. 
 
 Why does MonseFs solution separate a solid when 
 mixed with one half its volume of sulphuric acid, 
 while solution of ferric sulphate does not? Because, 
 in the concentrated MonseFs solution, the ferric sul- 
 phate is not soluble in the sulphuric acid, MonseFs 
 solution being stronger than the solution of the 
 sulphate of iron. 
 
 Why should the solution of ferric subsulphate be 
 kept in a moderately warm place protected from 
 Hght? When chilled it solidifies and light reduces 
 it. 
 
 Why is solution of mercuric nitrate made from the 
 red oxide? The solution is more easily made from 
 it than from the metallic mercury. 
 
 Why is potassium iodide used in making com- 
 pound solution of iodine? Iodine is nearly insoluble 
 in water, but readily soluble in an aqueous solution 
 of an iodide. 
 
 Why does solution of magnesium citrate some- 
 times precipitate on keeping? The normal magne- 
 sium citrate is less soluble than the acid citrate and 
 when the excess of citric acid is neutralized the 
 magnesium citrate is precipitated. 
 
34 WHYS IN PHARMACY. 
 
 Why is the carbon dioxide, liberated by the action 
 of citric acid on magnesium carbonate, not utiHzed 
 in carbonating the solution of magnesium citrate, 
 instead of putting in potassuim bicarbonate? The 
 amount of carbon dioxide from the magnesium 
 carbonate is too great to use all of it and it would 
 be difficult to regulate. 
 
 Why should bottles of magnesium citrate solution, 
 and other bottles containing water and gas under 
 pressure, be kept on their sides? To keep the 
 stoppers wet and swollen so as to prevent the 
 escape of gas. 
 
 Why should distilled water that has been recently 
 boiled always be used in making solution of lead 
 subacetate? Because ordinary water is apt to contain 
 some non-volatile substances that would precipitate 
 the lead, and distilled water, unless recently boiled, 
 will contain some carbon dioxide and oxygen ab- 
 sorbed from the air, which will also precipitate the 
 lead. 
 
 Why is there a white residue left after boiling 
 lead acetate and lead oxide together with water? 
 Because there is formed a basic, insoluble lead 
 acetate besides the compound that goes into solu- 
 tion. 
 
 Why does a solution of lead subacetate always 
 deposit a white solid on exposure to air? It absorbs 
 carbon dioxide and forms lead carbonate. 
 
 Why is compound tincture of lavender used in 
 Fowler's solution? It gives flavor and color. 
 
PREPARATIONS. 35 
 
 Why is it advised to not keep Fowler's solution 
 longer than a year? It is said to be slowly oxidized 
 to an arsenate which is less active. 
 
 Why should solution of potassium citrate be 
 made up fresh? It loses its carbon dioxide and 
 soon spoils. 
 
 Why should solution of chlorinated soda be kept 
 in glass-stoppered bottles protected from the light? 
 Chlorine attacks ordinary cork stoppers, and light 
 tends to decompose the hypochlorite. 
 
 Why is potassium bicarbonate used in preference 
 to potassium carbonate in making solution of potas- 
 sium hydroxide (1890)? Because it is purer. 
 
 Why is potassium bicarbonate in solution boiled 
 until effervescence ceases in making solution of 
 potassium hydroxide (1890)? So as to convert it 
 into potassium carbonate, which reacts better, 
 calcium acid carbonate being somewhat soluble. 
 
 Why are the mixture of lime and water and the 
 solution of potassium carbonate heated before 
 mixing? If mixed while hot the calcium carbonate 
 is precipitated in a denser form and will settle 
 more quickly. 
 
 Why is the solution separated from the insoluble 
 matter by decantation or siphoning, rather than by 
 filtration? In filtering through paper the alkali 
 attacks the paper. 
 
 Why are 6.0 grams of potassium hydroxide used 
 in making 100 grams of a five per cent, solution? 
 Potassium hydroxide generally contains moisture 
 
36 WHYS IN PHARMACY. 
 
 and carbon dioxide, the U. S. P. allowing as much 
 as fifteen per cent, of impurities, and allowance is 
 made for these in making the solution. 
 
 Why must solution of potassium hydroxide be 
 protected from the air? It absorbs carbon dioxide 
 readily. 
 
 Why should solution of potassium hydroxide be 
 kept in green glass bottles rather than in flint? 
 Potassium hydroxide dissolves green glass less 
 readily. 
 
 Why does Labarraque's solution effervesce when 
 an acid is added to it? An excess of sodium car- 
 bonate is generally present, and an acid liberates 
 carbon dioxide. Chlorine is also liberated. 
 
 AVliy is nitric acid used in making solution of 
 zinc chloride? Zinc frequently contains iron as an 
 impurity. This is dissolved by hydrochloric acid, 
 forming ferrous chloride, and nitric acid converts 
 it into a ferric compound so that it may be more 
 completely precipitated. Ferrous salts are not com- 
 pletely precipitated by hydrates or carbonates. 
 
 Why is the solution of zinc chloride evaporated 
 and fused? To get rid of the nitric acid. 
 
 Why should the temperature of fusion be below 
 115° C? So as to avoid volatilization and decom- 
 position of the zinc chloride. 
 
 Why is zinc carbonate used in making solution 
 of zinc chloride? It precipitates the iron as the 
 hydroxide, and, being insoluble, the excess can be 
 filtered out; no impurity is therefore introduced. 
 
PREPARATIONS. 37 
 
 Why is solution of zinc chloride separated by 
 decantation instead of by filtration? The con- 
 centrated solution, being caustic, would attack 
 filter paper. 
 
 Why is ammonia used in solution of carmin, N. F. ? 
 Ammonia forms a soluble compound with carmin. 
 
 Why is iron and ammonium sulphate used in 
 making solution of hypophosphite of iron, N. F.? 
 It is nearly neutral and the iron hypophosphite is 
 more completely precipitated. 
 
 Why is potassium citrate used in making solution 
 of hypophosphite of iron, N. F.? The potassium 
 citrate makes the hypophosphite soluble in water, 
 perhaps by forming a double compound. 
 
 Why is diluted hypophosphorous acid used in 
 solutions of ferrous iodide and ferrous chloride, 
 N. F.? It retards or prevents oxidation of the 
 ferrous salts to the ferric condition. 
 
 Why is lead carbonate preferred in clarifying the 
 solution of gutta-percha, N. F.? Because it is heavy 
 and will settle to the bottom notwithstanding the 
 solution is very viscid. 
 
 Why is sodium bicarbonate used in pancreatic 
 solution, N. F.? To make the solution alkaline. 
 Pancreatin acts best in alkaline fluids. 
 
 Why is talcum used in preference to calcium 
 phosphate in filtering aromatic solution of pepsin, 
 N. F.? This solution contains hydrochloric acid 
 which would dissolve the phosphate, but does not 
 act on talcum. 
 
38 WHYS IN PHARMACY. 
 
 Why is sodium bicarbonate used in making solu* 
 tion of saccharin, N. F.? To make the saccharin 
 soluble. 
 
 Why is it that the N. F. directs one gram of 
 sodium arsenate to 600 cubic centimeters of water 
 in making Pearson's solution, and then states that 
 the solution is one tenth as strong as the U. S. P. 
 solution, which is one per cent, in strength? The 
 U. S. P. directs the use of the anhydrous salt, whereas 
 the N. F. uses the crystallized, which has seven 
 molecules of water of crystaUizatJon. 
 
 Why is carbon dioxide evolved in DobelFs solu- 
 tion, since carbolic acid does not decompose sodium 
 bicarbonate? Glycerin decomposes the borax, form- 
 ing glycerol borate and sodium metaborate; water 
 decomposes this glycerol borate, forming glycerin 
 and boric acid, and the boric acid liberates carbon 
 dioxide from the bicarbonate. 
 
 Why is the soluble essence of ginger, N. F., clas- 
 sified with solutions? Possibly because it does not 
 contain much alcohol, although it has nearly as 
 much as the soluble tincture of Tolu. 
 
 MASSES. 
 
 Why is boiling distilled water used to dissolve the 
 ferrous sulphate in making mass of carbonate of 
 iron? It is free from oxygen and so will not oxidize 
 the ferrous salt to the ferric condition. 
 
 Why is the solution of ferrous sulphate added to 
 
PREPARATIONS. 39 
 
 the solution of carbonate and not the carbonate 
 to the iron? By adding the carbonate to the iron, 
 there would be more danger of getting a basic 
 instead of a normal carbonate of iron. 
 
 Why is the bottle filled with water before putting 
 aside for settling? In order to exclude the air as 
 far as possible to prevent oxidation. 
 
 Why is syrup added to the solution of ferrous 
 sulphate in making mass of iron? Sugar prevents 
 or retards the oxidation of the ferrous salt. 
 
 Why is the washing of ferrous carbonate by de- 
 cantation preferable to washing on a filter? There is 
 less exposure to the oxygen of the air. 
 
 Why does mass of carbonate of iron sometimes 
 become brown on keeping? It oxidizes to ferric oxide 
 which is brown. 
 
 Why is it that carbonate of iron thus prepared 
 has a green color when pure ferrous carbonate is 
 white? Because all the commercial ferrous carbonate 
 contains some ferric salt, and this green product is a 
 combination of ferrous and ferric iron. 
 
 Why are honey and glycerin good for extin- 
 guishing mercury? Because they are viscid and keep 
 the globules of mercury apart. 
 
 Why is mass of mercury called '^blue mass?" 
 Mercury in a very fine state of subdivision has a 
 bluish color. 
 
 Why is w^ater used in making mass of copaiba 
 (1890) ? It aids the chemical reaction. 
 
 Why is it that copaiba solidifies with such a small 
 
40 WHYS IN PHARMACY. 
 
 amount of magnesia? The magnesia combines with 
 the resin, forming a bulky resin soap that sohdifies 
 the oil Magnesia employed with the oil of copaiba 
 does not cause solidification. 
 
 Why should care be used in choosing copaiba for 
 making mass or pills of copaiba? Copaiba varies in 
 viscosity and composition, and the thickest contain- 
 ing the most resin is the best. 
 
 MIXTURES. 
 
 Why should chalk mixture be made when wanted? 
 It quickly becomes sour upon keeping, and the acid 
 formed liberates carbon dioxide. 
 
 Why is sugar used in compound iron mixture? To 
 prevent or retard the oxidation of the ferrous car- 
 bonate. 
 
 Why does compound iron mixture turn brown on 
 keeping? The green ferroso-ferric carbonate oxi- 
 dizes to red-brown ferric oxide. 
 
 Why is it better to make a concentrated aqueous 
 solution of chloral hydrate and dissolve the extracts 
 in this rather than to follow the N. F. directions in 
 making the compound mixture of chloral and potas- 
 sium bromide? Less of the resinous matter is sub- 
 sequently precipitated. A strong solution of chloral 
 hydrate is a good solvent for resins. 
 
PREPARATIONS. 41 
 
 MUCILAGES. 
 
 Why is mucilage of acacia of but little service as a 
 suspending agent when alcohol is present in large 
 proportions? Acacia is insoluble in alcohol; it is 
 thrown out of aqueous solution by it, and the 
 emulsion is broken up. 
 
 Why is powdered acacia -harder to dissolve in water 
 than the granulated? In the preparation for granu- 
 lation, acacia loses about two per cent, of moisture, 
 but in getting it dry enough to powder it loses about 
 ten per cent, of moisture. Moreover, powdered 
 acacia makes masses with water which are hard 
 to rub out. 
 
 Why is lime water used in mucilage of acacia? 
 It neutralizes acidity and tends to prevent decom- 
 position. 
 
 Why is it better to add only a small amount of 
 water at first in making mucilage of acacia from the 
 powdered acacia? The lumps that always form can 
 be rubbed out much more easily and quickly. 
 
 Why is mucilage of tragacanth better than acacia 
 as a suspending agent when ferric salts or borax 
 are present? It is not coagulated by these. 
 
 Why does it take a smaller amount of tragacanth 
 than acacia to act as an emulsifying or suspending 
 agent? Only a portion of tragacanth is soluble in 
 water, and that which does not dissolve swells and 
 in so doing takes up a large amount of water before 
 it makes a thin mixture. 
 
42 WHYS IN PHARMACY. 
 
 Why is chondrus, washed with water before 
 making it into a mucilage? To free it from salt 
 and foreign matter. 
 
 OLEATES. 
 
 Why are oleates of the metals preferably made 
 by double decomposition? Because oleic acid com- 
 bines slowly with a metallic oxide or hydroxide. 
 
 Why is the oleate of mercury best made without 
 heat? If even a little heat is used the oleate decom- 
 poses much more quickly, ultimately precipitating 
 metallic mercury. 
 
 Why is it generally necessary to add acetic acid to 
 clear a mixture of lead acetate and water in making 
 oleate of lead, N. F.? Lead acetate contains a Httle 
 lead carbonate, which is insoluble in water, but which 
 is converted into the acetate by the acid. 
 
 Why must a large excess of acetic acid be avoided 
 in making oleate of lead, N. F.? Acetic acid would 
 liberate oleic acid from sodium oleate, making the 
 oleate soft and sticky. 
 
 Why is it necessary to add some acetic acid to the 
 solution of soap in making lead oleate? Soap is 
 sometimes strongly alkahne, and the lead would be 
 precipitated as the hydroxide or carbonate instead 
 of the oleate. 
 
 Why is boihng water used in washing lead oleate? 
 The heat softens or liquefies the oleate and thus gives 
 the water a better chance to dissolve out the sodium 
 acetate. 
 
PREPARATIONS. 43 
 
 Why is the free alkaloid used in making an oleate 
 of an alkaloid? The oleic acid combines with it to 
 form a compound soluble in the acid. Alcohol is 
 used to dissolve the alkaloid and aid reaction. The 
 ordinary alkaloidal salts do not dissolve in oleic 
 acid or olive oil. 
 
 Why are metallic oleates best made of normal 
 strength? They keep better. 
 
 OLEORESINS. 
 
 Why is acetone used in place of ether in making 
 oleoresins? It is not so volatile or inflammable and 
 is a good solvent for oils and resins, combining the 
 solvent properties of alcohol and ether. 
 
 Why should the oleoresin of male fern be stirred 
 up before taking any out of the container? Filicic 
 acid, the active principle, separates on standing. 
 
 Why should capsicum not be percolated to exhaus- 
 tion in making oleoresin of capsicum? The last 
 part of the percolation removes a large proportion 
 of inert fatty matter and but a small proportion 
 of active matter. 
 
 Why should oleoresin of cubebs be decanted? 
 Inert cubebin settles out on standing. 
 
 Why is lupuHn ''very lightly" pressed in making 
 the oleoresin? It yields so much soluble matter 
 that the acetone solution would not be able to 
 pass through the drug. 
 
44 WHYS IN PHARMACY. 
 
 OILS. 
 
 Why do fixed oils vary in color? On account of 
 oxidation products and the presence of other foreign 
 matter, such as chlorophyll. 
 
 Why do the melting-points of different samples 
 of the same kind of fat vary? The melting-point 
 generally varies with the proportion of olein and 
 stearin, and this varies with the season of the year 
 and with the process of obtaining the fat. On 
 account of this variation the determination of the 
 melting-point is of but little value in testing for 
 adulterations. 
 
 Why do non-drying oils undergo decomposition? 
 Some authorities say that rancidity is due to the 
 action of ferments liberating the free fat acids, and 
 others say that rancidity results from the direct 
 oxidation of the fat by oxygen and light acting 
 simultaneously. 
 
 Why is the determination of the specific gravity 
 of but little value in determining the identity or 
 adulteration of an oil or fat? The specific gravity 
 varies with the process of obtaining the fat, the proc- 
 ess of purifying it, the presence of free fat acids, the 
 age, the amount of oxidation, and the temperature. 
 
 Why is mercuric chloride used with iodine in 
 making the iodine absorption tests for oils? Iodine 
 reacts only slowly with a fixed oil at ordinary tem- 
 perature, but much more readily in the presence 
 of corrosive sublimate. 
 
PREPARATIONS. 45 
 
 Why is a little heat generally used in obtaining 
 fixed oils from seeds by pressure? Heat renders 
 the oil less viscid and a larger yield is obtained, 
 but the quality is generally not so good. 
 
 Why is winter-pressed lard oil preferable to 
 summer-pressed? It contains less stearin than the 
 summer-pressed product, and therefore remains liquid 
 at a lower temperature. 
 
 Why is most of the expressed oil of almond 
 obtained from the bitter almonds and not from 
 the sweet? Although the bitter almonds contain 
 less fixed oil than the sweet, they are cheaper, and 
 the cake left from the fixed oil may be used for 
 obtaining the volatile oil. 
 
 Why is sodium hydroxide sometimes used in 
 purifying cottonseed oil? It converts a small amount 
 of fat into soap, which on settling carries much of 
 the coloring matter with it. 
 
 Why is so much cottonseed oil shipped to Mediter- 
 ranean ports? Much of the olive oil comes from 
 these ports, and cottonseed oil is used as an adulter- 
 ant or substitute for olive oil. 
 
 Why should the linseed oil used in pharmacy be 
 obtained by cold pressure? It is less acrid and not 
 so highly colored. 
 
 Why is cod liver oil used more than other oils 
 as a nutrient? It is more readily absorbed and 
 assimilated, but why it is more readily absorbed is 
 a question that has not been decided. Some say 
 that it is because the oil contains biliary principles: 
 
46 WHYS IN PHARMACY. 
 
 others think that it is because the presence of free 
 fat acids facihtates emulsification. 
 
 Why can the silver nitrate test not be depended 
 upon for the detection of cottonseed oil in olive oil? 
 Cottonseed oil can be so purified that it will not 
 give the test. 
 
 Why is castor oil boiled with water in purifying 
 it? Boiling water takes out the albuminous matter 
 and destroys the small amount of acrid poisonous 
 matter that is removed with the oil. 
 
 Why is expressed oil of almonds heated to 250° 
 C. in making phosphorated oil (1890)? To remove 
 any air and water, and to cause the separation of 
 some organic matter, all of which would tend to 
 oxidize the phosphorus if they were present. 
 
 Why is ether used in phosphorated oil (1890)? 
 It prevents oxidation and gives a more palatable 
 taste. 
 
 Why are the volatile oils that are obtained by 
 distillation usually distilled with water? They can 
 be distilled at a lower temperature and with less 
 resulting decomposition. The organic matter from 
 which oil is obtained yields less of the empyreumatic 
 substances. 
 
 Why is the '^enfleurage'^ method frequently 
 resorted to in obtaining oils? The method of 
 extracting the oil by a neutral fat is used when 
 the oil is present in small quantities and when it 
 is decomposed by heat. 
 
 Why should volatile oils be protected from light 
 
PREPARATIONS. 47 
 
 and air since they do not become rancid? Light 
 and air cause an oxidation of the oil and a destruc- 
 tion of the characteristic odor. Ozone is developed 
 by some oils. 
 
 Why do volatile oils, when dropped on paper, some- 
 times leave a stain which is not dissipated by heat? 
 The stain is due to resinous matter, usually formed 
 by oxidation. The stain can be distinguished from 
 that of a fixed oil by the fact that it dissolves in 
 alcohol. 
 
 Why is salt water used in distilling some oils, 
 such as oil of cloves? Salt raises the boiling-point 
 of water, bringing it nearer that of the oil, and is 
 used when the oil has a high boiling-point. 
 
 Why are bitter almonds macerated with water 
 for several hours before distilling? In order to 
 allow the ferment to act on the amygdalin, forming 
 the oil. Water is necessary for this reaction. 
 
 Why does oil of bitter almonds sometimes solidify 
 on keeping? The oil consists chiefly of benzaldehyde 
 which oxidizes, forming benzoic acid. 
 
 Why does the oil obtained from bitter almonds 
 keep better than the synthetic oil of bitter almonds? 
 It is claimed by some that in the natural oil the 
 hydrocyanic acid is combined with the benzaldehyde, 
 keeping it from being so easily oxidized. 
 
 Why is it customary to dry oil of bitter almonds 
 over calcium chloride? If moisture is left in it 
 tends to aid oxidation of the oil. 
 
 Why is synthetic oil of bitter almonds not good 
 
48 WHYS IN PHARMACY. 
 
 for the finer perfumes? It often contains chlorinated 
 compounds which possess unpleasant odors. 
 
 Why does oil of cassia become acid? It consists 
 largely of cinnamic aldehyde which is slowly oxidized 
 to cinnamic acid. 
 
 Why do oils of eucalyptus, cajuput, and rosemary 
 resemble one another in odor? They contain euca- 
 lyptol (cineol). 
 
 Why are green juniper berries used for obtaining 
 oil of juniper? They yield more oil than when 
 fully ripe. 
 
 Why does oil of cajuput have a green color? When 
 first distilled it contains some chlorophyll, but after 
 rectification it is colorless. If the colorless oil is 
 allowed to stand in copper containers it becomes 
 green, due to the solution of a little copper. This 
 copper cannot be detected by ammonia, as ammonia 
 does not give the characteristic blue color. 
 
 Why is benzin used in estimating cineol in oil of 
 cajuput? It dissolves the other constituents of the 
 oil but not the cineol phosphate that is formed when 
 phosphoric acid is added. 
 
 Why is potassium hydroxide used in estimating 
 eugenol in oil of cloves? It combines with eugecol 
 to form a soluble compound, the other constituents 
 not combining do not dissolve in the water. 
 
 Why is oil of lemon obtained by expression rather 
 than by distillation? The flavor is finer when 
 obtained by expression. 
 
 Why should about five per cent, of alcohol be 
 
PEEPARATIONS. 49 
 
 added to oils of lemon, orange, and bergamot as soon 
 as the retailer opens the containers? These oils 
 change very quickly, acquiring a turpentine odor and 
 taste. Alcohol preserves them. 
 
 Why do different oils of peppermint vary in their 
 solidifying points? The solidification depends on the 
 proportion of menthol present and this varies with 
 the oil. 
 
 Why does oil of patchouly have a musty odor? 
 Before the leaves are distilled they are piled in heaps 
 and allowed to undergo some degree of decomposi- 
 tion. 
 
 Why is oil of pimenta distilled from the unripe 
 fruit? The ripe fruit is nearly odorless. 
 
 Why do oils of pimenta, cloves, and bay have a 
 somewhat similar odor? They all contain a large 
 proportion of eugenol, to which the odor of the oils 
 is largely due. 
 
 Why is oil of rose solid in cool weather? It con- 
 tains a hydrocarbon which has a comparatively high 
 liquefying-point. This hydrocarbon is not the odor- 
 ous principle, although its presence is taken as an 
 indication of the purity of the oil. 
 
 Why is Indian oil of sandalwood darker than that 
 distilled in Europe? In India the distillation is pro- 
 longed and causes the formation of decomposition 
 products. 
 
 Why are sandalwood trees left on the ground some 
 months before distilling? The ants eat off the sap- 
 wood, leaving the heart-wood which yields the oil. 
 
50 WHYS IN PHARMACY. 
 
 Why is black mustard macerated with water for 
 some time before distiUing the volatile oil? In order 
 to allow the ferment to act on the glucoside sinigrin, 
 forming the oil. 
 
 Why does oil of turpentine become acid? It slowly 
 resinifies, forming abietic anhydride which is acid to 
 litmus when dissolved in alcohol. Other acids, such 
 as formic, acetic, and carbonic, are probably also 
 formed. 
 
 Why is sodium hydroxide used in rectifying oil of 
 turpentine? It neutralizes any acid and renders it, 
 as well as the resin, less volatile. 
 
 Why is old oil of turpentine used in poisoning by 
 phosphorus? It contains ozone which perhaps oxi- 
 dizes the phosphorus to less poisonous products. 
 
 Why is oil of vetivert used in perfumery? On ac- 
 count of its sparing volatihty it gives lasting proper- 
 ties to the perfume. 
 
 PILLS. 
 
 Why is the maximum weight of pills of organic 
 matter about five grains, while that of pills of 
 inorganic matter can be as high as nine or ten 
 grains? The size sometimes governs the possible 
 weight of a pill, and inorganic matter is usually less 
 bulky than organic matter. 
 
 Why is it best to triturate potent substances with 
 sugar of milk or other inert substance before mixing 
 
rREPARATIONS. 51 
 
 them with the other ingredients of the pill mass? By 
 so doing the potent substance is more thoroughly 
 distributed throughout the mass. 
 
 Why is a mortar and pestle better than a pill-tile 
 and spatula in making a pill mass? More pressure 
 can be used in mixing the ingredients, the heat gen- 
 erated softens the mass, and there is less danger of 
 getting in too much excipient. 
 
 Why are simple syrup, syxup of acacia, mucilage 
 of acacia, and glucose objectionable as general pill 
 excipients? Pills made with any one of them soon 
 become so hard that they pass through the ahmentary 
 canal without dissolving. The addition of a Uttle 
 glycerin which is hygroscopic overcomes this objec- 
 tion. 
 
 Why is glycerin objectionable as a pill excipient 
 when used alone? It is hygroscopic, and pills made 
 with it may absorb moisture and become too soft. 
 
 Why is soap a good excipient for resinous sub- 
 stances? It not only makes a good mass, but prob- 
 ably aids the emulsification and absorption of the 
 resin in the alimentary canal. 
 
 Why is sulphuric acid sometimes used in pills of 
 quinine? It reduces the bulk by converting the 
 quinine into the bisulphate. 
 
 Why should soap not be used with metallic salts? 
 It combines with many of them, forming oleates or 
 hydroxides if strongly alkaline. 
 
 Why should tragacanth be used only in small 
 amounts as a pill excipient? If used in large quan- 
 
52 WHYS IN PHARMACY. 
 
 titles it makes the mass so spongy that the pills are 
 made with great difficulty. 
 
 Why cannot potassium permanganate, silver ni- 
 trate, and gold chloride be massed with common 
 excipients? Because they are reduced. Some sub- 
 stance that will not be acted upon must be used. 
 
 Why are fibrous drugs frequently useful as pill 
 excipients? They are absorbents and serve to bind 
 the mass together, as well as to aid disintegration of 
 the pill. 
 
 Why should althsea and tragacanth be used spar- 
 ingly as pill excipients? They contain mucilage and 
 are apt to make the pills hard. They also make the 
 pill mass spongy and difficult to roll. 
 
 Why is lycopodium a good dusting powder? It 
 is a fine powder, tasteless, repels water, and does 
 not become sticky; moreover, it protects the pill. 
 
 Why is arrowroot or potato-starch better than 
 corn-starch as a dusting powder? Corn-starch tends 
 to stick together more than either of the other two. 
 
 Why must pills be kept in motion after being 
 dipped in a hot solution of gelatin to coat them? 
 If they were not kept in motion the coating would 
 run to the lower side of the pill, forming a lump. 
 
 Why should glycerin not be used as a part of the 
 pill excipient if the pill is to be coated with gelatin? 
 Glycerin does not dry out and it dissolves the gelatin. 
 
 Why may either keratin or salol be used in coating 
 pills when it is desired that the pill should not dis- 
 solve in the stomach? Both of these substances 
 
PREPARATIONS. 53 
 
 do not dissolve in the acid contents of the gastric 
 juice, but do in the alkahne fluids of the intes- 
 tine. 
 
 Why is dried sulphate of iron used in preference 
 to the crystalline in making pills of aloes and 
 iron? The dried sulphate is less bulky. 
 
 Why does the mixture of salts with glycerin and 
 water in pills of carbonate of iron get softer on tritu- 
 rating? It is due to the water of crystallization 
 which is liberated when the reaction takes place. 
 
 Why is the crystalline sulphate of iron used in 
 Blaud's pills in preference to the dried sulphate? 
 It dissolves more rapidly and consequently reacts 
 more quickly. 
 
 Why do pills of carbonate of iron change color? 
 Ferric oxide is formed, which gives them a reddish 
 color. 
 
 Why is reduced iron used in pills of iodide of 
 iron? It is finer and reacts more readily. 
 
 Why is an excess of iron used in pills of iodide of 
 iron? To prevent subsequent liberation of iodine 
 by oxidation. 
 
 Why are iron and iodine triturated together until 
 free from red color? This shows that all of the 
 iodine has united with the iron. 
 
 Why are pills of iodide of iron coated? So as to 
 prevent oxidation by the air and the liberation of 
 iodine. 
 
 Why are pills of iodine best made with starch? 
 Starch forms a compound with iodine, which is 
 
54 WHYS IN PHARMACY. 
 
 easily broken up in the alimentary canal, giving 
 the action of iodine. 
 
 Why are pills of phosphorus coated? To prevent 
 oxidation. 
 
 Why is chloroform used in pills of phosphorus? 
 Chloroform is a good solvent of phosphorus, and 
 the phosphorus is thereby more evenly distributed 
 through the pill mass. The vapor tends to prevent 
 oxidation. 
 
 POWDERS. 
 
 Why are not all solids suitable for administra- 
 tion in the form of powders? Because some are 
 hygroscopic, some are efflorescent, some are changed 
 by the air, and some would have to be given in 
 too large doses. Many of them would not have 
 the effect desired if given in a concentrated form. 
 Many of the very soluble salts are irritating to the 
 alimentary canal. 
 
 Why are some solids best given in the form of 
 powders? Because in such form they may act as 
 mechanical protectives, such as bismuth subnitrate, 
 for instance. Some are more pleasant and con- 
 venient to take in this way. 
 
 Why is less attention to incompatibilities necessary 
 in dispensing medicines in the form of powders? 
 Because when substances are kept dry and not 
 heated there is but little danger of chemical change. 
 
 Why is it better to dampen such substances as 
 resin, acetanilid, and salol with alcohol when they 
 
PREPARATIONS. 55 
 
 are to be powdered? Because substances of this 
 nature become more or less electrified by the rub- 
 bing, and adhere to the utensils or are scattered 
 about, and alcohol overcomes this tendencv. 
 
 Why are compound powders directed to be passed 
 through a sieve? This breaks up all the lumps and 
 mixes the powders more thoroughly. 
 
 Why should powders for insufflation be passed 
 through a bolting-cloth? This overcomes the ten- 
 dency to making a dense powder by trituration, 
 leaving it light and fluffy. 
 
 Why is syrup better than water as a vehicle for 
 the administration of powders? It is more dense 
 and keeps the powder suspended better. 
 
 Why is the cachet or wafer better than a gelatin 
 capsule for the administration of powders? Because 
 the cachet when wet is slippery and assumes any 
 form. In the stomach the cachet dissolves more 
 quickly and does not produce the sensation of 
 weight. 
 
 Why should potassium chlorate not be triturated 
 with organic matter? Because there is danger of 
 explosion. 
 
 Why should camphor be dampened with alcohol 
 before being powdered? Because it can then be 
 reduced to an almost impalpable powder; when 
 rubbed alone it cannot. 
 
 Why is acacia used in compound chalk powder? 
 This powder is used only in making chalk mixture, 
 and the acacia helps to suspend the chalk. 
 
56 WHYS IN PHARMACY. 
 
 Why is prepared chalk better than precipitated 
 calcium carbonate in making compound chalk 
 powder? It is not crystalline and is smoother, less 
 gritty. 
 
 Why is the mixture of sodium bicarbonate and 
 Rochehe salt wrapped separately from the tartaric 
 acid in Seidlitz powders? If ah the ingredients are 
 mixed together moisture from the air is absorbed 
 and chemical reaction takes place. Besides, if the 
 mixture of the three ingredients is put into water 
 effervescence is completed before all of the Rochelle 
 salt is dissolved. 
 
 Why are two different colored papers used in 
 wrapping Seidlitz powders? Because if only one 
 colored paper were used there would be danger of 
 two packages of the salt mixture or two of the 
 acid being wrapped together. 
 
 Why are the small wooden measures used for 
 measuring Seidlitz powders objectionable? Because 
 the amount the measure holds varies with the atmos- 
 phere and with pressure, and the measure gets worn 
 so that it holds less than it should. 
 
 Why, in making compound licorice powder, is 
 the oil of fennel mixed with the sugar rather than 
 with the senna? Because it can be more thoroughly 
 and readily distributed through the powder. 
 
 Why is the oil of fennel preferred to the powdered 
 fennel in compound licorice powder? Because the 
 preparation keeps better. 
 
 Why is sugar of milk in as coarse powder as No. 30 
 
PREPARATIONS. 57 
 
 used in making Dover's powder? Because in that 
 condition it is gritty, and, in powdering it, it cuts up 
 and divides the ipecac and opium more completely. 
 Why is it better, in making compound rhubarb 
 powder, to mix the rhubarb and ginger first, and 
 then incorporate the magnesia? The magnesia can 
 be more readily and thoroughly mixed than by 
 mixing the powders promiscuously. 
 
 GRANULAR EFFERVESCING POWDERS. 
 
 Why are effervescing powders frequently preferred 
 to non-effervescing powders? Because the presence 
 of carbon dioxide makes the mixture more palatable. 
 
 AVhy is the method of granulating by heat prefer- 
 able to that of dampening with alcohol? Because 
 there is less danger of chemical reaction during the 
 process of manufacture, and because, too, it requires 
 a much shorter time for drying. 
 
 Why is citric acid used instead of tartaric acid in 
 granulating with heat? Because citric acid contains 
 one molecule of water of crystallization, which is 
 liberated by heat and makes a mass of the in- 
 gredients. 
 
 Why, in granulating by heat and passing through 
 a sieve, must the manipulations be carried on quickly? 
 Because the water of crystallization is soon driven 
 off and the mixture loses the form of a soft mass. 
 
 Why should the mixture of sodium bicarbonate 
 and acid not be triturated in a mortar? Because 
 
58 WHYS IN PHARMACY. 
 
 hard pressure induces chemical reaction and the 
 consequent liberation of carbon dioxide. 
 
 Why is it better to mix sugar and sodium bicar- 
 bonate together before mixing with the acid? The 
 tendency to reaction is lessened. 
 
 Why must strong alcohol be used in granulating 
 with alcohol? Because the water that the alcohol 
 contains is left after the alcohol is evaporated, and 
 the acid and sodium bicarbonate react in the presence 
 of water. 
 
 Why must salts containing a large amount of 
 water of crystallization be partially dried before 
 granulating? Because frequently the water is liber- 
 ated and induces the chemical reaction. 
 
 Why must well-tinned sieves be used in granulat- 
 ing powders? Because the acid would attack the 
 iron or copper and the product would be dis- 
 colored. 
 
 Why must granular effervescing powders be kept 
 in well-closed containers? Because they are hygro- 
 scopic, and, absorbing moisture, chemical reaction 
 takes place. 
 
 Why is a temperature of not over 54° C. best for 
 drying effervescing powders? Powders thus dried 
 keep better. 
 
 Why does the U. S. P. give the title Caffeina 
 Citrata Effervescens instead of Caffeinse Citras 
 Effervescens? Because citric acid and caffeine are 
 probably not combined, simply mixed. 
 
 Why is citric acid used in slight excess in the 
 
PREPARATIONS. 59 
 
 formula for effervescing lithium citrate? It gives a 
 more pleasant taste to the product. 
 
 Why does the U. S. P. (1890) direct the drying 
 of effervescing magnesium citrate at a temperature 
 not above 30° C? Because a heat above that 
 causes the formation of the less soluble normal 
 magnesium citrate. 
 
 RESINS. 
 
 Why is hydrochloric acid used in making resin 
 of mandrake? It renders the resin less soluble in 
 water. 
 
 Why does the resin of mandrake of commerce 
 differ in color? Because other substances than 
 hydrochloric acid are used in precipitating it, and 
 these influence the color. 
 
 SPIRITS. 
 
 Why, in making the spirit of nitrous ether, is the 
 ethyl nitrite washed with water? To remove any 
 alcohol that may have distilled over. 
 
 Why, in making the spirit of nitrous ether, are 
 sodium and potassium carbonates used? Sodium 
 carbonate is used to neutralize the acid and aid its 
 removal from the distillate, and the potassium 
 carbonate is used to remove the last part of water. 
 
 Why should the spirit of nitrous ether be kept 
 in the dark? Light tends to decompose the ethyl 
 nitrite, forming alcohol and nitrous and nitric acids. 
 
60 WHYS IN PHARMACY. 
 
 Why is sulphuric acid used in estimating spirit 
 of nitrous ether? To hberate nitrous and hydriodic 
 acids so that the latter will decompose the former. 
 
 Why, in making spirit of ammonia, should alcohol 
 recently distilled and kept in glass vessels be used? 
 Alcohol is generally kept in barrels for a time, and 
 it absorbs organic matter which is colored by 
 ammonia; by using the recently distilled article this 
 coloration is avoided. 
 
 Why is the ammonia water heated to a tem- 
 perature not exceeding 60° C. in making spirit of 
 ammonia? A higher temperature would drive over 
 more water and thus dilute the alcohol. 
 
 Why is ammonia water used in making aromatic 
 spirit of ammonia? It is used for its therapeutic 
 effect and also to convert the ammonium bicar- 
 bonate into the normal carbonate, so that it will 
 be soluble in alcohol. 
 
 Why does the U. S. P. direct ammonium carbonate 
 in '' translucent pieces"? So as to get the requisite 
 amount of salt. Opaque pieces have lost ammonia 
 and carbon dioxide and consist of ammonium 
 bicarbonate. 
 
 Why is aromatic spirit of ammonia set aside for 
 twelve hours before being filtered? In order to give 
 time for the ammonium liydroxide to act on the bi- 
 carbonate. 
 
 Why does aromatic spirit of ammonia turn dark 
 on keeping for some time? Alcohol frequently con- 
 tains some aldehyde and other impurities which 
 
PREPARATIONS. 61 
 
 are darkened by ammonia; then the gradual increase 
 in color is due to the action of ammonia on the oils. 
 
 Why should whisky be at least four years old? 
 So as to allow chemical changes to take place whereby 
 some of the objectionable impurities are changed, 
 and the acids combined with alcohols, forming 
 ethers and esters. 
 
 Why should spirit of nitroglycerin be kept in 
 cans rather than in bottles? Bottles are likely to 
 get broken and the spirit leak out. The alcohol, 
 being much more volatile than nitroglycerin, the 
 latter is left, and in concentrated condition may be 
 exploded. In case of such an accident, the U. S. P. 
 directs the use of potassium hydroxide to decompose 
 the nitroglycerin. 
 
 Why is peppermint herb used in making spirit 
 of peppermint? Chiefly to give color. 
 
 Why should spirits of peppermint and lemon be 
 protected from light? Light destroys the color. 
 
 Why is it better to wash the peppermint herb in 
 water before using in making spirit of peppermint? 
 Water takes out a yellow coloring matter so that 
 the spirit has a better appearance. 
 
 Why add the water '^ gradually" in making bay 
 rum (1890)? So that the formation of a permanent 
 milkiness may be avoided as far as possible. 
 
 Why is bay rum (1890) allowed to stand eight 
 days before filtering? To allow the mixture of 
 alcohol and water to dissolve as much of the oils 
 as it will, and also to let the excess of oils separate 
 
62 WHYS IN PHARMACY. 
 
 and form larger globules, making them more easy 
 to filter out. 
 
 Why is absolute alcohol used in making spirit of 
 phosphorus (1890)? It is a better solvent than 
 ordinary alcohol, which dissolves phosphorus but 
 shghtly. 
 
 SUPPOSITORIES. 
 
 Why is cacao butter a good suppository base? 
 Because it is solid at ordinary temperatures, liquid 
 at the temperature of the body, and is a bland, sooth- 
 ing substance. 
 
 Why, in hardening cacao butter suppositories, 
 must care be used not to get too much of the harden- 
 ing agent? Since the base does not dissolve in the 
 alimentary canal, but melts, the melting-point must 
 not be above the temperature of the body. 
 
 W^hy are hand-made suppositories preferable to 
 suppository shells? In the hand-made suppositories 
 the medicinal matter is mixed throughout the sup- 
 pository, while in the shells the medicinal matter is 
 not absorbed until the shell has been entirely melted, 
 and may be in such concentrated form as to be 
 irritating. 
 
 Why must a suppository mass not be too hot when 
 it is poured into molds? If it contains medicinal 
 matter insoluble in the melted base, the insoluble 
 matter will sink to the apex of the cone. 
 
 Wliy is a base of gelatin and glycerin sometimes 
 
PREPARATIONS. 63 
 
 preferred to cacao butter in making urethral and 
 nasal suppositories? Because it is less likely to break. 
 
 Why should gelatin not be used as a base for 
 ichthyol suppositories? Ichthyol makes gelatin in- 
 soluble. 
 
 Why are glycerin suppositories preserved in tight 
 vessels? Because they are sufficiently hygroscopic 
 to become liquid when exposed to the air. 
 
 Why are suppositories containing tannic acid best 
 made in the cold? Because a heat not much above 
 the temperature necessary for melting the base will 
 cause the acid to form tough, hard masses. 
 
 Why should iodoform suppositories not be made 
 with heat? The overheating of iodoform in cacao 
 butter causes it to form masses. 
 
 SYRUPS. 
 
 Why should an excess of sugar be avoided in mak- 
 ing syrups by heat? In cooling, the excess crystal- 
 lizes out and more besides, leaving a solution that 
 has been weakened sufficiently to be apt to fer- 
 ment. 
 
 Why do some persons claim that heat is objection- 
 able in making simple syrup? Continued heat 
 inverts sugar to some extent, making it more 
 likely to ferment. 
 
 Why does a syrup that has once fermented quickly 
 ferment again, even after it is boiled? (1) The 
 spores of the micro-organisms may not all have been 
 
64 WHYS IN PHARMACY. 
 
 killed; (2) the proportion of sugar has been dimin- 
 ished by fermentation; and (3) part of the sugar 
 has been inverted, in which condition it more readily 
 ferments. 
 
 Why does syrup of acacia undergo decomposition 
 more quickly than simple syrup? Because acacia 
 in water spoils quickly. The preparation keeps 
 better than when made by the previous formula. 
 
 Why does syrup of lemon spoil more quickly 
 than syrup of citric acid? Syrup of lemon, being 
 made from lemon juice, contains some albumin 
 which always tends to cause decomposition. 
 
 Why does syrup of citric acid sometimes acquire 
 a turpentine odor and taste? Oil of lemon changes 
 on exposure. 
 
 Why is syrup of citric acid slightly opalescent? 
 Tincture of lemon is used in making it, and the oil, 
 separated from the alcohol by the syrup, causes 
 the turbidity. 
 
 AVhy is althsea washed with cold water in making 
 syrup of althsea (1890)? To remove dust and im- 
 purities. 
 
 Why is althsea macerated with cold water instead 
 of hot? Hot water makes a preparation that is thick 
 and stringy. 
 
 Why are alcohol and glycerin used in syrup of 
 altha?a? They act as preservatives. 
 
 Why is magnesium carbonate used in making 
 syrup of orange? To aid the removal of finely pre- 
 cipitated matter. 
 
PREPARATIONS. 65 
 
 Why, in making syrup of calcium lactophosphate, 
 does the U. S. P. start with calcium carbonate in- 
 stead of calcium phosphate, since calcium phosphate 
 is ultimately formed? While calcium phosphate is 
 soluble in acids, it is much less readily soluble after 
 it has been dried. In following the official direc- 
 tions the calcium phosphate may be dissolved in the 
 nascent condition. The phosphoric acid is diluted 
 to prevent precipitation. 
 
 Why is syrup of lime boiled in a copper or tinned- 
 iron vessel instead of glass or porcelain? The hot 
 alkahne solution would be hable to attack the glass 
 or porcelain. 
 
 Why must syrup of lime be well protected from 
 the air? It absorbs carbon dioxide from the air, 
 forming calcium carbonate, which is precipitated. 
 
 Why is syrup of lime stronger than lime water? 
 Lime combines with sugar to form various saccharates 
 which are more soluble than calcium hydroxide, and 
 which, being loose combinations, are easily decom- 
 posed, thus acting as calcium hydroxide does. 
 
 Why is an excess of iron over iodine used in mak- 
 ing the syrup of iodide of iron? Because if an ex- 
 cess of iodine were used it could not be removed by 
 filtration as iron can be. The excess of iron also 
 aids reaction and prevents oxidation. 
 
 Why is the reaction more rapid after some ferrous 
 iodide has been formed in making syrup of iodide 
 of iron? Chemical reaction generates heat and heat 
 aids reaction. Also the ferrous iodide dissolves 
 
66 WHYS IN PHARMACY. 
 
 iodine and gets it into form so that it will react 
 more readily with iron. 
 
 Why is it necessary to check the reaction between 
 iron and iodine? Sometimes the heat generated is 
 sufficient to crack the vessel or to volatilize the 
 iodine. 
 
 Why, in making the syrup of iodide of iron, is 
 the mixture of iodine, iron, and water heated to 
 boiling before filtering? So as to complete the chemi- 
 cal reaction. 
 
 Why is sugar added to the solution of ferrous 
 iodide before filtering? Sugar has a reducing action 
 and tends to prevent the oxidation of ferrous iodide. 
 
 Why is hypophosphorous acid added to the syrup 
 iodide of iron? To prevent oxidation and liberation 
 of iodine. 
 
 Why does syrup iodide of iron become red? Iodine 
 is gradually liberated and dissolved. Sometimes cara- 
 melization of the sugar takes place. 
 
 Why should syrup of ferrous iodide be kept in 
 direct sunhght? Direct sunlight prevents or retards 
 the liberation of iodine and reduces it after it has 
 been liberated. 
 
 Why should bottles containing syrup of iodide of 
 iron be kept full? To avoid contact with air which 
 oxidizes it. 
 
 Why should the syrup of the phosphate of iron, 
 quinine, and strychnine be protected from hght? 
 Light gradually causes a chemical change in the iron, 
 resulting in a darkened preparation. 
 
PREPARATIONS. 67 
 
 Why is hypophosphorous acid used in syrup of 
 hypophosphites? It aids the solution of the hypo- 
 phosphites, particularly the calcium salt. It also 
 gives a more pleasant taste. 
 
 Why is potassium citrate used in compound syrup 
 of hypophosphites? To aid the solution of iron and 
 manganese hypophosphites. 
 
 Why is potassium citrate used in the syrup of 
 hypophospliites with iron (1890)? An alkali citrate 
 makes the ferrous lactate more soluble, and it 
 also prevents the precipitation of hypophosphite 
 of iron. 
 
 Why should syrup of hypophosphites with iron 
 (1890) be freshly made when wanted? It gradually 
 changes, becoming darker. 
 
 Why must calcium phosphate not be used to aid 
 filtration in making syrup of ipecac? Because it 
 would be dissolved by the acetic acid. 
 
 Why is acetic acid used in syrup of ipecac? To 
 convert the emetine into an acetate which is soluble. 
 
 Why is glycerin used in syrup of ipecac? To pre- 
 vent souring; the syrup soon spoils if not protected 
 by glycerin. 
 
 W^hy is sand used in making syrup of tar? To 
 divide the tar so that water can be mixed with it 
 better. 
 
 Why is the first water which is used in washing tar 
 thrown away in making syrup of tar? Tar generally 
 contains some pyroligneous acid and other impuri- 
 ties that are not wanted. 
 
68 WHYS IN PHARMACY. 
 
 Why is alcohol used in syrup of tar? For its 
 solvent effect. 
 
 Why is a wild cherry bark macerated for twenty- 
 four hours in making syrup of wild cherry? To allow 
 the ferment, emulsin, to act on the amygdalin, form- 
 ing hydrocyanic acid and benzaldehyde. 
 
 Why must the sugar be dissolved without heat in 
 making syrup of wild cherry? Heat would drive off 
 the hydrocyanic acid and benzaldehyde. 
 
 Why is potassium carbonate used in syrup of 
 rhubarb and aromatic syrup of rhubarb? It pre- 
 vents the precipitation of resinous matter by form- 
 ing a soluble compound with it. 
 
 Why, in making syrup of raspberries (1890), are 
 the raspberries allowed to stand until the filtered 
 juice mixes clear with half its volume of alcohol? 
 Raspberries contain a pectinous substance which, if 
 left in, tends to cause the decomposition of the 
 syrup. It is destroyed or precipitated by this fer- 
 mentation and a clear solution of the filtrate with 
 alcohol indicates that it has been removed. 
 
 Why is syrup of raspberries (1890) heated to boil- 
 ing? To precipitate any albuminous matter which 
 may be left in and to destroy ferments. 
 
 Why is the mixture of the ingredients of com- 
 pound syrup of sarsaparilla set aside for an hour 
 before filtering? To allow nearly complete precipi- 
 tation. 
 
 Why is the vinegar of squills heated to boiling in 
 making syrup of squills (1890)? The vinegar con- 
 
PREPARATIONS. 69 
 
 tains albuminous matter which is coagulated by heat 
 and can then be filtered out. Albuminous matter 
 tends to cause fermentation. 
 
 Why in making syrup of squills is the vinegar not 
 boiled and strained? It is not now necessary since 
 in making the vinegar the liquid is boiled and the 
 albumin removed. 
 
 Why must a metallic vessel not be used in making 
 syrup of squills? The acetic acid would attack the 
 vessel. 
 
 Why is talc used in making compound syrup of 
 squills? To aid the removal of the finely precipitated 
 inert matter. 
 
 Why is potassium carbonate used in compound 
 syrup of asarum, N. F.? To make soluble com- 
 pounds with the resin in the asarum and the coloring- 
 matter of the cochineal. 
 
 Why is citric acid used in syrup of calcium and 
 sodium hypophosphites, N. F.? To aid solution and 
 to give the preparation an acid taste. 
 
 Why is iodine added to the solution of ferrous 
 iodide in making syrup of iodide of calcium, N. F.? 
 To form the ferric iodide. 
 
 Why is the iron wanted in the ferric condition in 
 making syrup of calcium iodide, N. F.? So that the 
 reaction with calcium carbonate will be more com- 
 plete, there being formed ferric hydroxide, which is 
 precipitated, and calcium iodide, which is left in 
 solution. 
 
 Why is potassium citrate used in syrup of calcium 
 
70 WHYS IN PHARMACY. 
 
 lactophosphate with iron, N. F.? To aid the solution 
 of iron lactate. 
 
 Why is solution of potassium hydroxide used in 
 aromatic syrup of yerba santa? To prevent the pre- 
 cipitation of resinous matter by forming a soluble 
 compound. 
 
 Why is iodine added to ferrous iodide in making 
 syrup of citro-iodide of iron, N. F.? To convert the 
 ferrous iodide into the ferric iodide, that salt being 
 wanted. 
 
 Why is potassium citrate used in making syrup of 
 hypophosphite of iron, N. F.? Hypophosphite of 
 iron is only sparingly soluble in water, but readily 
 soluble in an aqueous solution of a citrate probably 
 forming a double compound. 
 
 Why is acetic acid used in syrup of sanguinaria, 
 N. F.? To prevent precipitation. 
 
 TINCTURES. 
 
 Why is glycerin used in making tinctures? To aid 
 in dissolving the active matter, particularly when 
 this is tannic acid, and to retard or prevent subse- 
 quent changes and precipitation. 
 
 Why is the period of maceration shorter in making 
 tinctures than in making fluid extracts? Because the 
 proportion of the menstruum to the drug is much 
 greater. 
 
 Why are some drugs put into the percolator with- 
 out previous dampening in making tinctures? Be- 
 
PREPARATIONS. 71 
 
 cause if they are first dampened they would pack too 
 tight in the percolator and the menstruum could not 
 pass through. 
 
 Why is evaporation not necessary in making tinc- 
 tures as it is in making fluid extracts? Because by 
 the time enough menstruum is used to get the re- 
 quired percolate the drug is exhausted. 
 
 Why should tinctures not be made from fluid ex- 
 tracts? Because the menstruums used in making 
 the two classes of preparations are not always identi- 
 cal, and not infrequently the activity of the drug 
 is modified by the heat necessary in making fluid 
 extracts. 
 
 Why do tinctures of a fresh herb vary both in 
 alcoholic strength and therapeutic value? Because 
 the amount of water present at different times 
 varies. 
 
 Why is the process of maceration sometimes pref- 
 erable to percolation? Some drugs are resinous and 
 of such nature that they cannot be percolated. 
 
 Why is tincture of arnica made by maceration and 
 expression? The flowers are bulky and less alcohol 
 is required than if they were percolated. 
 
 Why are tinctures of sweet orange-peel and lemon- 
 peel made by maceration ? The fresh peels are used 
 and it is difficult to get the peels in suitable form for 
 percolation. 
 
 Why is the sweet orange-peel deprived of its 
 inner white part in making the tincture? The white 
 part contains tannin and hesperidin, which make 
 
72 WHYS IN PHARMACY. 
 
 the preparation objectionable when dispensed with 
 iron. 
 
 Why is cinnamon used in compound tincture of 
 gambir? To aid filtration and give a more pleasant 
 taste. 
 
 Why is the tincture of ferric chloride set aside for 
 three months? So as to allow chemical reaction to 
 take place between the free acid and the alcohol, 
 which results in the formation of chloric ether and 
 other compounds which are supposed to have a 
 diuretic effect. One writer claims that the ether 
 is the result of action between ferric chloride and 
 alcohol, ferric hydroxide being precipitated; he also 
 claims that aldehyde, ferrous chloride and free hydro- 
 chloric acid are formed by action of ferric chloride 
 on alcohol. 
 
 Why should tincture of iron be protected from the 
 light? Light reduces it to the ferrous condition. 
 
 Why does a tincture of iron that is perfectly clear 
 when first made sometimes precipitate on standing? 
 A certain amount of free acid is necessary to prevent 
 the precipitation of an oxychloride of iron, and, as 
 the acid becomes used up in the chemical reaction 
 which slowly takes place, the oxysalt is precipi- 
 tated. 
 
 Why does the addition of glycerin to tincture of 
 ferric chloride increase the color? Glycerin, as well 
 as water, alcohol and other liquids, darkens the tinc- 
 ture on account of partial hydrolysis of ferric chlo- 
 ride into the hydroxide and hydrochloric acid. The 
 
PREPARATIONS. 73 
 
 ferric hydroxide remains dissolved in the acid solu- 
 tion. 
 
 Why is it advisable to use a high grade of alcohol 
 in making tincture of iodine? If the alcohol con- 
 tains aldehyde or the higher homologues the iodine 
 is changed more qucikly to hydriodic acid. 
 
 Why is it that a freshly-made tincture of iodine 
 (1890) gives a precipitate of iodine when an old one 
 may not? An old tincture frequently contains some 
 hydriodic acid which is gradually formed, and this 
 keeps the iodine in solution even in the presence of 
 water. Precipitation is prevented in the present 
 formula by potassium iodide. Potassium iodide also 
 aids solution. 
 
 Why in making tincture of ipecac and opium is 
 the tincture of deodorized opium evaporated to 800 
 grams instead of 900 cc, which with the 100 cc. of 
 fluid extract would make the 1000 cc. of finished 
 tincture? In evaporating a liquid it is rather more 
 convenient to evaporate to a given weight than to a 
 given volume and then by evaporating below 900 
 cc. the precipitate can be filtered out and the filter 
 washed without getting too much filtrate. 
 
 Why is talc used in making tincture of kino? To 
 aid filtration. 
 
 Why should tincture of kino be kept in small, well- 
 stoppered bottles? If not so kept it is likely to 
 gelatinize. Glycerin tends to prevent gelatinization. 
 The amount of kino is now reduced one half and 
 there is less danger of gelatinization. 
 
74 WHYS IN PHARMACY. 
 
 Why is sand used in making tincture of lactuca- 
 rium? To cut up the lactucarium and aid percolation. 
 
 Why is benzin used in tincture of lacucarium? To 
 remove lactucerin, which is an inert caoutchouc-hke 
 substance. 
 
 Why is musk first rubbed with water in making 
 tincture of musk? Water dissolves out more of the 
 extractive matter than alcohol. 
 
 Why is tincture of nux vomica made from the 
 extract? It gives a more uniform product, and is 
 more convenient. 
 
 Why, in making laudanum, is opium macerated 
 twelve hours with water before adding the alcohol? 
 Water is a good solvent for the active principles and 
 it disintegrates opium better than alcohol. 
 
 Why is benzin used in making tincture of deodor- 
 ized opium? To remove the odorous principle and the 
 narcotine. 
 
 Why must the aqueous opium extract and benzin 
 not be shaken hard in making deodorized tincture 
 of opium? If shaken vigorously an emulsion will 
 be produced which requires a long time for separa- 
 tion. 
 
 Why is boiling water used in making tincture of 
 quillaja? It dissolves out the saponin more readily 
 than an alcoholic menstruum and heat does not de- 
 compose it. 
 
 Why is potassium carbonate used in aqueous tinc- 
 ture of rhubarb (1890)? It is alkaline and prevents 
 the precipitation of resinous matter. 
 
PREPARATIONS. , 75 
 
 Why is acetic acid used in tincture of sanguinaria? 
 It aids the sokition of the sanguinarine and retards 
 or prevents precipitation. 
 
 Why should the oil be removed from the tincture 
 of strophanthus? The preparation is brighter in 
 appearance and is not so liable to cause vomiting 
 and diarrhoea when the oil has been removed. 
 
 Why is vanilla macerated with the menstruum 
 previous to pounding it with sugar in making tinc- 
 ture of vanilla? The maceration softens it so that 
 it can be more readily disintegrated by the sugar. 
 
 Why should the use of Fleming's tincture of 
 aconite be discouraged? The tincture representing 
 seventy per cent, of drug, the drug is not exhausted 
 in making the tincture; besides, this tincture is 
 much stronger than other tinctures, and its exist- 
 ence is not necessary in view of the existence of 
 the official fluid extract and tincture. 
 
 AVhy is ammonia used in making detannated tinc- 
 ture of cinchona? To form ferric hydroxide with 
 solution of ferric sulphate. 
 
 Why is ferric hydroxide better than solution of 
 ferric sulphate for removing tannin? Ferric hydrox- 
 ide combines with tannin to form an insoluble com- 
 pound, which, with the excess of ferric hydroxide, 
 can be removed by filtration. Ferric sulphate forms 
 a soluble compound with tannin, which, with the 
 excess of iron salt, cannot be removed by filtra- 
 tion. 
 
 Why, in making ethereal tincture of iron, is the 
 
76 WHYS IN PHARMACY. 
 
 mixture of alcohol, ether, and solution of ferric 
 chloride placed in direct sunlight? Light reduces 
 the iron to the ferrous condition, and at the same 
 time other changes take place resulting in the forma- 
 tion of chloric ether. 
 
 Why is ethereal tincture of iron put into a shady 
 place after being decolorized? Partial oxidation 
 results and the mixture contains ferrous and ferric 
 iron. 
 
 Why does a deposit form in the tincture of citro- 
 chloride of iron? Because the alcohol throws the 
 sodium chloride out of solution. 
 
 Why is potassium carbonate used in making com- 
 pound tincture of guaiac? To prevent precipitation 
 of resinous matter, the alkali forming a somewhat 
 soluble compound with it. 
 
 Why is potassium iodide used in Churchiirs tinc- 
 ture of iodine? To help keep the iodine in solution, 
 as water precipitates it from alcoholic solution. 
 
 Why are sodium thiosulphate and ammonia water 
 used in decolorized tincture of iodine? They de- 
 colorize iodine by reducing it chiefly to the iodide 
 of sodium and iodide of ammonium. There is also 
 a little iodate formed. 
 
 Why put decolorized tincture of iodine into a cool 
 place before filtering? To aid the precipitation of 
 sodium tetrathionate. 
 
 Why should the use of decolorized tincture of 
 iodine be discouraged? The title of the tincture is 
 misleading, as in reality the preparation is a tincture 
 
PREPARATIONS. i i 
 
 of the iodides of sodium and ammonium and does 
 not have the physiological effect of iodine. 
 
 TROCHES, 
 
 Why is tragacanth preferable to acacia in making 
 lozenges? It makes a more tenacious mass. 
 
 Why is a gelatin base objectionable in making 
 lozenges containing tannic acid? The tannic acid com- 
 bines with gelatin to form an insoluble compound. 
 
 AVhy are fine powders not suited for making com- 
 pressed tablets? Air gets in between the particles 
 and is held there so that the particles do not stick 
 together. A granulated powder works much better. 
 
 Why should tablet triturate molds not be washed 
 with hot water? They are generally made of rubber 
 and heat warps them. 
 
 Why is starch used in making compressed tablets? 
 Starch may be used as a dilutent and it also has the 
 property of making the tablet disintegrate more 
 quickly. 
 
 OINTMENTS. 
 
 Why should an ointment base be free from ran- 
 cidity? Because of the odor and because the free 
 acid is frequently irritating and may sometimes 
 cause chemical reaction. 
 
 Why is yellow wax better than white wax for 
 ointments? In bleaching wax it undergoes a change 
 which makes it more liable to become rancid. 
 
78 WHYS IN PHARMACY. 
 
 Why is hydrous wool-fat a good ointment base 
 in certain cases? Because it is readily absorbed, 
 carrying with it the medicinal agent, and it can be 
 mixed with a large percentage of water without 
 losing its ointment properties. Moreover, it fre- 
 quently aids in making an ointment when liquids 
 are called for which are not miscible with the pre- 
 scribed base. 
 
 Why does the U. S. P. allow as much as 30 per 
 cent, of water in hydrous wool-fat? Anhydrous wool- 
 fat is very tough and sticky, and the presence of 30 
 per cent, of water gives it the proper consistency for 
 an ointment base. 
 
 Why is wool-fat recognized in addition to the 
 hydrous wool-fat? The anhydrous fat is good for 
 ointments containing water, and also good in cases 
 where water is objectionable. 
 
 Why is lard a good ointment base? It is cheap, 
 fairly readily absorbed, and will mix with some 
 water. 
 
 Why is petrolatum a good ointment base in cer- 
 tain cases? It is cheap, is not readily absorbed, and 
 consequently acts as a protective, and does not be- 
 come rancid. 
 
 Why is glycerite of starch a good ointment base in 
 certain cases? Because it is not greasy and can be 
 easily washed off. 
 
 Why should medicinal agents be mixed with a 
 small portion of the base first? Because they can 
 be nmcli more readily and thoroughly mixed. 
 
PREPARATIONS. 79 
 
 Why should a solid be in an impalpable powder 
 before mixing with the ointment base? Because it is 
 almost impossible to powder after mixing. 
 
 Why are moderately soluble salts better rubbed 
 with a little oil rather than with water in making 
 ointments? If dissolved in water the latter will 
 evaporate and the salts will crystallize and possibly 
 become irritating. 
 
 Why should ointments be stirred when cooling? 
 Because the ingredients having the higher melting- 
 points will sometimes solidify first, making a gran- 
 ular ointment. 
 
 Why is paraffin an objectionable substitute for 
 wax in ointments? Because it is liable to make the 
 ointment granular. 
 
 Why should agents that are likely to react with one 
 another in an ointment be rubbed separately with 
 some of the greasy base and then mixed? They are 
 protected by the base so that they do not come in 
 sufficiently intimate contact to react. 
 
 Why should the temperature not rise above 60° C. 
 in making benzoated lard? A higher temperature 
 volatilizes to a greater or less extent the benzoic acid 
 and volatile oil. 
 
 Why should an iron spatula not be used in making 
 tannic-acid ointment? Tannic acid attacks iron 
 forming a little tannate of iron, which gives a dark- 
 ened ointment. If the spatula is first smeared with 
 the fatty base there is but little danger. 
 
 Why should heat not be used in making ointment 
 
80 WHYS IN PHARMACY. 
 
 of tannic acid? If the mixture is heated only a 
 little above the melting-point of lard the acid be- 
 comes sticky and forms tough masses that cannot 
 be distributed through the base. The glycerin re- 
 lieves this trouble. 
 
 Why should a horn spatula be used in making an 
 ointment containing salicylic acid? If an iron one 
 were used the iron might be attacked slightly, caus- 
 ing a pinkish color due to the formation of salicylate 
 of iron. 
 
 Why is rose water used in cold cream instead of 
 enough oil of rose to perfume? Water makes the 
 ointment more soft and creamy. 
 
 Why is it better to stir rose-water ointment for 
 some time? The longer it is stirred the whiter it is. 
 
 Why is borax used in cold cream? To give a 
 whiter and more creamy preparation. 
 
 Why is borax in cold cream sometimes objection- 
 able? Because it is alkaline and reacts with some 
 of the agents that are sometimes used with the 
 ointment. 
 
 Why must the melted mixture of lead plaster and 
 olive oil be partly cooled before adding the oil of 
 lavender in making diachylon ointment? The oil of 
 lavender would otherwise be volatilized. 
 
 AVhy is oleate of mercury used in making mer- 
 curial ointment? Because it is a good agent for 
 extinguishing mercury. 
 
 Why should mercurial ointment be kept in a cool 
 place? If it is warmed the mercvuy will separate. 
 
PREPARATIONS. 81 
 
 Why is the term '^blue ointment" now apphed to 
 the diluted mercurial ointment? Many customers 
 buy blue ointment to be used without the physician's 
 directions^ and in many cases the fifty per cent, 
 ointment is too strong. 
 
 Why do samples of citrine ointment vary in color 
 and consistency? Because of the variation of heat 
 used, and also on account of lard being frequently 
 adulterated. This does not always explain the reason 
 for variation, however, as samples are not always the 
 same even when made with the same ingredients and 
 at the same temperature. 
 
 Why should a metallic spatula be avoided in 
 handling citrine ointment? The ointment is acid 
 and attacks iron. 
 
 Why does citrine ointment sometimes become dark 
 colored when it is mixed with an alkali? Because 
 the mercury has been partly reduced to the mercurous 
 condition and the alkali causes the black oxide to be 
 formed. 
 
 Why does ointment of red oxide of mercury (1890) 
 become discolored? The base becomes rancid and 
 slowly reduces the mercury. 
 
 Why is lanolin better for making ointment of the 
 oxides of mercury than simple ointment? The mer- 
 cury oxides are not so readily reduced. 
 
 Why should heat not be used in making ointment 
 of iodoform? Heat causes iodoform to cake into 
 masses. 
 
 Why is potassium iodide used in ointment of 
 
82 WHYS IN PHARMACY. 
 
 iodine? Iodine cannot be reduced to an impalpable 
 powder, but it is very soluble in an aqueous solution 
 of potassium iodide, and this solution can be inti- 
 mately mixed with the base. 
 
 Why is water used in ointment of potassium iodide? 
 Potassium iodide is difficult to powder, but is very 
 soluble in water, and in solution can be more thor- 
 oughly mixed with the base. 
 
 Why is potassium carbonate used in making oint- 
 ment of potassium iodide? Free-fat acids that are 
 in lard when a little rancid liberate iodine, coloring 
 the ointment. Potassium carbonate prevents this. 
 
 Why is lanolin better than lard for ointment of 
 zinc oxide? The ointment is not so liable to become 
 granular. * 
 
 WINES- 
 
 Why is white wine used in preference to red wine 
 in making medicinal wines? It contains less tannin 
 and consequently has fewer incompatibilities. 
 
 Why is wine fortified with alcohol in making 
 medicinal wines? To make the preparations more 
 permanent. 
 
 Why is ferric hydroxide objectionable as a detan- 
 nating agent for wine? Wine contains potassium 
 acid tartrate, and this dissolves a little iron. 
 
CHEMICALS. 
 
 ACIDS. 
 
 Why is dilute acetic acid preferred to vinegar in 
 making pharmaceutical preparations? It is stronger, 
 more uniform in strength, free from color, and prepa- 
 rations made with it keep better. 
 
 Why was acetic acid, sp. gr. 1.04 (twenty-nine 
 per cent.), called ''No. 8"? It was formerly used 
 in the proportion of one part of acid to eight of water 
 in making dilute acid. 
 
 Why should bottles containing acetic acid not be 
 stoppered with rubber? The acid is likely to become 
 contaminated with substances used in the vulcan- 
 izing of the rubber. 
 
 Why is litmus not a good indicator in estimating 
 acetic acid in a liquid by means of a standard alkali 
 solution? Acetates though normal in composition 
 are alkaline to litmus, thus producing a lower result 
 than is correct. Phenolphthalein is better for all 
 organic acids. 
 
 Why in making acetic acid is distillation of wood 
 
 carried on slowly at a temperature below 218° C? 
 
 83 
 
84 WHYS IN PHARMACY. 
 
 The yield of acid is larger, the distillate contains 
 less empyreumatic matter, and the charcoal is better. 
 
 Why can not the determination of the specific 
 gravity of acetic acid be relied on as a means of de- 
 termining its strength? The specific gravity in- 
 creases until the acid is about seventy-seven per 
 cent, strong; then it remains about constant until 
 the acid is about eighty per cent, when the specific 
 gravity begins to decrease. Acetic acid of ninety- 
 nine per cent, has about the same specific gravity 
 as that of forty-six per cent. 
 
 Why does the odor of benzoic acid vary? Because 
 it is obtained from different sources and retains to 
 some extent the odor of the substance from which 
 obtained. 
 
 Why is hydrochloric acid better than sulphuric 
 acid in making boric acid from borax? Sodium 
 chloride is more easily washed out than sodium 
 sulphate, and it is said that under certain conditions 
 sulphuric acid combines with boric acid. More crys- 
 tallizations are necessary to purify the acid when 
 sulphuric acid is used. Sodium nitrate is more 
 readily washed out than the sulphate or chloride. 
 
 Why is the juice of lemons boiled in making citric 
 acid? Heat coagulates albuminous matter so that 
 it can be removed by filtration. 
 
 Why does the U. S. P. allow a little sulphuric acid 
 as an impurity in citric acid? Excess of sulphuric 
 acid is added to the calcium citrate to prevent the 
 formation of calcium-acid citrate which would hinder 
 
CHEMIC.VLS. 85 
 
 crystallization. Citric acid crystallizes better in the 
 presence of a little sulphuric acid. 
 
 Why is lead sometimes an impurity in citric acid? 
 The acid is usually crystallized in lead vats and dis- 
 solves a little metal. 
 
 Why is potassium hypophosphite used in making 
 dilute hydriodic acid? Hydriodic acid is oxidized 
 by air, liberating iodine, and potassium hypophos- 
 phite or hypophosphorous acid reduces it again. 
 
 Why is alcohol used in making dilute hydriodic 
 acid? To cause the more complete precipitation of 
 cream of tartar formed by the chemical reaction. 
 
 Why is the mixture of ingredients in hydriodic 
 acid set aside in ice water before filtering? To pre- 
 cipitate the cream of tartar. 
 
 Why in making dilute hydriodic acid is the filter 
 washed with dilute alcohol instead of water? Dilute 
 alcohol does not dissolve cream of tartar as water 
 does. 
 
 Why in making dilute hydriodic acid should the 
 filter be washed until the filtrate does not give a 
 turbidity with silver-nitrate solution? Absence of 
 turbidity shows that the hydriodic acid has been 
 all washed into the filtrate which is the part 
 used. 
 
 Why is arsenic frequently an impurity in hydro- 
 chloric acid? Sulphuric acid, which is used in mak- 
 ing hydrochloric acid, is often contaminated, arsenic 
 occurring in the iron pyrites from which sulphuric 
 acid is made. 
 
86 WHYS IN PHARMACY. 
 
 Why is commercial hydrochloric acid colored red? 
 The color is due to impurities, such as iron and 
 organic matter. 
 
 Why does concentrated hydrochloric acid give rise 
 to white fumes when exposed to air? These are due 
 largely to the formation of ammonium chloride by 
 combination with the ammonia of the air. 
 
 Why is the neck of the retort directed upward in 
 making dilute hydrocyanic acid (1890)? There is 
 some liability of sulphuric acid being carried over 
 and this arrangement is to lessen that liability. 
 
 Why does the U. S. P. give the method of making 
 dilute hydrocyanic acid from silver cyanide instead 
 of from potassium ferrocyanide? Hydrocyanic acid 
 does not keep well and can be made up extempo- 
 raneously from silver cyanide without having to assay 
 it, although this method is more expensive. 
 
 Why should the use of Scheele's hydrocyanic acid 
 be discouraged? It is two and one half times as 
 strong as the official acid, does not keep as well, and 
 is more variable and less reliable. 
 
 Why should dilute hydrocyanic acid be kept in 
 small, dark, amber-colored, cork-stoppered bottles? 
 Light causes the formation of the dark-colored para- 
 cyanogen. Moreover, Squibb found by experiment 
 that the acid keeps better in cork-stoppered bottles, 
 probably because a cork fits tighter than a glass 
 stopper. 
 
 Why is diluted alcohol used in making dilute hypo- 
 phosphorous acid, N. F.? To make the potassium 
 
CHEMICALS. 87 
 
 bitartrate more insoluble so that the acid will be 
 purer. 
 
 Why is the mixture of solution of potassium hypo- 
 phosphite and of tartaric acid set aside in a cool 
 place for twelve hours in making dilute hypophos- 
 phorous acid? Because this increases the precipita- 
 tion of cream of tartar. 
 
 Why is zinc carbonate or calcium carbonate used 
 in making lactic acid by fermenting sugar? In order 
 to neutralize the acid, for in the presence of much 
 lactic acid some butyric acid is formed. 
 
 W^hy must the temperature of lactic acid fermen- 
 tation not be below about 20° C, or higher than 
 about 40° C? A temperature below 20° C. tends to 
 the formation of acetic acid, and one above 40° C. 
 to the formation of butyric acid. 
 
 Why is lactic acid neutralized w^ith zinc carbonate 
 in testing it for glycerin? The zinc lactate formed is 
 insoluble in the alcohol used to dissolve out the 
 glycerin. 
 
 Wliy is sodium nitrate better than potassium 
 nitrate in making nitric acid? It is cheaper, yields 
 more acid, and does it at a lower temperature. 
 
 Why does nitric acid sometimes have a red color? 
 The color is generally due to nitrogen tetroxide, 
 which is a decomposition product of nitric acid. 
 
 Why does nitric acid give a yellow color when ap- 
 plied to the skin? With albuminoid substances it 
 forms the yellow xanthoprotein. 
 
 Why in making dilute nitrohydrochloric acid does 
 
88 WHYS IN PHARMACY. 
 
 the U. S. p. direct that strong nitric and hydro- 
 chloric acids be mixed, and then this mixture dihited 
 with water, instead of mixing the dilute acids them- 
 selves? Chemical reaction takes place when the 
 strong acids are mixed, but it is questionable whether 
 it ensues when the dilute acids are used. 
 
 Why should nitrohydrochloric acid be kept in 
 bottles not more than half full? The formation and 
 giving off of gas may go on for some time, and 
 there is less danger of bursting the bottle when it is 
 not full. 
 
 Why should the temperature not go over 190° C. 
 in driving off nitric acid from phosphoric acid in 
 the process of making the latter? A higher heat 
 tends to form pyro- and meta-phosphoric acids. 
 
 Why does the blackening on the addition of silver 
 nitrate to phosphoric acid, or the turbidity on add- 
 ing mercuric chloride, indicate phosphorous acid? 
 Phosphorous acid reduces silver nitrate to the metallic 
 condition, and reduces mercuric chloride to insoluble 
 calomel. 
 
 Why should nitrohydrochloric acid be kept away 
 from heat and light? Nitrosyl chloride and chlorine 
 are both gases and light changes the former to ni- 
 trous and hydrochloric acids and the latter to hydro- 
 chloric acid. 
 
 Why in titrating phosphoric acid, does it take only 
 one half as much standard potassium-hydroxide solu- 
 tion to get the end reaction when methyl orange is 
 used as an indicator as when phenolphthalein is 
 
CHEMICALS. 89 
 
 employed? Phenolphthalein shows a neutral reac- 
 tion with K2HPO4, but alkaUne with K3PO4, while 
 methyl orange shows neutral with KH2PO4, and 
 alkaline with K2HPO4. 
 
 Why should glacial phosphoric acid be dissolved 
 in water without heat in making dilute metaphos- 
 phoric acid, N. F.? Because heat readily changes it 
 to pyro- and then orthophosphoric acid. Light and 
 exposure to air also change it. 
 
 Why is "natural" salicylic acid preferred to "syn- 
 thetic" acid by many physicians? The acid made 
 from phenol has sometimes been found to be con- 
 taminated with carbolic and creosotic acids, which 
 are more depressing and poisonous than salicylic 
 acid. Synthetic acid, however, can generally now 
 be relied upon for purity. 
 
 Why does salicylic acid sometimes have a pink 
 color? It is due to the presence of a red decom- 
 position product. 
 
 Why is sodium carbonate used in testing salicylic 
 acid for carbolic acid as an impurity? Sodium car- 
 bonate converts salicylic acid into sodium salicylate 
 which is insoluble in ether. Carbolic acid, remain- 
 ing unaffected by the sodium salt, can be removed 
 with ether. 
 
 Why does sulphuric acid so often contain arsenic? 
 The acid is largely made by roasting iron pyrites, 
 and the arsenic which occurs in the pyrites is vola- 
 tilized. 
 
 Why should sulphuric acid be poured into water 
 
90 WHYS IN PHARMACY. 
 
 and not water into the acid in mixing the two? 
 There is less heat and less steam generated and less 
 danger of accident. 
 
 Why does mixing sulphuric acid and water pro- 
 duce heat? It is said to be due to chemical reaction 
 and contraction. Hydrates of sulphuric acid are 
 formed. 
 
 Why does sulphuric acid when dropped on such 
 organic matter as wood blacken it? The acid ab- 
 stracts the elements of water and leaves carbon. 
 
 Why is lead so often an impurity in sulphuric 
 acid? The acid is concentrated in lead vats; a 
 little lead sulphate is formed and is dissolved by 
 concentrated acid but is precipitated when the acid 
 is diluted with water. 
 
 Why does the U. S. P. state that aromatic sul- 
 phuric acid should contain not less than twenty per 
 cent, of absolute acid when it directs that 111 cc. of 
 acid be used in making 1000 cc? Ill cc. of sul- 
 phuric acid weigh 202.686 grams and contain 187.484 
 grams of absolute acid. The specific gravity of 
 aromatic sulphuric acid is given as 0.933, making 
 1000 cc. weigh 933 grams. This gives about 20.09 
 per cent, by weight of acid. 
 
 Why does aromatic sulphuric acid gradually 
 darken on keeping? It is due to a slow reaction of 
 the acid with the aromatics. 
 
 Why does the addition of water to aromatic sul- 
 phuric acid cause a precipitate? Because the alcohol 
 
CHEMICALS. 91 
 
 is SO diluted that the oil of cinnamon and the resin of 
 ginger are no longer soluble. 
 
 Why is charcoal preferred to copper in making 
 sulphurous acid? Theoretically none of the acid is 
 wasted with charcoal, carbon dioxide, sulphur di- 
 oxide and water being formed. In using copper 
 some of the acid combines with the copper to form 
 copper sulphate. 
 
 Why should there be a thistle or safety tube in 
 the sulphurous-acid generator? Because on remov- 
 ing the heat there is a contraction and the water 
 of the wash-bottle may be sucked back into the 
 generator, and coming in contact with the hot mix- 
 ture and retort will cause explosion or cracking of 
 the retort. 
 
 Why is sulphurous-acid gas washed in water? To 
 remove sulphuric acid which might be volatilized in 
 the process. 
 
 Why should the water employed to absorb sul- 
 phurous-acid gas be previously boiled? To remove 
 ammonia and free oxygen which water absorbs on 
 exposure to air and which cause the deterioration of 
 the acid. 
 
 Why does the gas from sulphurous acid blacken 
 mercurous-nitrate paper and not lead-acetate paper? 
 It reduces mercurous salts to metallic mercury, but 
 does not reduce lead salts. 
 
 Why should the name of the drug from which 
 tannic acid comes be incorporated in the title of the 
 axiid? Tannic acid from different sources has different 
 
92 WHYS IN PHARMACY. 
 
 properties, as for instance, tannic acid from nutgalls 
 gives a blue-black with ferric salts while the acid 
 from oak-bark gives a green-black. 
 
 INORGANIC COMPOUNDS. 
 
 Why is it better in making dried alum to let it 
 thoroughly effloresce at a temperature below 80° C. 
 and then heat to drive off the remaining water 
 than it is to heat it to liquefaction as directed by 
 the U. S. P.? The product so obtained is lighter, 
 more porous, and less gritty. Stirring during the 
 heating makes it more dense. 
 
 Why is it necessary to have a decided excess of 
 sodium carbonate in making aluminum hydroxide, 
 and why pour the alum solution into the carbonate 
 solution slowly with constant stirring? In order to 
 decompose all of the aluminum sulphate and to have 
 no basic sulphate formed. 
 
 Why is sodium carbonate used instead of sodium 
 hydroxide in making aluminum hydroxide? Sodium 
 hydroxide combines with aluminum hydroxide to 
 form a soluble compound while the carbonate does 
 
 not. 
 
 Why are the solutions of alum and sodium car- 
 bonate heated just before mixing in making aluminum 
 hydroxide? Chemical reaction takes place better and 
 a more dense precipitate is formed which can be 
 washed readily. 
 
CHEMICALS. 93 
 
 Why is aluminum hydroxide dried at a tempera- 
 ture below 40° C? A temperature much above that 
 will drive off some water of hydration, forming some 
 aluminum oxide which is more gritty. 
 
 Why does a solution of alum effervesce when mixed 
 with a solution of a carbonate? Alum is a Httle 
 acid and aluminum hydroxide, not carbonate, is 
 formed, liberating carbon dioxide. 
 
 Why in making ammonium benzoate should the 
 solution of ammonium benzoate be kept alkaline 
 during the evaporation? The salt is easily decom- 
 posed by heat, and ammonia tends to prevent decom- 
 position. 
 
 Why does ammonium carbonate become white and 
 opaque on exposure to air? It loses ammonia and 
 carbon dioxide (the carbamate), leaving the bicar- 
 bonate. 
 
 Why does the U. S. P. direct the use of ammonia 
 water in testing ammonium iodide for bromide and 
 chloride as impurities? If an iodide, bromide, and 
 chloride are all present they are precipitated by silver 
 nitrate as silver compounds. Silver iodide is practi- 
 cally insoluble in ammonia water while the bromide 
 and chloride are soluble. The iodide can be filtered 
 out, and the adding of the nitric acid to the filtrate 
 precipitates the bromide and chloride. 
 
 Why is a slight excess of antimony oxide used in 
 making tartar emetic? So as to neutralize all of the 
 cream of tartar, an excess of which cannot be filtered 
 out as readily as an excess of antimony oxide. 
 
94 WHYS IN PHARMACY. 
 
 Why is sodium bicarbonate used in estimating 
 tartar emetic? Reaction takes place between the 
 iodine and tartar emetic, forming hydriodic acid, 
 which must be converted into a neutral salt or a 
 reverse action takes place. 
 
 Why is hydrochloric acid added to silver nitrate 
 in making molded silver nitrate? It forms a small 
 amount of silver chloride which makes the fused 
 sticks more tough and less brittle. 
 
 Why is care necessary in mixing silver oxide with 
 organic matter? It gives up its oxygen very readily, 
 forming explosive mixtures. 
 
 Why cannot sodium hydroxide be replaced by 
 ammonium hydroxide in making silver oxide? Am- 
 monia forms a soluble compound with silver oxide. 
 
 Why is sodium bicarbonate used in the official 
 method of estimating arsenic trioxide? It is used to 
 neutralize the hydriodic acid formed, for in an acid 
 solution a reverse reaction would take place, hydri- 
 odic acid and arsenic acid forming iodine and arsen- 
 ous acid. Sodium bicarbonate is preferable to the 
 normal carbonate or the hydroxide because the end 
 reaction with starch is more delicate. 
 
 Why is gold and sodium chloride recognized by 
 the U. S. P. instead of gold chloride? Gold chloride 
 keeps better when mixed with sodium chloride. 
 
 Why must bismuth subnitrate be boiled with 
 citric acid until the mixture will give a clear solu- 
 tion with ammonia water, in making bismuth citrate? 
 Ammonia forms a soluble compound with bisnmth 
 
CHEMICALS. 95 
 
 citrate, but not with the subnitrate. If a clear solu- 
 tion with ammonia is not obtained, bismuth sub- 
 nitrate is not all changed. 
 
 Why should a large excess of ammonia water be 
 avoided in making bismuth and ammonium citrate? 
 Heating bismuth citrate with a large excess of am- 
 monia water tends to form the insoluble bismuth 
 hydroxide. 
 
 Why is it customary in making bismuth subnitrate 
 to convert the bismuth nitrate into the carbonate 
 and then back into the nitrate? To get rid of 
 arsenic. 
 
 Why in making precipitated calcium carbonate 
 are solutions of calcium chloride and sodium car- 
 bonate hot wnen mixed? Heat makes the precipi- 
 tated calcium carbonate denser and more easily 
 washed free from the sodium chloride. 
 
 Why does lime produce heat when mixed with 
 water? Chemical reaction takes place, forming cal- 
 cium hydroxide. 
 
 Why does chlorinated lime become moist on ex- 
 posure to air? It contains calcium chloride, which 
 is hygroscopic. 
 
 Why should heat not exceed 25° C. in making 
 chlorinated lime? Heat above that causes the forma- 
 tion of calcium chlorate. 
 
 Why is not all of the chlorine in chlorinated lime 
 available? Part of it is combined as calcium chlo- 
 ride which is a stable compound and not decomposed 
 by dilute or weak acids as calcium hypochlorite is. 
 
96 WHYS IN PHARMACY. 
 
 Why is prepared chalk recognized by the U. S. P. 
 when the purer calcium carbonate is official? Pre- 
 pared chalk is less crystalline, smoother, softer, more 
 adhesive, and better for internal administration. 
 
 Why is starch used in making sulphurated lime? 
 It is not necessary, but aids in the reduction of the 
 sulphate. 
 
 Why, in the U. S. P. method of estimating sul- 
 phurated lime, should ammonia water give no color 
 when added to the filtrate from the mixture of sul- 
 phurated lime and copper sulphate? If the full 
 amount of sulphide is in the sulphurated lime all 
 of the copper will be precipitated and none will 
 pass into the filtrate. If copper passes into the 
 filtrate it will give a blue color when ammonia water 
 is added. 
 
 Why is nitric acid used to wash out sulphuric acid 
 from chromium trioxide? Nitric acid does not dis- 
 solve much of the chromium trioxide, does not cause 
 chemical reaction, and can itself be removed by 
 heating. 
 
 Why does the color of chromium trioxide vary? 
 On account of the presence or absence of sulphuric 
 acid, that which contains sulphuric acid having more 
 of a scarlet color. 
 
 Why should asbestos or glass-wool be used for filter- 
 ing solutions of chromium trioxide? Paper, cotton, 
 or anything capable of being oxidized would be 
 affected and the acid reduced. 
 
 Why is sodium bicarbonate used instead of sodium 
 
CHEMICALS. 97 
 
 carbonate in making saccharated ferrous carbonate? 
 The carbon dioxide which is liberated protects the 
 ferrous salt from oxidation to some extent. 
 
 Why is sodium bicarbonate dissolved in water 
 '^not exceeding 50° C. '' in making saccharated car- 
 bonate of iron? A higher temperature decomposes 
 the bicarbonate, driving off the carbon dioxide, which 
 is wanted to protect the ferrous salt. 
 
 Why is hot water used in washing ferrous car- 
 bonate in making saccharated carbonate of iron? 
 Hot water dissolves sodium sulphate better and is 
 free from absorbed oxygen which would otherwise 
 tend to oxidize the iron. 
 
 Why does the U. S. P. method of estimating 
 chloride of iron not always show all of the iron 
 present? The official method estimates only the 
 iron in the ferric condition. Ferrous iron does not 
 liberate iodine from potassium iodide. 
 
 Why is excess of citric acid to be avoided in making 
 scale citrate of iron? Acid keeps the salt tough and 
 sticky so that it adheres to the glass on which it is 
 spread and does not scale. 
 
 Why is the solution of citrate of iron evaporated 
 at a temperature below 60° C. in making citrate of 
 iron? A higher temperature causes a reduction of 
 the iron. 
 
 Why, in testing ferric citrate for citric acid, is the 
 filtrate heated with calcium chloride in order to get 
 a precipitate when heat usually tends to dissolve 
 salts? Calcium citrate is formed, and like many 
 
98 WHYS IN PHARMACY. 
 
 calcium salts it is less soluble in hot water than in 
 cold. 
 
 Why is ferric citrate preferred to citrate of iron and 
 ammonia in making pills? It is not as hygroscopic 
 and the pills retain their form better. 
 
 Why does the U. S. P. not give a chemical for- 
 mula for citrate of iron? Because the water of 
 hydration varies, although a formula might be given 
 with limits, since the Pharmacopoeia requires the 
 salt to contain a nearly definite amount of iron. 
 
 Why are some samples of iron and ammonium 
 citrate more hygroscopic than others? The larger 
 the amount of ammonium salt present the more 
 hygroscopic it is. 
 
 Why is one half of the tartaric acid neutralized 
 with ammonia and then the balance of the acid 
 added to this, in making iron and ammonium tar- 
 trate (1890)? This procedure makes ammonium bi- 
 tartrate, to which is added later the ferric hydroxide 
 forming a double compound. 
 
 Why should care be used not to get in an excess 
 of ammonia in making soluble citrate of iron and 
 quinine (1890)? Ammonia precipitates the quinine 
 but not the iron in the presence of ammonium citrate. 
 
 Why should citrate of iron and strychnine not be 
 prescribed in solution? According to Squibb a de- 
 composition takes place in a few hours and strych- 
 nine is precipitated, rendering the mixture dangerous. 
 
 Why is ferric-ammonium sulphate used by the 
 N. F. in making ferric hypophosphite, instead of oiw 
 
CHEMICALS. 99 
 
 of the more common iron salts? It is more nearly- 
 neutral and consequently will give a larger yield. 
 Moreover, in an acid solution ferric hypophosphite 
 changes to ferrous phosphate. 
 
 Why is sugar of milk added to the solution of fer- 
 rous iodide before evaporating in making saccha- 
 rated iodide of iron (1890)? To prevent oxidation 
 and the liberation of iodine. 
 
 Why is a heated mortar used in powdering the 
 residue of iodide of iron and milk sugar? The resi- 
 due is hygroscopic and the heated mortar tends to 
 prevent the absorption of moisture. 
 
 Why is reduced iron added to the ferrous iodide 
 in making saccharated iodide of iron (1890)? It 
 combines with any iodine that may be liberated from 
 the iodide by the air. 
 
 Why should a solution of ferric salt always be 
 poured into ammonia, and not ammonia into the 
 iron solution, in making ferric hydroxide? Because 
 by adding the iron to the ammonia the latter is in 
 excess and the ferric hydroxide is formed, while if 
 the ammonia is added to the iron the latter is in 
 excess and a basic salt is precipitated. 
 
 Why should solution of ferric sulphate and am- 
 monia be cold and well diluted before mixing, in 
 making ferric hydroxide? To prevent the formation 
 of a basic compound. Several oxyhydrates may be 
 formed, and the more basic the hydrate, the less 
 soluble it is in acids. 
 
 Why is ammonium hydroxide preferable to sodium 
 
100 WHYS IN PHARMACY. 
 
 hydroxide in making ferric hydroxide? Ammonium 
 sulphate and the excess of ammonium hydroxide are 
 more easily washed out than the corresponding so- 
 dium compounds. 
 
 Why is ferric hydroxide washed by decantation? 
 It is bulky and gelatinous, not readily washed on the 
 filter, and is less liable to become partially dry and 
 changed to oxide. 
 
 Why must the soluble phosphate and the soluble 
 pyrophosphate of iron be well protected from the 
 light? Light renders them darker and less soluble. 
 
 Why do some persons think that soluble phos- 
 phate of iron and soluble pyrophosphate of iron are 
 chemical compounds? Because, if they are mere 
 mixtures, any salts that would be present would not 
 give the green color; the color is therefore due to a 
 new compound. 
 
 Why does ferrous sulphate frequently contain a 
 little sulphuric acid? It is not so readily oxidized 
 when acid is present. 
 
 Why does the official method of estimating ferrous 
 sulphate not always estimate all of the iron present? 
 Ferrous sulphate generally contains some ferric iron, 
 and in the ferric condition iron does not reduce 
 potassium permanganate. 
 
 Why, in making dried sulphate of iron, is ferrous 
 sulphate allowed to effioresce at a temperature of 
 40° C. previous to heating on a water-bath? If 
 heated at once on the water-bath the salt would dis- 
 solve in its water of crystallization; it would be 
 
CHEMICALS. , '\ iJ^'\ XOV ,; '\ ; 
 
 much harder to drive off the water and the residue 
 would be more gritty and granular. 
 
 Why is not all the water removed in making dried 
 sulphate of iron? The high heat necessary to remove 
 all the water would probably cause more or less 
 decomposition of the salt. 
 
 Why is sulphuric acid used in granulating ferrous 
 sulphate? Ferrous sulphate almost always contains 
 some oxysalt which does not dissolve, and sulphuric 
 acid brings it into solution. 
 
 Why is alcohol used in making granulated ferrous 
 sulphate? It washes out the water and acid, dis- 
 solving the ferric salt without dissolving the ferrous. 
 The ferrous sulphate is dried in an atmosphere of 
 alcohol which prevents oxidation. 
 
 Why is granulated ferrous sulphate preferably dried 
 in the sunlight? As light has a reducing effect on 
 iron salts, there is less danger of oxidation of the 
 ferrous salt. 
 
 Why is reduced iron sometimes called '^iron by 
 hydrogen"? In making it hydrogen is passed over 
 red hot ferric oxide and combines with the oxgyen 
 leaving metallic iron. 
 
 Why is the current of hydrogen passed over the 
 iron even after it is all reduced? To prevent air 
 coming in contact with the iron while it is hot, in 
 which condition it would absorb oxygen. 
 
 Why does reduced iron frequently contain an 
 oxide? In making it, if a low red heat is used, the 
 oxide is not all decomposed, and if a higher heat is 
 
102 WHYS IN PHARMACY. 
 
 used a more dense and less desirable product is 
 formed. If the iron is left in a moist atmosphere it 
 absorbs oxygen. 
 
 Why is manganese dioxide sometimes added to 
 mercuric sulphate and sodium chloride before sub- 
 liming in making mercuric chloride? To prevent the 
 formation of mercurous chloride. 
 
 Why is it that an aqueous solution of mercuric 
 chloride is acid to litmus but becomes neutral on 
 adding sodium chloride? It may be on account of 
 forming a new double salt which is neutral. 
 
 Why should mercuric chloride, particularly when 
 in solution, be protected from the light? Light re- 
 duces it slowly to mercurous chloride. This is pre- 
 vented to some extent by the presence of an alkali 
 chloride. 
 
 Why does the commercial mercuric chloride not 
 always give a clear solution with water? It fre- 
 quently contains a little mercurous chloride. 
 
 Why is ammonia used in testing mercuric chloride 
 for arsenic as an impurity? The mercury and ar- 
 senic are first converted into the sulphides and the 
 arsenous sulphide forms the soluble ammonium sulph- 
 arsenite which is subsequently decomposed by hy- 
 drochloric acid, precipitating the arsenous sulphide. 
 
 Why is the condenser kept at a temperature near 
 that of the subliming point of mercuric chloride in 
 making mercuric chloride and considerably below that 
 of mercurous chloride in making mercurous chloride? 
 It is desirable to have mercuric chloride in the form 
 
CHEMICALS. 103 
 
 of masses and mercurous chloride in powder so that 
 they can be more easily distinguished. When the 
 temperature of the condenser is near the subliming- 
 point of a substance that substance will condense 
 in the form of a mass, while if the temperature of 
 the condenser is much below the subliming-point 
 the substance will condense as a powder. 
 
 Why is a jet of steam introduced into the receiv- 
 ing chamber in making calomel? It makes the calo- 
 mel fine and soft, and dissolves out any mercuric 
 chloride formed. 
 
 Why should calomel not be triturated hard? It is 
 decomposed slightly, forming metallic mercury which 
 darkens it, and mercuric chloride which makes it 
 more active. 
 
 Why does the color of calomel vary even when 
 pure? The finer the powder the more yellow it is. 
 
 Why should calomel be kept in amber-colored 
 bottles? Light slowly decomposes it, forming metal- 
 lic mercury and mercuric chloride. 
 
 Why is an excess of mercury used in making yel- 
 low iodide of mercury? Because if the nitric acid is 
 in excess some mercuric salt is formed. 
 
 Why should the nitric acid and metallic mercury be 
 kept cool in making the yellow iodide of mercury? 
 Heat tends to produce mercuric nitrate. 
 
 Why is a little nitric acid added to the watery 
 solution of mercurous nitrate in making yellow iodide 
 of mercury? To prevent the formation of a basic salt. 
 
 Why, in making this salt, is the solution of potas- 
 
104 WHYS IN PHARMACY. 
 
 sium iodide poured into the solution of mercurous 
 nitrate instead of the mercury into the iodide? If 
 the mercury is poured into the potassium iodide solu- 
 tion the latter is in excess at first, at least, and in this 
 condition decomposes the mercurous iodide which is 
 first formed, giving mercuric iodide and metallic 
 mercury. The mercuric iodide further combines 
 with potassium iodide to form a soluble double salt. 
 
 Why is it well to wash mercurous iodide with 
 alcohol? To dissolve out any mercuric iodide that 
 may be present. 
 
 Why must mercurous iodide be protected from 
 the light? Light decomposes it, forming mercuric 
 iodide and metallic mercury, the latter darkens it. 
 
 Why is much of the mercurous iodide green instead 
 of yellow? Because it contains some finely divided 
 metallic mercury. Mercury finely divided has a 
 bluish color, and this with the yellow gives a green. 
 
 Why does the U. S. P. direct the solutions of mer- 
 curic chloride and potassium iodide to be poured 
 simultaneously into water in making mercuric iodide? 
 Because if either solution is poured into the other a 
 soluble double compound is formed. 
 
 Why does the formula call for a slight excess of 
 potassium iodide in making mercuric iodide? Be- 
 cause it is desirable to have all the mercuric chloride 
 decomposed, even though there is a little loss in sub- 
 sequent washings. 
 
 Why is the solution of mercuric chloride poured 
 into the solution of sodium hydroxide and not the 
 
CHEMICALS. 105 
 
 hydroxide into the mercury? Having the alkaU in 
 excess, the yellow mercuric oxide is precipitated, 
 while if the mercury is in excess the red-brown oxy- 
 chloride of mercury is precipitated. 
 
 Why are the solutions of mercuric chloride and 
 sodium hydroxide well diluted before mixing, in 
 making yellow oxide of mercury? To avoid the red- 
 brown oxy chloride. For the same reason the mercury 
 solution must be added slowly with constant stir- 
 ring to the alkali solution. 
 
 Why is the mixture of these solutions allowed to 
 stand for an hour? To complete the reaction and 
 decompose any oxychloride formed. 
 
 Why must the sodium hydroxide be free from car- 
 bonate? The carbonate forms a basic compound 
 which is more red. 
 
 Why does the U. S. P. direct a temperature of 
 about 30° C? The higher the temperature the quicker 
 will be the reaction, but a temperature above 30° C. 
 tends to the formation of a reddish salt. 
 
 Why should mercuric oxide be washed until the 
 washings give no turbidity with a solution of mer- 
 curic chloride? So long as a turbidity results there 
 is some sodium hydroxide present. 
 
 Why should yellow oxide of mercury be protected 
 from the light? Light decomposes it, forming metal- 
 lic mercury and oxygen and the metallic mercury 
 causes it to darken. It changes more readily than 
 the red on account of its greater fineness. 
 
 Why was the yellow subsulphate of mercury called 
 
106 WHYS IN PHARMACY. 
 
 turpeth mineral? It is a mineral substance some- 
 what resembling powdered turpethium in appearance. 
 
 Why is nitric acid used in making yellow subsul- 
 phate of mercury (1890)? Because it assists the 
 formation of mercuric sulphate. 
 
 Why is mercuric sulphate solution evaporated to 
 dryness and heated on a sand-bath? To get rid of 
 the excess of acid. 
 
 Why is mercuric sulphate added to boiling water 
 in making yellow subsulphate of mercury? Because 
 this causes decomposition and the formation of the 
 basic compound. 
 
 Why is an excess of ammonia used in making am- 
 moniated mercury, and why is the precipitate washed 
 with water containing ammonia? Because there is 
 liability of forming a yellow basic salt unless am- 
 monia is present. 
 
 Why is the solution of mercuric chloride filtered 
 before pouring into ammonia in making ammoniated 
 mercury? To remove any calomel which, if present, 
 would give a black compound with ammonia. 
 
 Why should ammoniated mercury not be washed 
 with an excessive amount of water or dried with 
 heat or exposed to light? All tend to change it to 
 a yellow basic compound. 
 
 Why is chalk made into a mass with water before 
 mixing with the finely divided mercury in making 
 mercury with chalk? If an attempt were made to 
 mix the dry carbonate with the mixture of honey 
 and divided mercury it would become so drv that 
 
. CHEMICALS. 107 
 
 the mixing would cause the union of the small glob- 
 ules of mercury. 
 
 Why should mercury with chalk be powdered with- 
 out trituration? Rubbing causes the small particles 
 of mercury to unite to form larger globules. 
 
 Why should mercury with chalk be protected from 
 the air and light? Metallic mercury when finely 
 divided is easily oxidized and becomes darker. 
 
 Why is sodium carbonate preferred to potassium 
 carbonate in making magnesium carbonate? It is 
 cheaper and purer; and the sodium sulphate is 
 easier to wash out than the potassium sulphate. 
 
 Why does magnesium carbonate vary in com- 
 position? The extra heat used in making the 
 heavy carbonate drives off more of the carbon di- 
 oxide. 
 
 Why does magnesium carbonate vary in density? 
 The heavy salt is made by mixing hot concentrated 
 solutions of magnesium sulphate and sodium car- 
 bonate, and the light salt by mixing cold dilute solu- 
 tions. 
 
 Why does heat aid in the precipitation of mag- 
 nesium carbonate from a mixture of the solutions of 
 magnesium sulphate and sodium carbonate? Heat 
 drives off the carbon dioxide, which otherwise re- 
 mains and holds some of the magnesium in solution 
 as the bicarbonate. 
 
 Why should the heating of magnesium carbonate 
 not be continued too long, nor allowed to get above 
 a dull red heat, in making magnesia? Both con- 
 
108 WHYS IN PHARMACY. 
 
 clitions tend to make magnesia lumpy and granular 
 and less readily soluble in acids. 
 
 Why are some magnesium oxides much lighter 
 than others? Heavy magnesia is made by calcining 
 heavy magnesium carbonate, while the light is made 
 by calcining the light magnesium carbonate. High 
 heat, pressure of the carbonate before calcining, 
 moistening the carbonate before calcining, heavy 
 trituration of magnesia, all have a tendency to render 
 the magnesia more dense. 
 
 Why, in mixing magnesia with water, should the 
 magnesia be added to a large excess of water? A 
 small amount of water makes the magnesia hard, 
 gritty, and lumpy, while a large amount of water 
 gives a smooth gelatinous hydroxide. 
 
 Why does one part of magnesia with fifteen parts 
 of water give a solid mass? Water is taken up to 
 form the hydroxide. 
 
 Why is it generally necessary to add a little acetic 
 acid to get a clear solution of lead acetate in water? 
 On exposure to air lead acetate absorbs carbon di- 
 oxide and forms the insoluble lead carbonate and 
 the acid dissolves this. 
 
 Why should the solution of lead acetate be added 
 to potassium iodide in making lead iodide? If the 
 iodide is added to the lead an oxy iodide is formed. 
 
 Why is it necessary to have free nitric acid present 
 in crystallizing lead nitrate? If it is not present 
 the crystals will be more or less opaque. 
 
 Why does lead oxide vary in color? The color 
 
CHEMICALS. 109 
 
 depends on the temperature of oxidation and the rapid- 
 ity of coohng, being more yellow when cooled rapidly. 
 
 Why is a warm mortar directed in making potassa 
 with lime? Potassa is hygroscopic, and heat prevents 
 the absorption of moisture while mixing. 
 
 Why should a higher heat than just enough to 
 cause a chemical reaction be avoided in making sul- 
 phurated potassa? High heat tends to the forma- 
 tion of potassium sulphate. 
 
 Why must sulphurated potash be protected from 
 air? To prevent the absorption of moisture and 
 oxygen which will change it to a sulphate. 
 
 Why is acetic acid used in excess in making potas- 
 sium acetate? If the alkali is in excess the salt is 
 apt to be colored. 
 
 Why is potassium acetate heated in estimating it? 
 Heat converts it into the carbonate, which can be 
 estimated by a standard acid solution. 
 
 Why is methyl orange preferable to phenolphtha- 
 lein and most other indicators in titrating a carbon- 
 ate? It is not affected by carbon dioxide. 
 
 Why is potassium bicarbonate purer than the 
 normal carbonate? The carbonate is quite strongly 
 alkaline and dissolves silica. In passing carbon di- 
 oxide into a solution of carbonate, it changes the 
 normal carbonate to the bicarbonate, precipitates 
 the silica, and the bicarbonate can then be crystallized. 
 
 Why is charcoal used in making potassium bro- 
 mide when it is made by the direct combination of 
 bromine and potassium hydroxide? While most of 
 
110 WHYS IN PHARMACY. 
 
 the bromine combines with the potassium to form 
 potassium bromide, about a sixth of it forms potas- 
 sium bromate; and heating the bromate with char- 
 coal reduces it to the bromide. 
 
 Why does the addition of dilute sulphuric acid 
 to potassium bromide, resulting in the getting of 
 bromine, indicate the presence of a bromate, since 
 dilute sulphuric acid does not liberate bromine from 
 either a bromide or a bromate? Sulphuric acid liber- 
 ates hydrobromic acid and bromic acid, and these 
 react on each other, liberating bromine from both. 
 
 Why does the U. S. P. allow potassium bromide to 
 be slightly alkaline? The presence of a small amount 
 of carbonate prevents the liberation of bromine. 
 
 Why, in estimating a chloride as an impurity in 
 potassium bromide, does the U. S. P. direct that it 
 should not require more than 25.85 cc. of N/10 
 silver-nitrate solution to produce a red color? A 
 red color is produced only after all of the bromide and 
 chloride are precipitated. Potassium chloride takes 
 more silver nitrate for precipitation than the same 
 weight of potassium bromide, consequently the Phar- 
 macopoeia limits the amount of silver. 
 
 Why does potassium carbonate occur in granular 
 form? It is deliquescent and not easily crystallized 
 and in the granular form it is more permanent. 
 
 Why is potassium chlorate heated with aluminum 
 and potassium hydroxide in testing it for a nitrate 
 as an impurity? The chlorate and nitrate are re- 
 duced. Ammonia is formed from the nitrate. 
 
CHEMICALS. Ill 
 
 Why does the getting of a precipitate by adding 
 acetic acid to potassium citrate indicate the presence 
 of a tartrate? If the tartrate is present it is there 
 in the form of a normal salt and is soluble. Acetic 
 acid converts it into the bitartrate, which is spar- 
 ingly soluble. 
 
 Why, in estimating potassium cyanide, does the 
 amount of silver nitrate solution taken to produce 
 a permanent precipitate represent only one half of 
 the silver solution necessary to make pure silver cya- 
 nide? One molecule of potassium cyanide combines 
 with one of silver cyanide to form the insoluble silver 
 cyanide. This then combines with another molecule 
 of potassium cyanide to form a soluble double com- 
 pound. It is only after all of the potassium cyanide 
 is taken up in this double compound that the addi- 
 tion of silver nitrate causes a permanent precipitate. 
 
 Why is potassium and sodium tartrate called 
 Rochelle salt? It was first prepared at Rochelle, 
 France. 
 
 Why does the addition of acetic acid to a strong 
 solution of Rochelle salt produce a precipitate? The 
 acid combines with the sodium and liberates the 
 potassium acid tartrate which is not very soluble. 
 
 Why is potassium bicarbonate used rather than 
 the normal carbonate in making potassium hydrox- 
 ide? It is purer. 
 
 AVhy is the solution of potassium hydroxide evapo- 
 rated in metallic vessels? Because glass or earthen- 
 ware is attacked by alkalies, forming soluble silicates. 
 
112 WHYS IN PHARMACY. 
 
 Why are green glass bottles better than flint 
 bottles for containing potassium hydroxide? The 
 green glass is not so readily attacked as the flint. 
 
 Why should a solution of potassium hypophos- 
 phite be evaporated at a temperature below its 
 boiling-point? At the boiling-point of the solution 
 there is danger of decomposition and also danger 
 of explosion. 
 
 Why is a solution of ammonium molybdate of 
 no service in testing potassium hypophosphite for 
 a phosphate as an impurity? The ammonium 
 molybdate solution contains free nitric acid which 
 would oxidize the hypophosphite to a phosphate, 
 and thus a test would be obtained though a phos- 
 phate may not have been there originally. 
 
 Why in testing potassium hypophosphite for a 
 chloride is the hypophosphite first heated with 
 nitric acid? To oxidize the hypophosphite to a 
 phosphate so that it will not reduce the silver nitrate 
 and interfere with the test. 
 
 Why is it best to evaporate a solution of potassium 
 iodide at about 50° C. to 60° C. in crystallizing the 
 salt? Larger crystals are formed than if a higher 
 temperature were used and the solution does not 
 creep over the edges of the dish so much as it does 
 at a lower temperature. 
 
 Why is potassium iodide sometimes whiter and 
 more opaque than it is at others? Potassium car- 
 bonate tends to make it whiter. 
 
 Why is potassium carbonate often an impurity 
 
CHEMICALS. 113 
 
 in potassium iodide? It tends to prevent the libera- 
 tion of iodine. 
 
 Why is the httle amount of potassium carbonate 
 that is left in objectionable? It makes the iodide 
 more hygroscopic and also alkaline, so that a solu- 
 tion of it may cause precipitation with metallic 
 and alkaloidal salts when a pure iodide would 
 not. 
 
 Why does dilute sulphuric acid liberate iodine 
 from potassium iodide if it is contaminated with 
 iodate? Sulphuric acid liberates hydriodic and 
 iodic acids, and these react on each other, liberating 
 iodine. 
 
 Why in testing potassium iodide for a nitrate is 
 the nitrate changed to ammonia instead of making 
 the test with ferrous sulphate and sulphuric-acid? 
 Concentrated sulphuric acid liberates iodine which 
 would interfere with the test. 
 
 Why does the U. S. P. direct that not more than 
 30.8 cc. of decinormal silver-nitrate solution be used 
 for 0.5 gram of potassium iodide, in testing this salt? 
 More would indicate contamination with a bromide 
 or chloride. 
 
 Why is asbestos used in filtering a solution of 
 potassium permanganate? Asbestos is not acted on 
 like filter-paper, cotton, or an organic medium. 
 
 Why is sodium carbonate allowed to effloresce 
 before heating, in making dried sodium carbonate? 
 Because, if heated at first, the salt dissolves in the 
 water of crystallization; the water is driven off 
 
114 WHYS IN PHARMACY. 
 
 with difficulty, and the product thus obtained is 
 granular instead of being smooth. 
 
 Why is commercial sodium chloride hygroscopic? 
 It often contains a little magnesium chloride or cal- 
 cium chloride, either of which is deliquescent. 
 
 Why does sodium hydroxide produce heat when 
 dissolved in water? A large number of hydroxides 
 are formed and the chemical reactions cause the 
 heat. 
 
 Why does sodium hydroxide sometimes appear 
 efflorescent? Caustic soda is deliquescent and also 
 absorbs carbon dioxide from the air. When it has 
 absorbed considerable carbon dioxide the carbonate 
 formed becomes efflorescent. 
 
 Why does sodium iodide produce heat when dis- 
 solved in water, while the corresponding potassium 
 iodide does not? Official sodium iodide is anhydrous 
 and takes up two molecules of water of crystallization. 
 
 Why is the common method of detecting a nitrate 
 by means of ferrous sulphate and sulphuric acid not 
 used in testing sodium iodide for a nitrate? Strong 
 sulphuric acid liberates iodine from an iodide and 
 this would interfere with the' test. 
 
 Why is heat used in making sodium sulphocar- 
 bolate? Heat forms a para-salt, which is official. 
 In the cold the ortho-salt is formed. 
 
 Why is sodium salicylate usually slightly acid? 
 A little free acid is left in it because it does not 
 turn red as quickly when the salt is a little acid as 
 when it is neutral or alkaline. 
 
CHEMICALS. 11 
 
 K 
 
 Why is cotton or glass-wool better than filter- 
 paper for filtering a solution of a salicylate? Filter- 
 paper often contains a little iron which gives a pink 
 or red color with a salicylate. 
 
 Why is the receiving-chamber not allowed to get 
 hotter than about 110° C. in making sublimed sul- 
 phur? At about 115° C. sulphur melts and would 
 then run together and form brimstone. 
 
 Why should sulphur be protected from moisture? 
 Moisture aids oxidation. 
 
 Why is ammonia used in making washed sulphur? 
 It neutralizes any free acid, making it easier to wash 
 out, and it dissolves the sulphide of arsenic which is 
 frequently present. 
 
 Why is hydrochloric acid used short of neutraliza- 
 tion in making precipitated sulphur? Because if 
 an excess of acid is used, or even enough to cause 
 neutrality, the soluble compound of lime and sulphide 
 of arsenic is decomposed, and sulphide of arsenic is 
 precipitated with sulphur. 
 
 Why should sulphuric acid not be substituted for 
 hydrochloric acid in making precipitated sulphur? 
 Sulphuric acid forms the nearly insoluble calcium 
 sulphate, which could not be removed. 
 
 Why is precipitated sulphur whiter than the flowers 
 of sulphur? Because it is more finely divided. 
 
 Why is hydrochloric acid used in purifying talcum? 
 It forms soluble compounds with many of the impuri- 
 ties, leaving the magnesium silicate. 
 
 Why does zinc chloride frequently not give a 
 
116 WHYS IN PHARMACY. 
 
 clear solution with water? On account of a basic 
 chloride which can best be gotten rid of by filtering 
 through asbestos or glass-wool. 
 
 Why is it necessary to treat zinc sulphate with 
 alcohol in order to determine the presence or absence 
 of free acid? The salt itself is acid, but it is not 
 soluble in alcohol, while the free acid is. 
 
ORGANIC DRUGS. 
 
 Why is a powdered drug more liable to deteriora- 
 tion than the whole drug? Because more surface is 
 exposed to light and air. 
 
 Why should ether be kept away from light and 
 air? It is slowly oxidized, forming hydrogen dioxide, 
 ozone, aldehyde, and acetic and formic acids. 
 
 Why is heat produced when alcohol and water 
 are mixed? Chemical reaction and contraction of 
 volume take place, forming hydrates of alcohol. 
 
 Why is alcohol used in purifying aloes? The 
 melted aloes is too thick to pass through the sieve; 
 alcohol thins it. 
 
 Why is the sieve dipped in hot water just before 
 pouring the melted aloes through? This prevents 
 the clogging of the sieve by the chilled mass. 
 
 Why should aspidium be made up into prepara- 
 tions soon after collecting? The crude drug loses 
 strength more rapidly than its preparations do. 
 Filicic acid is said to change to an inactive anhy- 
 dride. 
 
 Why should the medicinal parts of belladonna be 
 
 collected from the second to fourth years? The 
 
 117 
 
118 WHYS IN THARMACY. 
 
 proportion of atropine is greater during that period. 
 In the young plants hyoscyamine predominates. 
 
 Why should the large woody roots of belladonna 
 be rejected? The alkaloids are mostly in the bark. 
 
 Why was the name belladonna applied to tliis 
 drug? The word signifies beautiful lady. It is said 
 that Italian ladies used this drug to dilate the pupils 
 of the eyes, thus giving a brilliant appearance. 
 
 Why does the U. S. P. give the title ''caffeina 
 citrata'' instead of caffeinae citras? This prepara- 
 tion is probably a mixture of caffeine and citric 
 acid and not a true salt as would be indicated by 
 the term caffeinse citras. 
 
 Why does camphor subhme on the back of the 
 stock-bottle? The back of the bottle is nearer the 
 wall which is generally cooler than the air in the 
 store. 
 
 Why do some persons claim that cannabis indica 
 should be kept in perforated boxes? They say that 
 stored in this way it retains its aromatic properties 
 for two or three years, whereas when kept in tight 
 containers the water retained by the drug induces 
 fermentation. 
 
 Why is acid used in purifying animal charcoal? 
 It dissolves out the phosphates and carbonates. In 
 decolorizing acid liquids only the purified charcoal 
 should be used. 
 
 Why is animal charcoal used for decolorizing 
 fluids rather than wood charcoal? It hao a stronger 
 property of absorbing colors. 
 
ORGANIC DRUGS. 119 
 
 Why is animal charcoal not effective as a decolor- 
 izing agent after it has been exposed to the air for 
 some time? It has absorbed gases from the air 
 which prevent the absorption of coloring-matter. 
 Heating the charcoal will again make it effective. 
 
 Why is starch sometimes found in beeswax when 
 it is not put there as an adulterant? In pressing 
 wax into cakes, starch is put on to the rollers to 
 prevent the wax from sticking. 
 
 Why does spermaceti become rancid on exposure 
 to air? Rancidity is due to a change in the oil 
 which has not been entirelv removed. 
 
 Why does the U. S. P. allow as much as one per 
 cent, of alcohol to be present in chloroform? This 
 small amount of alcohol acts as a preservative; 
 chloroform is quite easily decomposed when pure. 
 
 Why is chondrus exposed to the sun for a week 
 or more? To bleach it. 
 
 Why was the drug cinchona given that name? 
 From the fact that the wife of the fourth Count 
 of Chincon was cured of malaria by it, and she 
 introduced it into Europe. 
 
 Why are some specimeixS of coccus cacti black 
 and some silver-gray? The silver-gray bugs are 
 killed by the heat of a fire, while the black ones 
 are killed by hot water. 
 
 Why are the cochineal insects called coccus cacti? 
 They get the name coccus from their resemblance to 
 a berry and the name cacti from the fact that they 
 feed on a species of cactus. 
 
120 WHYS IN PHARMACY. 
 
 Why should the pericarp of cardamom be dis- 
 carded? It contains but Httle oil. 
 
 Why is creosote usually obtained from beechwood? 
 Beechwood yields a rather larger amount than other 
 woods. 
 
 Why is the word ''beechwood" so often used to 
 describe creosote? An impure carbolic acid is some- 
 times sold under the name creosote. 
 
 Why are cubebs gathered while still green? They 
 are more pungent then and do not fall off so 
 readily. 
 
 Why should ergot not be kept longer than a year? 
 It deteriorates rapidly. It is said that this is due 
 to the fixed oil becoming rancid, and that if the oil 
 is removed the medicinal properties remain unchanged 
 for a long time. 
 
 Why are the fluid extract and the extract of 
 ergot the best preparations? They contain all the 
 constituents of the drug, and no one constituent 
 represents the drug. 
 
 Why is eucalpytus cultivated in malarial dis- 
 tricts? The tree absorbs much water, drying up 
 the ground, and its eminations are antagonistic to 
 the malarial germ. 
 
 Why is gentian used more than other bitters? It 
 has a pleasanter taste and does not contain tannin, 
 so can be given with iron. 
 
 Why is alcohol used in making purified ox-gall? 
 Alcohol precipitates ine t matter that would make 
 the gall tough when dried if left in. 
 
ORGANIC DRUGS. 121 
 
 Why is ginseng valued so highly by the Chinese? 
 The roots often grow into a form resembling that 
 of a man, and the Chinese have a superstition that 
 this drug will cure nearly all diseases. 
 
 Why is glycerin in itself not a good solvent? It 
 is so viscid that it prevents diffusion. 
 
 Why is glycerin used in purified honey? To aid 
 preservation. 
 
 Why is glycerin used in making gelatin capsules? 
 It prevents the capsules from cracking so readily. 
 
 Why is the Spanish glycyrrhiza preferred to the 
 Russian? It is a little sweeter. 
 
 Why is sulphuric acid used in making ammoniated 
 glycyrrhizin? It is used to precipitate glycyrrhizic 
 acid, which can be filtered out, washed, and purified. 
 Ammonia water added later converts it into the 
 soluble salt. 
 
 Why is purified cotton more absorbent than 
 ordinary cotton? Ordinary cotton has oil and 
 fatty matter in it which prevent the absorption of 
 water. In purified cotton these substances have 
 been removed. 
 
 Why are liquid preparations of kino unstable? 
 The pectin present often causes gelatinization. 
 
 Why is lycopodium called vegetable sulphur? It 
 is yellow like sulphur and burns readily. 
 
 Why are nutmegs limed? To protect them from 
 insects. 
 
 Why is sodium hydroxide used in obtaining pure 
 carbolic acid from the crude product? Crystalline 
 
122 WHYS IN THARMACY. 
 
 sodium phenolate is formed, leaving fluid hydro- 
 carbons and other impurities. The sodium com- 
 pound can be heated to 170° C. without decom- 
 position, thus getting rid of other substances. 
 
 Why was phenol called an acid? Because it 
 combines with some bases, though not readily 
 neutralizing alkalies. 
 
 Why was the portion of the distillate coming 
 over between 165° C. and 190° C. called '^dead oil''? 
 Because it was thought to be valueless. 
 
 Wh}^ should the melting-point of carbolic acid be 
 not less than 40° C. and its boihng-point not over 
 188° C? A lower boiling-point or a higher melting- 
 point indicates a less h3^drated phenol. 
 
 Why should care be used in melting carbolic 
 acid ? It forms an inflammable vapor, and when this 
 is mixed with air it may be exploded with violence 
 by contact with a flame. 
 
 Why does carbolic acid acquire a red color? 
 Some writers say it is due to the presence of aurin 
 and rosolic acid, which form red compounds by 
 absorption of carbon dioxide and oxygen. Other 
 writers say it is due to absorption of ammonia 
 and ammonium nitrate, or to the alkalies in the 
 glass of the container, or to the presence of 
 iron. 
 
 Why does the U. S. P. give the solubihty of car- 
 bolic acid as 19.6 parts of water when the acid makes 
 a liquid with less than ten per cent, of water? The 
 addition of a small amount of water converts phenol 
 
ORGANIC DRUGS. 123 
 
 into hydrates, which are Hquid but not very soluble 
 in water. 
 
 Why is an excess of bromine used in estimating 
 carbolic acid? So as to precipitate all of the acid 
 as tribromophenol. 
 
 Why is potassium iodide used in estimating car- 
 boHc acid? The excess of bromine combines with 
 the potassium, liberating an equivalent amount 
 of iodine, which is more easily and accurately 
 estimated by sodium thiosulphate than the bro- 
 mine. 
 
 Why are the preparations of pilocarpus leaves less 
 reliable than preparations of pilocarpine? The 
 leaves contain jaborine which is antagonistic to 
 pilocarpine in action. The proportion of the two 
 alkaloids varies in different samples of leaves. 
 
 Why is physostigma called ordeal bean? In 
 Africa some of the native tribes use it to determine 
 the guilt or innocence of a person suspected of a 
 crime. The accused is made to eat the beans 
 until he vomits or dies. If he vomits and lives he 
 is innocent, but if he dies he is guilty. 
 
 Why is podophyllum called vegetable mercury? 
 Because it resembles calomel in its action. 
 
 Why must the mixture of acids be cooled before 
 putting in the cotton, in making pyroxyhn? Because 
 heat causes the formation of higher nitrates of 
 cellulose which are less soluble in alcohol and ether 
 and more explosive. 
 
 Why should the bark of rhamnus purshiana be 
 
124 WHYS IN PHARMACY. 
 
 one or more years old before using? When fresh it 
 contains a principle that causes griping, but after 
 standing for a time this principle disappears and 
 the bark no longer gripes. 
 
 Why should red rose flowers be gathered before 
 complete maturity and dried rapidly? Collecting 
 early makes them more astringent, and drying 
 rapidly preserves the color and odor. 
 
 Why should santonin and preparations containing 
 it be put into containers which protect it from the 
 light? Light causes santonin to become yellow. 
 
 Why is santonin better than the sodium santo- 
 ninate which was formerly official? Because it is not 
 so soluble, so irritating, or so readily absorbed. 
 
 Why should mustard not be heated over 60° C. 
 in making mustard poultice? A heat of 65° C. 
 makes the ferment, myrosin, inert so that it does 
 not convert the glucoside, sinigrin, into the volatile 
 oil. 
 
 Why should powdered mustard not give a blue 
 color with iodine? A blue color would indicate 
 the presence of starch as an adulterant; mustard 
 does not contain starch when pure. 
 
 Why should only black mustard be used in phar- 
 macy? It yields the volatile oil of mustard while 
 the white mustard does not. 
 
 Why do ribbons of tragacanth have longitudinal 
 ridges on them? Tragacanth exudes at night 
 through incisions made in the bark. The exudation 
 ceases during the day and the juice dries, and th.3 
 
ORGANIC DRUGS. 125 
 
 ridge indicates the amount secreted in the twenty- 
 four hours. 
 
 Why is ginger washed in boihng water? To 
 prevent it from germinating. 
 
 Why is ginger coated with hme? To protect it 
 from insects. 
 
ALKALOIDS. DRUG ASSAYS. 
 
 Why was the term '^alkaloid" apphed to tho 
 basic principles found in plants? Alkaloid means 
 alkali-like — i.e., these principles, like alkahes, com- 
 bine with acids to form salts. 
 
 Why is the definition, '^An alkaloid is an organic 
 base found in the plant kingdom, and which is a 
 pyridin derivative," not generally acceptable? 
 Because this shuts out at least two principles now 
 classed as alkaloids, viz., caffeine and theobromine. 
 
 Why does the prefix ^^ hydro" generally enter 
 into the name of an alkaloidal salt? In forming a 
 salt of an alkaloid, the hydrogen of the acid is not 
 displaced; the whole acid is added on, and the 
 prefix shows this. 
 
 Why should alkaloids be protected from the hght? 
 Light often decomposes alkaloids, slowly causing 
 a darkening. 
 
 Why is less dependence now placed on chemical 
 tests for alkaloids than formerly? We now know 
 that many synthetic bases and ptomaines give 
 reactions similar to, if not identical with, those 
 given by alkaloids. 
 
 126 
 
ALKALOIDS. 127 
 
 Why is the complete separation and estimation 
 of alkaloids so difficult? Alkaloids frequently do 
 not form compounds with any known reagent that 
 are sufficiently insoluble to permit of separation. 
 
 Why is the general method of estimating alkaloids 
 by weighing the free alkaloid objectionable? If the 
 alkaloid is first precipitated, the mother liquid will 
 hold more or less of it in solution, and the alkaloid 
 will rarely come down pure. If the alkaloid is 
 removed by dissolving it in some immiscible solvent, 
 it will be mixed with some foreign matter. 
 
 Why is the general method of estimating alkaloids 
 by precipitation with Mayer's reagent, and then 
 weighing the precipitate, objectionable? The com- 
 pound formed between the alkaloid and the reagent 
 may vary under different conditions of precipitation. 
 Drying this compound may change its composi- 
 tion. Mayer's reagent precipitates many other sub- 
 stances. 
 
 Why is the method of estimating alkaloids by a 
 standard solution of Mayer's reagent objectionable? 
 It is very difficult to tell when the end reaction is 
 obtained, and the amount required varies with the 
 concentration of the alkaloidal solution, as well as 
 with other conditions. 
 
 Why is the method of estimating alkaloids by 
 standard acid and alkali solutions objectionable? 
 Many times- it is difficult to detect the end reaction, 
 and various indicators act differently with alkaloids. 
 By precipitating the alkaloid from an acid solution 
 
128 WHYS IN THARMACY. 
 
 by iodine, filtering, and titrating the filtrate the 
 end reaction is more distinct. 
 
 Why, in extracting alkaloids for assaying, are 
 acidulated water and alkaline immiscible solvents 
 alternately used? The separation of alkaloids by 
 this method depends upon the facts that free alka- 
 loids are generally soluble in immiscible solvents and 
 insoluble in water, and the alkaloidal salts are soluble 
 in water and insoluble in the immiscible solvents. 
 
 Why should such alkaloids as atropine, aconitine, 
 hyoscyamine, and cocaine not be left in an alkaline 
 solution any longer than is necessary in separating 
 them from the crude drugs? They are all easily 
 decomposed by simple contact with an alkali for a 
 short time. 
 
 Why should cinchona be in very fine powder for 
 assay purposes? The bark is hard to exhaust. 
 
 Why is a mixture of ether, chloroform, and am- 
 monia used to extract the alkaloids in assaying the 
 bark? Ammonia liberates the alkaloids, which are 
 then dissolved in chloroform and ether. 
 
 Why should care be taken to measure accurately 
 and to allow no evaporation of this liquid? 150 cc. 
 are used to extract the drug, and 100 cc. of this are 
 taken to represent two thirds of the drug taken. If 
 evaporation is allowed, 100 cc. will represent more 
 than 10 grams. 
 
 AVhy are the 100 cc. treated with dilute sulphuric 
 acid? Acid converts the alkaloids into sulphates 
 which are soluble. 
 
ALKALOIDS. 129 
 
 Why is the acid fluid shaken with ammonia, 
 ether, and chloroform in estimating anhydrous 
 alkaloids? Ammonia liberates the alkaloids; and 
 the ether and chloroform dissolve them. 
 
 Why ''add 3 cc. of ether to the dry residue and 
 evaporate again''? To aid the complete removal of 
 moisture. 
 
 Why is quinine (free alkaloid) mixed with am- 
 monium sulphate and water, and then dried, in the 
 official method of testing quinine for other cinchona 
 alkaloids? In order to convert all the alkaloids 
 into sulphates, ammonia being volatilized. 
 
 Why are the alkaloids converted into sulphates? 
 Because quinine sulphate is more insoluble in water 
 than the other sulphates, and treating this mixture 
 with water dissolves most of the sulphates of alka- 
 loids other than quinine and comparatively little of 
 the quinine sulphate. 
 
 Why is the mixture of cinchona alkaliods digested 
 with water at 65° C. then kept at a temperature 
 of 15° C. for two hours and filtered at that tem- 
 perature? When quinine sulphate is crystalHzed 
 from a liquid containing other alkaloids the crystals 
 seem to take in some of the other alkaloids (they 
 are inside the crystals, not merely on the outside). 
 The elevated temperature is for the purpose of 
 dissolving more of the quinine. The mixture is 
 cooled to 15° C. and filtered at that temperature 
 in order to get uniform results and prevent too 
 much quinine sulphate from going into solution; 
 
130 WHYS IN PHARMACY. 
 
 excess of quinine is not dissolved by ammonia. 
 The mixture is kept at 15° C. for two hours before 
 filtering so as to allow complete crystallization, 
 getting only a saturated filtrate. 
 
 Why is ammonia added to the filtrate? By add- 
 ing the stated amount of ammonia to the given 
 amount of filtrate, enough ammonia is added to 
 Hberate all of the alkaloids and to redissolve the 
 quinine which is present, but not the other alkaloids. 
 The test is based on two principles: (1) the com- 
 parative solubility of the sulphates of alkaloids 
 other than quinine in water, and (2) the comparative 
 insolubihty of these alkaloids in ammonia when in 
 the free state. 
 
 Why are the other salts of quinine converted into 
 the sulphate in applying this test? To get uniform 
 results and to fulfil the condition as laid down in 
 the first principle. 
 
 Why is quinine tannate nearly tasteless? Because 
 it is so nearly insoluble. 
 
 ^YhJ is nitric acid used in estimating strychnine 
 in nux vomica and its preparations? Nitric acid 
 decomposes brucine which is extracted with the 
 strychnine and changes it so that chloroform no 
 longer dissolves it from an alkaline solution. 
 
 Why is the filter wetted with chloroform just 
 before filtering the chloroform extract of the mix- 
 ture after treating with nitric acid? So that the 
 filter will not retain any strychnine and to prevent 
 any aqueous solution from getting into the flask. 
 
ALKALOIDS. 131 
 
 Why is it particularly objectionable to have any 
 of the aqueous liquid get into the flask at this stage 
 of the process? The aqueous liquid contains free 
 alkali which would neutralize some of the standard 
 acid, acting like strychnine. 
 
 Why is fiftieth-normal potassium hydroxide used 
 to titrate back the excess of decinormal acid? 
 Rather more accurate results can be obtained than 
 when decinormal alkali is used. 
 
 Why divide the number of cubic centimeters of 
 fiftieth-normal potassium hydroxide by 5? So as to 
 reduce the fiftieth-normal to its equivalent in deci- 
 normal. 
 
 Why subtract this quotient from 10? 10 cc. of 
 decinormal acid were used at first. Subtracting the 
 above quotient from 10, the remainder is the number 
 of cubic centimeters of acid which were taken up or 
 neutralized by the alkaloids. 
 
 Why multiply the remainder by 0.0332? Each 
 cubic centimeter of decinormal acid neutralizes 
 0.0332 gram of strychnine. 
 
 Why is this product multiplied by 50? The assay 
 method gets the alkaloid in 2 grams of extract, and 
 by multiplying by 50 gives the weight in 100 grams. 
 
 Why is it difficult to tell when the acid is exactly 
 neutralized by the alkali? The hquid which is to 
 be titrated is often colored. It is better to add 
 neutral Mayer's reagent, or a solution of iodine, 
 to the acid solution, filter, and then titrate the filtrate 
 with the alkali. 
 
132 WHYS IN PHARMACY. 
 
 Why is manganese dioxide preferred by some 
 workers to j3otassium dichromate, in testing for 
 strychnine? Potassium dichromate itself gives a 
 color that may hide the strychnine color if strych- 
 nine is present in only small amounts. 
 
 Why is powdered opium better for making prepa- 
 rations than the gum? It is more uniform and 
 does not change so much on keeping. 
 
 Why is it that water will exhaust opium when it 
 will exhaust almost no other alkaloidal drug? The 
 alkaloids of opium exist in the form of meconates 
 and sulphates, which are soluble, while in most 
 other drugs the alkaloids are in combination with 
 tannic acid, which salts are nearly insoluble. 
 
 Why, in assaying gum opium, should a cone- 
 shaped piece be taken with the apex of the cone 
 at the center of the lump? The outside of the 
 lump is always dryer than the center, and by taking 
 a cone a proportional amount of the dry and the 
 moist opium is obtained. 
 
 Why, in the official method of estimating opium, 
 is an Erlenmeyer flask directed to be used? The 
 crystals can be removed more easily. The writer 
 prefers a Florence or globe-shaped flask, because there 
 is less area of surface when decanting the ether, and 
 consequently the ether can be more closely separated. 
 
 Why are alcohol, ether, and ammonia added to 
 the concentrated extract of opium in assaying it? 
 The alcohol prevents the precipitation of a con- 
 siderable amount of foreign matter by ammonia. 
 
ALKALOIDS. 133 
 
 Ether keeps in solution the alkaloids other than 
 morphine, they being soluble in ether while mor- 
 phine is not. Ammonia liberates the alkaloids from 
 their salts and morphine is precipitated. The aqueous 
 extract is concentrated so that as little morphine will 
 be left in the mother-liquor as possible. 
 
 Why does the U. S. P. direct to shake this mix- 
 ture for ten minutes? Agitation aids precipitation, 
 making the morphine come down more promptly 
 and completely. Even then the mixture must stand 
 six hours or more. 
 
 Wiry should the mixture not stand longer than 
 about twenty-four hours? After that time other 
 matter than morphine precipitates. 
 
 Why does the U. S. P. direct two rapidly acting 
 filters? Two filter-papers are used to quicken fil- 
 tration. The writer much prefers a single filter of 
 hardened paper from which the crystals can be 
 readily removed without leaving any on the paper, 
 or getting fibers of paper mixed with the crystals. 
 
 Why are the contents of the flask washed twice 
 with ether? So as to remove other alkaloids as 
 far as possible. 
 
 Why are the crystals washed with alcohol satu- 
 rated with morphine? They are washed with alco- 
 hol to remove coloring and other foreign matter. 
 The alcohol is saturated with morphine so that 
 it will not dissolve any of the crystals. 
 
 Why is the alcohol saturated with morphine 
 washed out with ether? If the alcohol were not 
 
134 WHYS IN PHARMACY. 
 
 washed out it would evaporate, leaving the mor- 
 phine originally dissolved in it, making the results 
 too high. 
 
 Why are the crystals dried at a temperature not 
 exceeding 60° C? If the crystals were dried at 
 100° C. part but not all of the water of crystalhza- 
 tion would be driven off, the amount varying. A 
 higher temperature is necessary to drive off all 
 the water, and there is some danger of the decom- 
 position of morpliine. Morphine crystallizes and is 
 weighed with one molecule of water. 
 
 Why are the crystals transferred to a watch-glass 
 for weighing? They cannot be weighed accurately 
 on filter-paper, since filter-paper absorbs moisture 
 during weighing. Then, too, filter-paper loses some 
 weight on being subjected to various solvents. 
 
 Why is lime water used in assaying opium? It 
 is used to dissolve morphine, leaving some impurities 
 undissolved, which are filtered out. 
 
 Why is the use of lime water objectionable? 
 The filter-papers, though counterpoised at first, do 
 not necessarily retain the same amount of calcium 
 hydroxide; then more qr less of the hydroxide is 
 converted into the carbonate. This variation in 
 amount of lime in the two papers is liable to cause 
 serious error. Moreover, experiments made by 
 the writer indicate that though two filter-papers 
 are treated by the same liquid they do not always 
 change the same. 
 
 Why, in estimating morphine in tincture of 
 
ALKALOIDS. 135 
 
 opium, is the tincture evaporated? To get rid 
 of the alcohol, and to concentrate the hquid. 
 
 Why, in estimating morphine in laudanum, is 
 water added to the concentrated tincture? To 
 precipitate resinous matter. 
 
 Why, in estimating morphine in laudanum, does 
 a precipitate sometimes form on evaporating the 
 filtrate to the 14 grams? The precipitate is 
 probably narcotine. Narcotine exists in opium 
 loosely combined with an acid, and the heat during 
 evaporation decomposes the salt, liberating nar- 
 cotine which is insoluble in water. 
 
 Why is morphine more bitter when combined with 
 a common acid than when free? It is more soluble. 
 
 Why does morphine acetate become less soluble with 
 age? It loses acetic acid, leaving the free alkaloid. 
 
 Why should the solution of ferric chloride used 
 in testing morphine be nearly neutral? Any excess 
 of acid destroys or prevents the coloration. 
 
 Why does Froehde's reagent (ammonium molyb- 
 date in sulphuric acid) give a blue color with mor- 
 phine? Morphine reduces molybdic acid to lower 
 oxides of the metal. 
 
 Why does iodic acid with starch and morphine 
 give a blue color? Morphine reduces iodic acid, 
 liberating iodine which gives a blue compound with 
 starch. 
 
 Why was the alkaloid narcotine given that name? 
 It was thought at first to be the narcotic principle 
 of opium. 
 
136 WHYS IN PHARMACY. 
 
 Why is the finding of meconic acid of any impor- 
 tance in a case of toxicology? It indicates that 
 opium and not pure morphine was taken. 
 
 Why is the gravimetric method of assaying aconite 
 objectionable? Aconite contains several alkaloids 
 that can be put into two classes, the aconitine 
 alkaloids and the aconine alkaloids, the former 
 being active and the latter nearly inert. The aconi- 
 tine alkaloids are converted to some extent into 
 the aconine compounds in drying the drug, and 
 by heat and alkahes during the process of assay; 
 and though a large amount of alkaloids are obtained 
 a variable proportion of them is inert. 
 
 Wliy should the use of aconitine be discouraged? 
 The commercial article is extremely variable, and 
 absolute aconitine is one of the most active of drugs. 
 
 Why does the U. S. P. direct that the containers 
 for apomorphine hydrochloride be previously rinsed 
 with hydrochloric acid? Glass bottles are fre- 
 quently sufficiently alkahne to render the contents 
 somewhat alkaline, and this tends to decomiDose 
 the apomorphine. 
 
 Why is no acid used in assaying colchicum? 
 The alkaloid is easily decomposed by acids, often 
 forming colored compounds. The acid is not neces- 
 sary as the alkaloid is soluble in about 22 parts of 
 water. 
 
 Why is acid added to the ethereal solution before 
 evaporating in assaying conium? To pi-event the 
 vaporization of coniine, which is a volatile alkaloid. 
 
ALKALOIDS. 137 
 
 Why is hydras tine called " white alkaloid"? In 
 order to distinguish it from berberine, the " yellow 
 alkaloid ''. Berberine was separated before hydras- 
 tine, and it was first called hydrastine. 
 
 Why is pilocarpine preferable to pilocarpus? It 
 is more uniform in strength. Pilocarpus contains 
 another alkaloid, jaborine, which is antagonistic to 
 pilocarpine. 
 
 Why does physostigma vary so much in activity? 
 It contains two alkaloids, physostigmine and cala- 
 barine, which vary in proportion and are antago- 
 nistic to each other. 
 
 Why is sodium bicarbonate used instead of ammo- 
 nia in assaying physostigma? The bicarbonate is 
 less alkaline and physostigmine is easily decomposed 
 by alkalies, forming colored compounds. 
 
 Why is ether added to the solution just before 
 titrating back the excess of acid in assaying physo- 
 stigma? The indicator, iodeosin, acts better in the 
 presence of ether. 
 
 Why is a trace of hypophosphorous acid some- 
 times added to a solution of physostigmine salicylate? 
 Unless protected the solution soon becomes red- 
 blue, due to the formation of rubeserin. One part 
 of dilute hypophosphorous acid to five hundred of 
 solution is said to be sufficient to keep it. 
 
 Why should the use of official veratrine be dis- 
 couraged? It is a mixture of alkaloids and varies 
 in proportion to its different ingrejdients. 
 
PRESCRIPTIONS. 
 
 Why should prescriptions be written in Latin? 
 (1) It is a language understood throughout the 
 world. (2) It is a dead language, and therefore is 
 not changing. (3) Common names vary in different 
 parts of the country, while Latin ones are distinctive. 
 (4) Technical Latin is not usually understood by 
 the patient, and so there is not the danger of arousing 
 prejudice. (5) The tendency to self-medication is 
 not increased. 
 
 Why should the physician sign his full name to 
 a prescription and not simply his initials? It some- 
 times happens that the prescriber has made a mis- 
 take, or for other reasons the compounder wants to 
 communicate with the writer, and in a large town 
 the prescription may be carried to a part where the 
 prescriber is not known. 
 
 Why is "J^^' placed at the head of prescription 
 blanks? It stands for the verb " recipe,'' meaning 
 to take. Originally the sign of Jupiter, n, was 
 used as a prayer asking for healing. 
 
 Why do many pharmacists write the label before 
 
 138 
 
PRESCRIPTIONS. 139 
 
 filling the prescription? The label has time to 
 become thoroughly dry, and they have time to con- 
 sider the best way of filling it. 
 
 Why should the pharmacist notice carefully the 
 doses of all strong medicines when they are pre- 
 scribed? The physician is human and liable to 
 make an error. In law the pharmacist as well as 
 the physician is held responsible in case injury 
 results from an overdose, and suit for damages is 
 more likely to be brought against the pharmacist 
 than the physician. 
 
 Why should the directions, " Use as directed," be 
 avoided by the prescriber? The patient is gen- 
 erally in a more or less nervous condition and likely 
 to forget the details. Then, too, by having the 
 directions on the prescription it makes another 
 safeguard in that the pharmacist can more readily 
 detect an error if present. Upon the dose depends 
 the safety. 
 
 Why is there a direct loss in buying such chemi- 
 cals as morphine and strychnine in one eighth 
 ounce bottles and selling it by the grain unless 
 the price is advanced more than enough to cover 
 the apparent cost of selling? The substance is 
 bought by avoirdupois weight, which has only 
 54.7 grains in one eighth of an ounce, while it is 
 sold by apothecary weight, which has 60 grains in 
 an eighth of an ounce. 
 
 Why is there a loss in buying quinine sulphate 
 in bulk and retaiUng it in small amounts? Tliis 
 
140 WHYS IN PHARMACY. 
 
 salt loses a considerable amount of water of crystal- 
 lization, and more quinine is sold for a given weight 
 than is bought. 
 
 Why should heat not be generally used in making 
 solutions at the prescription counter? Heat may 
 volatilize or decompose some ingredient or make a 
 supersaturated solution that will deposit large crys- 
 tals on cooling. 
 
 Why is it usually preferable, in mixing an insoluble 
 substance with a liquid, to rub it in the mortar with 
 a small amount of liquid first? If the solid is simply 
 put into a bottle and shaken the substance may 
 ''lump" and require time and agitation in order to 
 get it mixed. This is particularly true with calomel, 
 magnesia, sulphur, or a vegetable drug. 
 
 Why is it frequently preferable, in mixing solu- 
 tions that will precipitate, to have the solutions cold 
 and as dilute as possible before mixing them? The 
 precipitate will be finer, lighter, and more easily dif- 
 fused through the liquid. 
 
 Why should heat not be used in making solutions 
 of alkali bi carbonates? Heat decomposes them, 
 liberating carbon dioxide and leaving the normal 
 carbonate. 
 
 Why should ammonium carbonate be dissolved in 
 the cold? Heat volatilizes ammonia and carbon 
 dioxide. 
 
 Why is it generally best, when necessary to mix 
 them, to add an alcoholic solution of a substance in- 
 soluble in water, to the water, rather than the water 
 
PRESCRIPTIONS. 141 
 
 to the alcohol? The substance is precipitated in a finer 
 form and is more easily diffused. However, in some 
 cases where there is a comparatively large amount of 
 alcohol, and a small amount of precipitation, it is 
 better to add the water to the alcoholic solution. 
 
 Why should a stock solution of mercuric chloride 
 contain a little ammonium chloride? Ammonium 
 chloride prevents the reduction that slowly takes 
 place in a solution of pure mercuric chloride. 
 
 Why does ammonium chloride make mercuric chlo- 
 ride more soluble? Probably because a more soluble 
 double compound is formed. 
 
 Why is citric or tartaric acid sometimes added to 
 mercuric chloride tablets? To render the solution 
 made from them more penetrating, by preventing the 
 formation of an insoluble compound with albumin. 
 
 Why should potassium iodide not be kept long in 
 stock solution? Iodine is liberated. This can be 
 prevented to some extent by the presence of an alkali 
 carbonate, but this is often objectionable. 
 
 Why should bicarbonates of alkalies not be kept 
 in stock solutions? They lose carbon dioxide and 
 become more alkaline. 
 
 Why should chloral hydrate not be kept in stock 
 solution? It decomposes, becoming acid. 
 
 Why cannot hypodermic solutions be rendered 
 aseptic by heat? Those medicinal substances which 
 are usually administered hypodermically are more or 
 less decomposed by heat. 
 
 Why cannot alcohol be used as a preservative for 
 
142 WHYS IN THARMACY. 
 
 hypodermic solutions? Comparatively large amounts 
 of alcohol would be necessary to accomplish the pur- 
 pose, and alcohol, when injected, is an irritant and 
 astringent. 
 
 Why should mucilage of acacia not be used to sus- 
 pend insoluble substances in lotions? It leaves the 
 skin sticky or hard. Tragacanth is less objectionable, 
 as a much smaller amount will serve the same pur- 
 pose. 
 
 Why are acacia and tragacanth objectionable in 
 suspending bismuth subnitrate in a liquid? Traga- 
 canth seems to combine with the bismuth salt, form- 
 ing a curdy precipitate. When acacia is used and 
 the bismuth settles, it is difficult and sometimes im- 
 possible to shake up. Scoville suggests the use of 
 tragacanth with the addition of a little alcohol. 
 
 Why should eye-washes and hypodermic solutions 
 be filtered? To be sure that no solid matter is left 
 that would cause irritation. 
 
 Why cannot as much of certain powdered salts, 
 such as alum or Rochelle salt, be dissolved in water 
 as is the case with crystals? In the powdered con- 
 dition the salt has lost some of its water of crystalliza- 
 tion, and there is consequently more of the salt proper 
 in a given weight than is the case with the crystals. 
 
 Why should such substances as calomel and ipecac 
 be very finely divided? The finer the powders the 
 more active they seem to be. 
 
 Why should the following substances not be dis- 
 pensed in the form of a powder: Carbolic acid, cal- 
 
PRESCRIPTIONS. 143 
 
 cium bromide, iron and ammonium citrate, potas- 
 sium acetate, potassium carbonate, potassium hypo- 
 phosphite, sodium hypophosphite, potassium iodide 
 sodium iodide, strontium bromide, granular efferves- 
 cing salts, and sodium bromide? They are hygro- 
 scopic or deliquescent. 
 
 Why should the following substances not be dis- 
 pensed in the form of powders: Ferrous sulphate, 
 lead acetate, sodium carbonate, sodium sulphate, 
 sodium phosphate, and zinc acetate? They lose 
 water of crystallization and become more concen- 
 trated. 
 
 Why should the following substances not be dis- 
 pensed in the form of powders : Ammonium carbonate, 
 chloral, lead acetate, camphor, the iodides of mer- 
 cury, and the salts of silver? Ammonium carbonate 
 loses ammonia and carbon dioxide; chloral is irri- 
 tating; lead acetate loses acetic acid and becomes 
 insoluble; the iodides of mercury darken; camphor 
 volatilizes; and the silver salts are reduced. 
 
 Why should the following substances not be pre- 
 scribed together in the form of powders: Antipyrine 
 with carbolic acid, resorcin, or thymol; camphor with 
 carbolic acid, chloral hydrate, menthol, naphtol, re- 
 sorcin, salol, or thymol; chloral with euphorin, exal- 
 gin, phenacetin, menthol, salol, or thymol? They 
 liquefy or form soft masses. 
 
 Why is it that a good many crystalline compounds 
 liquefy when rubbed together? Heat of trituration 
 may be sufficient to start chemical reaction, forming 
 
144 WHYS IN PHARMACY. 
 
 liquid compounds in some cases, and water of crys- 
 tallization may be liberated in other cases. 
 
 Why should chlorates, permanganates, silver oxide 
 chromates, or nitrates not be rubbed with organic 
 matter or other reducing matter? Because the 
 liberation of a large amount of gas will cause an 
 explosion. 
 
 Why should solutions containing potent substances 
 like strychnine be filtered before dispensing? To be 
 certain that none is left undissolved, avoiding danger 
 of an overdose at the last of the prescription. 
 
 Why is the presence of alcohol often advisable when 
 an alkaloid salt is prescribed with other compounds? 
 A large number of compounds precipitate alkaloids; 
 alcohol frequently prevents this precipitation. 
 
 Why should a mixture of mercuric chloride and po- 
 tassium iodide not be given with an aqueous solution 
 of an alkaloidal salt? Mercuric chloride and potassium 
 iodide cause the formation first of mercuric iodide and 
 potassium chloride. Then the mercuric iodide com- 
 bines with more potassium iodide, forming Mayer's 
 reagent (potassium mercuric iodide), which precipi- 
 tates alkaloids. Even when the precipitated alkaloid 
 is harmless, the mixture may be dangerous on account 
 of the mercuric compound which is precipitated. 
 
 Why is more carbon dioxide given off when a car- 
 bonate is mixed with a solution of a salt of tin, anti- 
 mony, ferric iron and aluminium than when mixed 
 with salts of other metals (not considering the pres- 
 ence of a free acid)? The carbonate forms hydrox- 
 
PRESCRIPTIONS. 145 
 
 ides or oxides with these metalhc salts, practically all 
 of the carbon dioxide being ehminated. With the 
 other metallic salts it forms a normal or basic car- 
 bonate. 
 
 Why is honey a good addition to mixtures calling 
 for tincture of myrrh and aqueous solutions? Water 
 usually precipitates resin of myrrh in a form that 
 soon sticks together and adheres to the sides of the 
 bottle. Honey does not prevent precipitation, but 
 holds the resin in a flocculent condition, so that it is 
 easily suspended. 
 
 Why is a mixture of lead water and laudanum a 
 poor combination pharmaceutically ? Lead subace- 
 tate combines with sulphuric acid, meconic acid, and 
 the alkaloids in opium, forming insoluble compounds 
 with all of them. 
 
 Why does effervescence take place when ammo- 
 nium carbonate is added to syrup of garlic, ipecac, 
 or squill? These syrups contain free acetic acid, 
 which reacts with the carbonate. 
 
 Why does the variation in the order of mixing 
 potassium chlorate, hydrochloric acid, and water 
 cause a variation in color? Adding hydrochloric 
 acid to the chlorate and then adding water gives a 
 yellow-green solution, due to the chlorine formed. 
 Adding water to the chlorate or to hydrochloric 
 acid, and then adding the remaining ingredient, 
 gives a colorless solution. There is not nearly as 
 much chlorine formed by this as by the first method. 
 
 Why should glycerin be added to a mixture of 
 
146 WHYS IN PHARMACY. 
 
 carbolic acid and water when the proportion of 
 acid to water is much greater than 1 to 15? Car- 
 bohc acid separates from the mixture when the pro- 
 portion is much above this, and the glycerin pre- 
 vents separation. 
 
 Why should care be used in prescribing antipy- 
 rine in combination with other compounds? Anti- 
 pyrine resembles alkaloids in its precipitations, being 
 thrown out of solution by about the same substances 
 that precipitate alkaloids. 
 
 Why does a mixture of fluid extract of gelsemium, 
 chloral hydrate, antipyrine, and water separate 
 into layers? Antipyrine and chloral hydrate form 
 one or more chloral-antipyrines which are liquid 
 at first but may become solid. One of these com- 
 pounds is hypnal. Antipyrine liquefies with quite 
 a large number of compounds. 
 
 Why should gold and sodium chloride not be 
 put into the same prescription with potassium 
 iodide? Decomposition takes place, with the for- 
 mation of different compounds, depending on the 
 excess of the one or the other salt. Potassium iodide 
 is usually in excess and auric iodide is formed, chang- 
 ing to aurous iodide. 
 
 Why should ichthyol not be given with anything 
 that is acid? Acids combine with ammonia in 
 ichthyol and precipitate ichthyosulphonic acid as a 
 dark, resinous, adhesive mass. 
 
 Why is spirit of nitrous ether and potassium 
 iodide a dangerous combination? Iodine is liber- 
 
prescriptions: 147 
 
 ated and oxides of nitrogen are given off. The 
 presence of an acid increases the reaction, while an 
 alkali diminishes or retards it. 
 
 Why does spirit of nitrous ether give a green 
 color with antipyrine? The green isonitroso-anti- 
 pyrine is formed and is precipitated from concen- 
 trated solutions. The compound is not now 
 regarded as poisonous. Alkali carbonates retard 
 the reaction. 
 
 Why should prescriptions calling for spirit of 
 nitrous ether and drugs containing considerable 
 tannic acid not be dispensed as soon as they are 
 mixed? Tannic acid decomposes ethyl nitrite or 
 nitrous acid, liberating oxides of nitrogen. The 
 reaction may take place slowly, and if the bottle 
 is stoppered, sufficient pressure may be formed to 
 burst it. 
 
 Why does an effervescence occur when spirit of 
 nitrous ether is added to a solution of potassium 
 acetate or other similar soluble salt? The efferves- 
 cence is probably due to the throwing of the ethyl 
 nitrite out of solution, when it is easily volatihzed. 
 
 Why does a mixture of spirit of nitrous ether, 
 potassium citrate, and water separate into two 
 layers? Potassium citrate has a strong affinity for 
 water and is insoluble in alcohol. Alcohol tends 
 to throw it out of solution, but it retains enough 
 of water to keep it a liquid. 
 
 Why is a mixture of ammonium acetate and 
 spirit of nitrous ether a good combination? Because 
 
148 WHYS IN PHARMACY. 
 
 as soon as the nitrous radical is liberated from ethyl 
 nitrite it combines with the annnonia of ammo- 
 nium acetate and forms ammonium nitrite^ which 
 is nearly as active. 
 
 Why is an amber bottle better than a blue bottle 
 for silver nitrate solutions? It gives protection 
 from the light as well, and the contents can be 
 more readily seen. 
 
 Why should sodium phosphate not be given with 
 alkaloidal or neutral metallic salts? The official 
 phosphate is a little alkaline and liberates the alka- 
 loid or forms an insoluble compound with the metal. 
 When prescribed in such combination it should 
 first be neutralized. 
 
 Why does an alkali citrate increase the solu- 
 bility of benzoic and salicylic acids? A partial 
 decomposition probably results and some alkali 
 benzoate and salicylate are formed; and these, as 
 well as the citric acid liberated, are soluble in water. 
 
 Why does an alkali citrate often increase the solu- 
 bility of a metallic salt? Alkali citrates often form 
 double compounds with metallic salts and such 
 compounds are soluble. 
 
 Why does a mixture of borax and zinc sulphate 
 liquefy when rubbed together? Both salts contain 
 large amounts of water of crystallization which is 
 liberated by the chemical reaction induced by the 
 rubbing. 
 
 Why will one compounder get a white precipitate, 
 and another one a clear solution, in filling a pre- 
 
PRESCHIPTIONS. 149 
 
 scription calling for magnesium carbonate, IJ dr.; 
 borax and citric acid, each 2 dr.; water, enough to 
 make 8 fl. oz.? By adding the carbonate to the 
 acid and water, a clear solution results from which 
 borax causes no precipitation. By adding borax 
 to acid and water, a clear solution results, but the 
 carbonate does not dissolve in it because the borax 
 largely neutralizes the acid. 
 
 Why does the addition of hydrocyanic acid to a 
 mixture of codeine, tincture of iodine, and water 
 dissolve the precipitate and give a colorless solu- 
 tion? The precipitate present is a compound of 
 iodine and codeine, and the color is due to 
 iodine. Hydrocyanic acid reduces iodine to an 
 iodide, thus destroying the color and breaking up 
 the precipitate. 
 
 Why does a mixture of silver nitrate, cocaine, 
 and water give a black precipitate? Cocaine takes 
 away the nitric acid, precipitating silver as the oxide. 
 If cocaine hydrochloride is used a white precipitate 
 of silver chloride is formed. Cocaine nitrate should 
 be used.. 
 
 Why should quinine sulphate be rubbed in a 
 mortar before being put into capsules? It becomes 
 less bulky. 
 
 Why does quinine sulphate, potassium acetate, 
 and water make a thick mixture? Reaction takes 
 place and quinine acetate is probably formed, 
 although some recent experimenters claim that 
 quinine hydrate, acetic acid, and potassium sul- 
 
150 WHYS IN PHARMACY. 
 
 phate are formed, and it is the quinine hydrate that 
 makes the mixture so nearly sohd. 
 
 Why should care be used in combining quinine 
 sulphate and potassium iodide in the same mixture? 
 Quite frequently an acid is present, and if so it dis- 
 solves the quinine sulphate. Potassium iodide pre- 
 cipitates a concentrated solution of a quinine salt. 
 The acid hberates hydriodic acid, which is easily 
 oxidized by the air, liberating iodine. Iodine gives 
 a purphsh-red precipitate with quinine. 
 
 Why, in mixing a carbonate or hydroxide with 
 quinine sulphate, should the solutions be dilute and 
 cold? The free alkaloid will be liberated, and unless 
 precipitated under the above conditions it is likely 
 to come down as a sticky mass. 
 
 Why do two substances precipitate when sodium 
 benzoate is added to an acid solution of quinine 
 sulphate? Quinine benzoate is precipitated, and 
 benzoic acid is liberated and precipitated. 
 
 Why does the addition of quinine sulphate to 
 tincture of the chloride of iron sometimes give a 
 yellow-brown precipitate? Quinine sulphate takes 
 up the free acid to form a soluble compound and 
 so weakens the acid of the tincture that a basic 
 chloride of iron is precipitated. The addition of 
 more acid prevents this precipitation. 
 
 Why is quinine bisulphate better than the sul- 
 phate in making pills? It is less bulky. 
 
 Why should acid not be used to get quinine 
 sulphate into solution when fluid extract of licorice 
 
PRESCRIPTIONS. 151 
 
 is used to cover up the bitter taste? The acid 
 breaks up the ammonium glycyrrhizate and destroys 
 the sweet taste, precipitating the bitter glycyrrhizic 
 acid. It is better to leave out the acid and dis- 
 pense the prescription as a shake mixture. 
 
 Why does a mixture of glycerin, borax, and water 
 give an acid solution? Borax and glycerin combine to 
 form sodium metaborate and glyceryl borate. The lat- 
 ter compound is decomposed by water, forming glyce- 
 rin and boric acid; the solution is thus made acid. 
 
 Why does borax precipitate neutral solutions of 
 metallic and alkaloidal salts? Borax is quite strongly 
 alkaline and causes precipitation on this account. 
 Sometimes the addition of a little glycerin is allow- 
 able and will prevent precipitation. 
 
 Why does a mixture of mercuric chloride and tar- 
 tar emetic give a white precipitate? Tartar emetic 
 reduces mercuric chloride to calomel. 
 
 Why does a mixture of sodium bromide, antipyrine, 
 camphor, and caffeine citrate, when put into capsules, 
 liquefy the capsule ? The chief ingredient concerned 
 is sodium bromide which absorbs sufficient water to 
 cause the trouble. Some drying powder should be 
 used. 
 
 Why does a mixture of sodium salicylate, citrated 
 caffeine, antipyrine, and syrup of orange give a white 
 precipitate? In a strong solution sodium salicylate 
 may precipitate antipyrine, and the citric acid in 
 citrated caffeine liberates salicylic acid, which is only 
 sparingly soluble. 
 
152 WHYS IN PHARMACY. 
 
 Why should bismuth subnitrate and a carbonate or 
 bicarbonate not be prescribed together in aqueous 
 mixture? Water hberates nitric acid from the bis- 
 muth salt, making a more basic salt; and the nitric 
 acid in turn liberates carbon dioxide. The bismuth 
 salt is converted into a basic bismuth carbonate 
 The evolution of carbon dioxide is slow and may be 
 sufficient to burst the bottle after it has been received 
 by the patient. These reactions may be hurried by 
 warming the mixture. Some dispensers use bismuth 
 subcarbonate at once instead of waiting for it to be 
 formed as the result of the reaction. 
 
 Why does a change in the color of the precipitate 
 occur when bismuth subnitrate and potassium iodide 
 are mixed with water? Different basic iodides of 
 bismuth are formed, varying in color from brown to 
 red and gray. 
 
 Why does bismuth subnitrate, when mixed with 
 potassium hypophosphite and water, change in color? 
 The hypophosphite reduces the bismuth, forming 
 black insoluble compounds. 
 
 Why does an acid, when added to a solution of bis- 
 muth and ammonium citrate, give a white precipi- 
 tate? The acid combines with the ammonia and 
 sets free the insoluble bismuth citrate. 
 
 Why is difficulty experienced in making supposi- 
 tories containing chloral hydrate? Chloral hydrate 
 seems to have a liquefying action on oil of theobroma 
 somewhat similar to its action on camphor. Several 
 other compounds have a similar effect. 
 
PRESCRIPTIONS. 153 
 
 Why does a mixture of alcohol, chloral hydrate, 
 and water sometimes separate into two layers and 
 sometimes not? Chloral hydrate combines with al- 
 cohol, forming chloral alcoholate; this is soluble in 
 alcohol, but not in water, and is somewhat soluble in 
 a mixture of alcohol and water. If chloral is present 
 in comparatively large amounts, and alcohol in small 
 amounts, there is more danger of separation. Solu- 
 ble salts, such as potassium bromide, tend to cause 
 separation. 
 
 Why should scale salts of iron not be powdered 
 before being dissolved in water? It makes the pow- 
 dered salt form a sticky mass that dissolves slowly. 
 Warm water is better than cold. Boihng water may 
 reduce the ferric to ferrous to some extent. 
 
 Why should scale salts of iron not be shaken much 
 with water? A foam is formed that is quite per- 
 sistent. 
 
 AVhy is it necessary to add but little water when 
 sulphate of iron and potassium bromide are rubbed 
 together in making pills of ferrous bromide? Reac- 
 tion takes place, liberating a considerable amount of 
 water of crystallization. 
 
 Why does iodine lose its therapeutic effect when it 
 is given with drugs containing much tannic acid? In 
 the presence of water iodine combines with some 
 tannic acid and with the hydrogen of the water. The 
 oxygen of the water makes an insoluble compound 
 with more tannin. 
 
 Why does a mixture of iodine and ammonia not 
 
154 WHYS IN PHARMACY. 
 
 have the same effect that they do when apphed sepa- 
 rately? Iodine combines with anmionia, forming 
 chiefly ammonium iodide with a little iodate. Ex- 
 plosive iodide of nitrogen is formed under certain 
 conditions. 
 
 Why should iodine not be given with oil of turpen- 
 tine? If the two are mixed together violent chemical 
 reaction results. Moreover, the iodine probably does 
 not have the same effect therapeutically as before. 
 
 Why should Fowler's solution be neutralized pre- 
 vious to mixing with a solution of a ferric salt? It 
 is alkaline, and if present in sufficient amount it will 
 precipitate ferric hydroxide, which will in turn pre- 
 cipitate potassium arsenite. 
 
 Why should Fowler's solution not be prescribed 
 with a solution of mercuric chloride? It reduces 
 mercuric chloride to calomel, and if present in suffi- 
 cient amount, to metallic mercury also. Acidifying 
 the Fowler's solution will prevent this. 
 
 Why should Fowler's solution not be prescribed 
 with a solution of an alkaloidal salt? Being alka- 
 line, it liberates the alkaloid which is precipi- 
 tated. Fowler's solution should be neutralized 
 before using. 
 
 Why does citric acid prevent the precipitation of 
 iron salts by ammonium hydroxide? It forms double 
 compounds which are soluble. 
 
 Why does phosphoric acid prevent the black color 
 which usually results in combining tannic acid and a 
 ferric salt? Phosphoric acid seems to have a stronger 
 
PRESCRirTlONS. 155 
 
 affinity for iron than tannic acid has, and thus dis- 
 places it. 
 
 Why should tincture of ferric chloride and potas- 
 sium iodide never be given in the same prescription? 
 Iodine is liberated, and if all of the iodide is decom- 
 posed, iodine will be precipitated. Ferric chloride is 
 reduced to ferrous chloride. 
 
 Why are syrup of iodide of iron and potassium 
 chlorate dangerous when prescribed together? Iodine 
 is liberated even in neutral mixtures. Adding a httle 
 ammonia prevents this liberation for a time only and 
 will cause precipitation of the iron. 
 
 Why do dilute solutions of carbohc acid and ferric 
 salts sometimes fail to give a violet coloration? Or- 
 ganic matter and some neutral salts interfere. 
 
 Why should mucilage of acacia and solution or 
 tincture of ferric chloride be well diluted before being 
 mixed? Ferric salts will gelatinize mucilage of acacia 
 unless in dilute solutions. Alkali citrates prevent 
 gelatinization. 
 
 Why may alkali hydroxides or carbonates be given 
 with ferric chloride without apparent incompatibihty 
 if sugar, glycerin, citrates, tartrates and some other 
 substances are present? Because these substances 
 hold ferric hydroxide in solution. 
 
 Why does phosphoric acid precipitate a solution of 
 soluble phosphate of iron? Soluble phosphate of 
 iron may be a double compound of ferric phosphate 
 and sodium citrate, or it may be a mixture of these, 
 the ferric phosphate being soluble in the citrate. 
 
156 WHYS IN PHARMACY. 
 
 Phosphoric acid may break up the double compound 
 or then decompose sodium citrate, forming a com- 
 pound which no longer acts as a solvent. The remedy 
 is to use metaphosphoric acid, free from ortho- or 
 pyro-acid, in the place of the official acid. Strong 
 official phosphoric acid will also dissolve the precipi- 
 tate. Sometimes dilute phosphoric acid will not 
 cause precipitation. 
 
 Why does calomel with potassium hypophosphite 
 turn dark? Because the hypophosphite reduces the 
 calomel to metafile mercury. 
 
 Why does a mixture of soap and calomel turn dark? 
 Soap is alkaline and hence causes the formation of 
 some black oxide of mercury. 
 
 Why must calomel and potassium iodide not be 
 given together unless the calomel is in small amounts? 
 Potassium iodide with calomel first forms mercurous 
 iodide and potassium chloride. Mercurous iodide, 
 with more potassium iodide, is decomposed, forming 
 mercuric iodide and metafile mercury. Mercuric 
 iodide combines with more potassium iodide, forming 
 the nearly colorless and soluble potassium-mercuric 
 iodide, which is as active as mercuric chloride. 
 
 Why should antipyrine not be given with calomel? 
 Part of the calomel is changed to metallic mercury, 
 and part is changed to the mercuric salt, which is 
 active. This reaction is more fikely to take place in 
 the presence of sodium bicarbonate. 
 
 Why should glycerin be diluted before applying to 
 the hands? It is hygroscopic and absorbs moisture 
 
PRESCRIPTIONS. 157 
 
 from the skin if it is not diluted, making the skin hard 
 and rough. 
 
 Why should castor oil not be taken with oleoresin 
 of male fern? It seems to increase the absorption of 
 filicic acid and may cause symptoms of poisoning. 
 
 Why is it best to spread a little olive oil over the 
 surface of a linseed poultice? It prevents the 
 poultice from becoming hard and sticking to the 
 skin. 
 
 Why should preparations of iron be taken through 
 a glass tube? Most preparations of iron contain 
 acid which acts on the enamel of the teeth. There 
 is often a little sulphide around the teeth and this 
 gives a sulphide of iron which darkens the teeth. 
 
 Why is ferric hydroxide not precipitated from 
 ferric salts in the alkaline contents of the intestine? 
 The gases and the organic matter present keep it 
 in solution. 
 
 Why should arsenic be given after a meal? So 
 as to dilute it with the food and prevent its irritating 
 effect. 
 
 Why is the administration of calomel often fol- 
 lowed by a dose of black draught? Calomel acts 
 on the upper portion of the intestine and black 
 draught on the lower portion. 
 
 Why does the administration of most organic 
 acids render the urine alkaline? The acids are 
 eliminated in the urine as carbonates. 
 
 Why does benzoic acid make the urine acid? 
 It is eliminated in the urine as hippuric acid. 
 
158 WHYS IN PHARMACY. 
 
 Why is iodoform an antiseptic when used in 
 dinics but not when experimented with in the 
 test-tube? Apphed to the hving tissue it is prob- 
 ably dissolved by the fluids and decomposed by 
 the living cells. In the test-tube these conditions 
 do not exist. 
 
 Why should prescriptions containing chloral, mor- 
 phine, or cocaine never be refilled without the phy- 
 sician's consent? There is danger of the patient 
 forming a habit. 
 
 Why are morphine and atropine sometimes given 
 together although they are somewhat antagonistic 
 in physiological action? When given together the 
 atropine is in small amounts, and in such a com- 
 bination it relieves indigestion and cardiac depression. 
 
 Why are direct emetics of but little service in 
 cases of poisoning by anaesthetics, such as carbolic 
 acid and cocaine? Direct emetics act by irritating 
 the walls of the stomach, and if the walls are anaes- 
 thetized they will have but little effect. 
 
 Why should the stomach-pump be used with 
 care, if used at all, in cases of poisoning by alkalies 
 or acids? Alkalies and acids often corrode the walls 
 of the esophagus, weakening it, so that there is dan- 
 ger of puncturing it with the tube of the pump. 
 
 Why should oils not be given as demulcents after 
 phosphorus poisoning? Oils aid the solution and 
 the action of phosphorus. Old oil of turpentine 
 has been recommended because it contains ozone, 
 which has an oxidizing effect on the phosphorus. 
 
PRESCRIPTIONS. 159 
 
 Why is charcoal used as an antidote for poison- 
 ing by alkaloids, phosphorus, and many metallic 
 salts? It has the property of absorbing these sub- 
 stances and holding them. 
 
 Why are sulphates given in case of poisoning by 
 carbolic acid? They convert the acid into sulpho- 
 carbolates which are much less poisonous. 
 
 Why is alcohol given for poisoning by carbohc 
 acid? It antidotes the action of carbohc acid, but 
 it is not known whether it is a chemical or a physio- 
 logical antidote. 
 
 Why is albumin a good antidote for poisoning 
 by metallic salts? It forms insoluble compounds 
 with most metallic salts, but these should be removed 
 as quickly as possible as they are slowly absorbed. 
 In case of poisoning by corrosive subHmate too 
 much albumin redissolves the compound. 
 
MISCELLANEOUS. 
 
 Why do drops of liquids vary so much in size? The 
 size depends upon the shape and size of the vessel 
 from which dropped, upon adhesion, cohesion, rapid- 
 ity of flow, and viscosity. 
 
 Why is a drop of liquid from a curved eye-dropper 
 larger than one from a straight dropper having the 
 same size opening? The straight one is generally 
 held at an angle so that the drop falls from one side 
 of the orifice; but with a curved dropper the drop 
 falls from the whole circle of the orifice. 
 
 Why is the center of gravity of the beam of a bal- 
 ance below the fulcrum? If the two coincided the 
 beam would stay in any position in which it is placed. 
 If the center of gravity is above the fulcrum the 
 beam will tend to turn over. 
 
 Why is the center of gravity of the beam of a bal- 
 ance, compared with the fulcrum, lower in a balance 
 intended for heavy weights than it is in more delicate 
 balances? The nearer the center of gravity ap- 
 proaches the edge of the fulcrum the more accurate 
 will it be, the slower to oscillate, and the Hghter the 
 
 weight that will start it. 
 
 160 
 
MISCELLANEOUS. 161 
 
 Why is an agate knife-edge better than a steel one? 
 It is harder and does not corrode. 
 
 Why should a thermometer stand for two years 
 before being graduated? To allow time for the glass 
 to contract. 
 
 Why is mercury a good fluid for a thermometer? 
 It can be reduced to a comparatively low tempera- 
 ture without solidifying, will record a comparatively 
 high temperature, does not adhere to the sides of the 
 tube, possesses a uniform rate of expansion for each 
 increment of heat, and has great conducting power. 
 
 Why should the bulb of the thermometer be a 
 little above the liquid in determining the boiling- 
 point of the liquid? If placed in the liquid it will 
 not show the exact boiling-point. The liquid is gen- 
 erally a little hotter. 
 
 Why is the bumping of a hot liquid relieved by 
 putting in some irregular or angular substance? 
 Such a substance aids the liberation and evolution 
 of the vapor bubbles. 
 
 Why was the temperature of ^'25° C. " adopted in 
 the 8th revision of the U. S. P.? It comes nearer the 
 ordinary temperature than 15° C. and can be more 
 easily attained. 
 
 Why should a filter- paper never extend above the 
 edge of the funnel? Capillary attraction causes the 
 liquid to rise and crawl over the funnel; moreover, 
 the paper cannot be readily washed under such cir- 
 cumstances. 
 
 Why should attention be given in buying funnels 
 
162 WHYS IN PHARMACY. 
 
 to get those having an angle of sixty degrees? Many 
 funnels do not have that angle, and filter-paper folded 
 in the ordinary way makes an angle of sixty degrees. 
 
 Why is upward filtration sometimes preferable to 
 downward filtration? By making a liquid pass up- 
 ward through a filter, the solid matter does not be- 
 come packed on the filter so much and clog filtration. 
 
 Why is 4° C. specified as the temperature at which 
 1 cc. shall weigh 1 gram? At 4° C. water has its maxi- 
 mum density, a given volume being lighter when 
 either above or below 4° C. 
 
 Why does dissolving a solid in water produce cold? 
 Heat is absorbed; active heat is changed to latent 
 heat when a solid changes from such to a liquid con- 
 dition unless there be chemical reaction. 
 
 Why does the solution of anhydrous salts in water 
 produce heat? It is generally considered that chem- 
 ical reaction takes place, the water of crystallization 
 combining with the salt. 
 
 Why do some solids in dissolving produce more 
 cold than others? Generally the more rapid the solu- 
 tion the greater the amount of cold produced. 
 
 Why does dissolving a gas in water produce a rise 
 in temperature? When a gas changes to a Hquid, 
 latent heat is changed to active heat. 
 
 Why, in powdering a substance, is it better to 
 remove the finer particles by frequent sifting? If 
 the finer particles are left in they become more or 
 less packed around the larger ones and protect them 
 from being powdered. 
 
MISCELLANEOUS. 163 
 
 Why does powdering a soluble substance aid its 
 solution in a liquid? A greater surface is exposed to 
 the solvent action of the liquid. 
 
 Why does stirring aid solution? The liquid in im- 
 mediate contact with the solid becomes saturated, or 
 nearly so, and stirring causes this to be displaced by 
 liquid that is less saturated. 
 
 Why does heat generally aid solution? Heat causes 
 greater molecular motion, favors molecular separa- 
 tion, and causes currents to be formed in the liquid. 
 
 Why is albumin used in clarifying liquids? Be- 
 cause it can be intimately mixed with the liquid, and 
 then when it is coagulated it carries the suspended 
 matter down with it. 
 
 Why does heating sometimes clarify a Uquid? Heat 
 coagulates albumin if present, and this acts mechan- 
 ically in enveloping the suspended matter. Heat 
 lessens the viscosity of the hquid, allowing the mat- 
 ter to separate more readily. The sohd matter may 
 also be carried to the top by the globules of vapor 
 formed. 
 
 Why does fermentation sometimes clarify a liquid? 
 If albumin is present it is coagulated by the alcohol 
 and acid formed. 
 
 Why does rapidity of evaporation depend upon the 
 extent of surface exposed to the air when a liquid is 
 evaporated below its boiling-point? The formation 
 of vapor takes place at the surface which is exposed 
 to air. 
 
 Why does rapidity of evaporation depend upon the 
 
164 WHYS IN PHARMACY. 
 
 extent of surface exposed to heat when a liquid is 
 evaporated by boiling? The formation of vapor un- 
 der such circumstances takes place chiefly at the 
 surface exposed to heat. 
 
 Why do shallow ve^.sels favor evaporation? There 
 is less weight of liquid above the heat, and therefore 
 less resistance to the escape of bubbles. 
 
 Why are stone vessels better than glass for crys- 
 tallizing? The roughness of the surface favors crys- 
 tallization. 
 
 Why should a precipitating jar be wider at the 
 bottom than at the top? So that the precipitate on 
 settling will not adhere to the sides of the jar. 
 
 Why is a non-luminous flame hotter than a lumi- 
 nous flame? In a non-luminous flame all of the 
 carbon is consumed while it is not in a luminous 
 flame. 
 
 Why is the cold water made to enter the lower 
 opening of a Liebig condenser rather than the top? 
 As water becomes heated it naturally rises and the 
 cold water pushes it out instead of mixing with it. 
 The lower end of the condenser from which the con- 
 densed vapor flows is thus kept at the lowest tem- 
 perature possible. 
 
 Why is a worm condenser better than a straight 
 one? Sometimes in case of a straight condenser the 
 vapor passes through mthout touching the sides of 
 the tube and without condensing. In a worm con- 
 denser the vapor is made to continually change its 
 course and so come in contact with the cool tube. 
 
EQUATIONS SHOWING THE CHEMICAL RE- 
 ACTIONS WHICH TAKE PLACE IN MAKING 
 THE PREPARATIONS FOR WHICH THE 
 PHARMACOPCEIA GIVES DIRECTIONS. 
 
 Dilute Hydriodic Acid. 
 
 KI + 
 
 Potassium 
 iodide 
 
 H2C4H4O6 
 
 Tartaric acid 
 
 KH2PO2 + H2C4H4O6 
 
 Potassium Tartaric 
 
 hypophos- acid 
 
 phite 
 
 = HI + 
 
 Hydriodic acid 
 
 KHC4H4O6. 
 
 Potassium 
 bitartrate 
 
 = H3PO2 + KHC4H4O6. 
 
 Hypophos- 
 phorous 
 acid 
 
 Potassium 
 bitartrate 
 
 Dilute Hydrocyanic Acid. 
 AgCN + HCl = HCN + AgCl. 
 
 Silver 
 cyanide 
 
 Hydrochlo- 
 ric acid 
 
 Hydrocy- 
 anic acid 
 
 Silver 
 chloride 
 
 Nitrohydrochloric Acid. 
 
 HNO3 + 3HC1 = NOCl 
 
 Nitric 
 acid 
 
 2HNO3 
 
 Nitric 
 acid 
 
 Hydrochlo- 
 ric acid 
 
 Nitrosyl mono- 
 chloride 
 
 + CI2 
 
 Chlorine 
 
 + 
 
 2H2O. 
 
 Water 
 
 + 6HC1 = 
 
 Hydro- 
 chloric acid 
 
 2NOCI2 
 
 Nitrosyl 
 dichloride 
 
 + CI2 + 4H2O. 
 
 Chlorine Water 
 
 Probably both reactions take place. 
 
 165 
 
166 WHYS IN PHARMACY. 
 
 Aromatic Sulphuric Acid, 
 C2H5OH + H2SO4 = C2H5HSO4 + H2O; 
 
 Alcohol Sulphuric Ethyl acid Water 
 
 acid sulphate 
 
 and also, to some extent, 
 
 2C2H5OH + H2SO4 = (C2H5)20 + H2SO4 + H2O. 
 
 Alcohol Sulphuric Ether Sulphuric Water 
 
 acid acid 
 
 Sulphurous Acid. 
 
 4H2S04 
 
 + C2 = 
 
 4SO2 
 
 + 2CO2 + 4H2O 
 
 Sulphuric 
 acid 
 
 Carbon 
 
 Sulphur 
 dioxide 
 
 Carbon Water 
 dioxide 
 
 Aluminum Hydroxide, 
 
 Al2K2(S04)4 +3Na2C03 +3H2O = 
 
 Alum Sodium Water 
 
 carbonate 
 
 2A1(0H)3 +K2SO4 +3Na2S04 +3CO2. 
 
 Aluminum Potassium Sodium Carbon 
 
 hydroxide sulphate sulphate dioxide 
 
 Fused Silver Nitrate. 
 
 AgNOs + HCl = AgCl + HNO3. 
 
 Silver Hydro- Silver Nitric 
 
 nitrate chloric acid chloride acid 
 
 Bismuth Citrate. 
 BiONOs + H3C6H5O7 = BiCeHsOy + HNO3 + H2O. 
 
 Bismuth Citric acid Bismuth Nitric Water 
 
 subnitrate citrate acid 
 
EQUATIONS SHOWING CHEMICAL REACTIONS. 167 
 
 Sulphurated Lime. 
 
 CaS04 
 
 + 3C = 
 
 = CaS + 2C0 + CO2. 
 
 Calcium 
 
 Carbon 
 
 Calcium Carbon Carbon 
 
 sulphate 
 
 
 sulphide monoxide dioxide 
 
 Purified Animal Charcoal. 
 
 Ca3(P04)2 + 4HC1 = Ca(H2P04)2 + 2CaCl 
 
 Calcium Hydro- 
 
 phosphate chloric acid 
 
 Calcium acid 
 phosphate 
 
 Calcium 
 chloride 
 
 and 
 
 CaCOs + 2HC1 = CaCla + CO2 + H2O. 
 
 Calcium Hydro- Calcium Carbon Water 
 
 carbonate chloric acid chloride dioxide 
 
 Lead Plaster. 
 
 2NaCi8H3302 +Pb(C2H302)2 = 
 
 Sodium oleate Lead acetate 
 
 Pb(Ci8H3302)2 +2NaC2H302. 
 
 Lead oleate Sodium acetate 
 
 Saccharated Carbonate of Iron. 
 
 FeS04 + 2NaHC03 = reC03+ Na2S04+C02+H20. 
 
 Ferrous 
 sulphate 
 
 Sodium 
 bicarbonate 
 
 Ferrous 
 carbonate 
 
 Sodium 
 sulphate 
 
 Carbon Water 
 dioxide 
 
 Ferric Hydroxide. 
 
 Fe2(S04)3 +6NH40H = 2Fe(OH)3 +3(NH4)2S04. 
 
 Ferric 
 sulphate 
 
 Ammonia 
 
 Ferric 
 hydroxide 
 
 Ammonium 
 sulphate 
 
168 
 
 WHYS IN PHARMACY. 
 
 Glycerite of Boroglycerin. 
 C3H5(0H)3 +H3BO3 ^CsHsBOs +3H2O. 
 
 Glycerin Boric acid Glyceryl borate Water 
 
 Yellow Iodide of Mercury. 
 
 3Hg + 4HNO3 = 3HgN03 + NO + 2H2O. 
 
 Mercury Nitric acid Mercurous Nitric oxide Water 
 
 nitrate 
 
 HgN03 + KI = Hgl + KNO3. 
 
 Mercurous 
 nitrate 
 
 Potassium 
 iodide 
 
 Mercurous 
 iodide 
 
 Potassium 
 iodide 
 
 If potassium iodide is in excess the following 
 reactions take place: 
 
 2HgI + KI = Hg + Hgl2 + KI. 
 
 Mercurous 
 iodide 
 
 Potassium 
 iodide 
 
 Mercury 
 
 Mercuric 
 iodide 
 
 Potassium 
 iodide 
 
 Hgl2 
 
 Mercuric 
 iodide 
 
 + 2KI = Hgl2-2KI. 
 
 Potassium Potassium mercuric 
 iodide iodide 
 
 Red Iodide of Mercury. 
 
 HgCl2 
 
 Mercuric 
 chloride 
 
 + 2KI 
 
 Potassium 
 iodide 
 
 HgT2 + 2KC1. 
 
 Mercuric 
 iodide 
 
 Potassium 
 chloride 
 
 Hgl2 
 
 Mercuric 
 iodide 
 
 + 2KI = 
 
 Potassium 
 iodide 
 
 Hgl2-2KI. 
 
 Potassium 
 
 mercuric 
 
 iodide 
 
 8HgCl2 + 2KI = 
 
 Mercuric 
 chloride 
 
 Potassium 
 iodide 
 
 Hgl2-2HgCl2 + 2KC1. 
 
 Mercuric Potassiurn 
 
 iodochloride chloride 
 
 If too much potassium iodide is used the second 
 reaction takes place, and if tlie mercuric chloride is 
 in excess the last reaction takes place. 
 
EQUATIONS SHOWING CHEMICAL REACTIONS. 1G9 
 
 Yellow Oxide of Mercury. 
 HgCl2 + 2NaOH = HgO + 2NaCl + H2O. 
 
 Mercuric Sodium Mercuric Sodium Water 
 
 chloride hydroxide oxide chloride 
 
 4HgCl2 +6NaOH = HgCl2 • 3HgO +6NaCl +3H2O, 
 
 Mercuric Sodium Basic mercuric Sodium Water 
 
 chloride hydroxide chloride chloride 
 
 if HgCl2 is in excess. 
 
 Ammoniated Mercury. 
 HgCl2 + 2NH4OH = NH4CI + NH2HgCl + 2H2O. 
 
 Mercuric Ammonia Ammonium Ammoniated Water 
 
 chloride chloride mercury 
 
 Infusion of Wild Cherry. 
 C20H27NO11 +2H2O +emulsin = 
 
 Amygdalin Water 
 
 2C6H12O6 +HCN +C6H5COH +emulsin. 
 
 Glucose Hydrocy- Benzalde- 
 anic acid hyde 
 
 Ammonia Liniment. 
 
 C3H5(Ci8H3302)3 +3NH40H = 
 
 Olein Ammonia 
 
 3NH4C,«H3302 +C3H5(0PI)3, 
 
 Ammonium oleate Glycerin 
 
 and 
 
 HC18H3302 + NH40H = NH4C18H3302 + H20. 
 
 Oleic acid Ammonia Ammonium oleate Water 
 
 Solution of Arsenous Acid. 
 AS2O3 + 3H2O = 2H3ASO3. 
 
 Arsenous oxide Water Arsenous acid 
 
170 
 
 WHYS IN PHARMACY. 
 
 Solution of Ammonium Acetate. 
 
 NH4HCO3 • NH4NH2CO2 -f 3HC2H3O2 = 
 
 Acetic acid 
 
 Ammonium bicarbonate 
 and carbamate 
 
 3NH4C2H3O2 +2CO2 +H2O. 
 
 Ammonium 
 acetate 
 
 Carbon 
 dioxide 
 
 Water 
 
 Solution of Lime. 
 
 CaO + H2O = Ca(0H)2. 
 
 Lime 
 
 Water Calcium hydroxide 
 
 Compound Solution of Chlorine. 
 KCIO3 + 6HC1 = KCl + 3CI2 + 3H2O, 
 
 potassium 
 chlorate 
 
 Hydrochloric Potassium Chlorine Water 
 
 acid chloride 
 
 and 
 
 2KCIO3 + 4HC1 = 2KC1 + 2CIO2 + CI2 + 2H2O. 
 
 Potassium Hydrochloric Potassium Chlorine Chlorine Water 
 chlorate acid chloride peroxide 
 
 Solution of Ferric Chloride. 
 
 Fe + 2HC1 = FeCl2 + H^ 
 
 Iron 
 
 Hydro- 
 chloric acid 
 
 Ferrous 
 chloride 
 
 Hydrogen 
 
 3FeCl2 +HNO3 +3HC1 = 3FeCl3 +N0 +2H2O. 
 
 Ferrous Nitric Hydro- Ferric Nitric 
 
 chloride acid chloric acid chloride oxide 
 
 Water 
 
 Solution of Iron and Ammonium Acetate. 
 
 FeCls +3NH4C2H302 = Fe(C2H302)3 +3NH4CI. 
 
 Ferric 
 chloride 
 
 Ammonium 
 acetate 
 
 Ferric 
 acetate 
 
 Ammonium 
 chloride 
 
 (To some extent.) 
 
EQUATIONS SHOWING CHEMICAL REACTIONS. 171 
 
 Solution of Ferric Subsulphate. 
 12FeS04 +3H2SO4 +4HNO3 = 
 
 Ferrous Sulphuric Nitric 
 
 sulphate acid acid ♦ 
 
 3Fe40(S04)5 +4N0 +5H2O. 
 
 Ferric Nitric Water 
 
 subsulphate oxide 
 
 Solution of Ferric Sulphate. 
 6FeS04 +3H2SO4 +2HNO3 = 
 
 Ferrous Sulphuric Nitric 
 
 sulphate acid acid 
 
 3Fe2(S04)3+2NO+4H20. 
 
 Ferric Nitric Water 
 
 sulphate oxide 
 
 Solution of Mercuric Nitrate. 
 HgO + 2HNO3 = Hg(N03)2 + H2O. 
 
 Mercuric Nitric Mercuric Water 
 
 oxide acid nitrate 
 
 Solution of Magnesium Citrate. 
 4MgC03Mg(OH)2+5H3C6H507 = 
 
 Magnesium Citric acid 
 
 carbonate 
 
 5MgHC6H507 +4CO2 +6H2O. 
 
 Magnesium Carbon Water 
 
 acid citrate dioxide 
 
 2KHCO3 +H3C6H507 = K2HC6H507 +2CO2 +2H2O. 
 
 Potassium Citric acid Potassium Carbon Water 
 
 bicarbonate acid citrate dioxide 
 
 (Probably). 
 
172 
 
 WHYS IN PHARMACY. 
 
 Solution of Lead Subacetate. 
 
 Pb(C2H302)2 +PbO = Pb20(C2H302)2: 
 
 Lead Lead Lead sub- 
 
 acetate * oxide acetate 
 
 Solution of Potassium Arsenite. 
 
 AS2O3 + 4KHCO3 = 2K2HASO3 + H2O + 4CO2; 
 
 Arsenous Potassium Potassium Water Carbon 
 
 oxide bicarbonate acid arsenite dioxide 
 
 or, 
 
 AS203 + 2KHC03 + H20 = 
 
 = 2KH2ASO3 + 2CO2; 
 
 Arsenous Potassium Water 
 
 Potassium Carbon 
 
 oxide bicarbonate 
 
 acid arsenite dioxide 
 
 or, 
 
 AS2O3 + 2KHCO3 = 2KASO2 + H2O + 2CO2; 
 
 Potassium Water Carbon 
 
 met-arsenite dioxide 
 
 Arsenous 
 oxide 
 
 Potassium 
 bicarbonate 
 
 and 
 
 2KHCO3 + boiling 
 
 Potassium 
 bicarbonate 
 
 K2CO3 + H2O + CO2. 
 
 Potassium Water Carbon 
 
 carbonate dioxide 
 
 It is not definitely known which of the first three 
 reactions take place. The solution is alkaUne from 
 the potassium carbonate formed. 
 
 Solution of Potassium Citrate. 
 3KHCO3 +H3C6H507 = K3C6H507 + 3H2O +3C02. 
 
 Potassium Citric acid Potassium Water Carbon 
 
 bicarbonate citrate dioxide 
 
EQUATIONS SHOWING CHEMICAL REACTIONS. 173 
 
 Ca(0Cl)2 
 
 Calcium 
 hypochlorite 
 
 Solution of Chlorinated Soda. 
 
 + CaCl2 
 
 Calcium 
 chloride 
 
 + 2Na2C03 = 
 
 Sodium 
 hypochlorite 
 
 Sodium 
 carbonate 
 
 2NaOCl + 2NaCI + 2CaC03. 
 
 Sodium 
 chloride 
 
 Calcium 
 carbonate 
 
 Solution of Zinc Chloride. 
 
 Zn + 2HC1 = ZnCl2 
 
 Zinc Hydro- Zinc 
 
 chloric acid chloride 
 
 Fe + 2HC1 = 
 
 Iron Hydro- 
 
 chloric acid 
 
 3FeCl2 + 3HC1 + HNO3 = 
 
 Ferrous Hydro- Nitric 
 
 chloride chloric acid acid 
 
 FeCl2 
 
 Ferrous 
 chloride 
 
 + H2. 
 
 Hydrogen 
 
 + H2. 
 
 Hydrogen 
 
 3FeCl3 + NO + 2H2O. 
 
 Ferric Nitric Water 
 
 chloride oxide 
 
 2FeCl3 +3ZnC03 +3H20 = 2Fe(OH)3 +3ZnCl2 +3CO2. 
 
 Ferric Zinc Water Ferric Zinc Carbon 
 
 chloride carbonate hydroxide chloride dioxide 
 
 The last three reactions take place if iron is present 
 as an impurity. 
 
 Precipitated Manganese Dioxide. 
 MnS04 + 2NH4OH + H2O2 = 
 
 Manganese 
 sulphate 
 
 Ammonia 
 
 Hydrogen 
 dioxide 
 
 Mn02 + (NH4)2S04 +2H2O. 
 
 Manganese Ammonium Water 
 
 dioxide sulphate 
 
 Mass of Ferrous Carbonate. 
 
 FeS04 + NasCOs = FeC03 + Na2S04. 
 
 Ferrous Sodium Ferrous Sodium 
 
 sulphate carbonate carbonate sulphate 
 
174 
 
 WHYS IN PHARMACY. 
 
 Compound Iron Mixture. 
 FeS04 + K2CO3 = FeCOs + K2SO4. 
 
 Ferrous 
 sulphate 
 
 Potassium 
 carbonate 
 
 Ferrous 
 carbonate 
 
 Potassium 
 sulphate 
 
 Resin in myrrh +Potassium carbonate = 
 
 Resin soap + Carbon dioxide. 
 
 Mixture of Rhubarb and Soda. 
 
 Resin in rhubarb + Sodium bicarbonate = 
 
 Resin soap + Carbon dioxide. 
 
 Oleate of Atropine. 
 
 C17H23NO3 +HCi8H3302 = Ci7H23N03HCi8H3302. 
 
 Atropine Oleic acid Atropine oleate 
 
 Oleate of Mercury. 
 
 HgO + 2HC18H33O2 = Hg(Ci8H3302)2 + H2O. 
 
 Mercuric 
 oxide 
 
 Oleic acid 
 
 Mercuric oleate 
 
 Water 
 
 Pills of Carbonate of Iron. 
 
 FeS04 
 
 Ferrous 
 sulphate 
 
 + K2CO3 
 
 Potassium 
 carbonate 
 
 = FeCOs 
 
 Ferrous 
 carbonate 
 
 + K2SO4. 
 
 Potassium 
 sulphate 
 
 Pills of Iodide of Iron. 
 Fe + I2 = Fel2. 
 
 Iron Iodine Ferrous iodide 
 
 Compound Effervescing Powder. 
 2NaHC03 +H2C4H406 = Na2C4H406 +2CO2 +2H2O. 
 
 Sodium 
 bicarbonate 
 
 Tartaric 
 acid 
 
 Sodium 
 tartrate 
 
 Carbon 
 dioxide 
 
 Water 
 
EQUATIONS SHOWING CHEMICAL REACTIONS. 175 
 
 Spirit of Nitrous Ether. 
 
 2NaN02 + H2SO. 
 
 Sodium 
 nitrite 
 
 Sulphuric 
 acid 
 
 Na2S04 
 
 Sodium 
 sulphate 
 
 + 
 
 2HNO2. 
 
 Nitrous 
 acid 
 
 C2H5OH 
 
 Alcohol 
 
 + 
 
 HNO2 
 
 Nitrous acid 
 
 C2H5NO2 
 
 Ethyl nitrite 
 
 + H2O. 
 
 Water 
 
 Aromatic Spirit of Ammonia. 
 NH4HCO3 • NH4NH2CO2 +NH4OH = 2(NH4)2C03. 
 
 Ammonium bicarbonate Ammonia Ammonium 
 
 and carbamate carbonate 
 
 Iodide of Sulphur. 
 
 12+82 = I2S2. 
 
 Iodine Sulphur Iodide of sulphur 
 
 Washed Sulphur. 
 
 H2SO4 + 2NH4OH = (NH4)2S04 
 Sulphuric Ammonia Ammonium 
 
 acid I sulphate 
 
 + 2H2O. 
 
 Water 
 
 AS2S3 +6NH40H= (NH4)3As03 + (NH4)3AsS3 +3H0. 
 
 Arsenous Ammonia Ammonium Ammonium Water 
 
 sulphide arsenite sulphar- 
 
 senite 
 
 Precipitated Sulphur. 
 
 CaO 
 
 Linie 
 
 + 
 
 3Ca(OH)2 + 12s 
 
 Calcium Sulphur 
 
 hydroxide 
 
 H2O = Ca(0H)2. 
 
 Water Calcium hydroxide 
 
 = 2CaS5 + CaS203 + 3H2O. 
 
 Calcium Calcium Water 
 
 penta- thiosui- 
 
 sulphide phate 
 
176 
 
 WHYS IN PHARMACY. 
 
 2As2S3+6Ca(OH)2 = Ca3(As03)2 + Ca3(AsS3)2 + 6H20. 
 
 Arsenous Calcium Calcium Calcium Water 
 
 sulphide hydroxide arsenite sulph- 
 
 arsenite 
 
 CaS5 + 2HC1 = 
 
 Calcium 
 
 penta- 
 
 sulphide 
 
 Hydro- 
 chloric acid 
 
 CaCl2 
 
 Calcium 
 chloride 
 
 + 4S 
 
 Sulphur 
 
 + 
 
 H2S. 
 
 Hydrogen 
 sulphide 
 
 Glycerin Suppositories. 
 
 Na2C03 +2HCi8H3502 = 2NaCi8H3502 +CO2 +H2O. 
 
 Sodium Stearic acid Sodium Carbon Water 
 
 carbonate stearate dioxide 
 
 Syrup Calcium Lactophosphate. 
 
 CaCOg +2HC3H5O3 = Ca(C3H503)2 +CO2 +H2O. 
 
 Calcium 
 carbonate 
 
 Lactic acid 
 
 Calcium 
 lactate 
 
 Carbon 
 dioxide 
 
 Water 
 
 Ca(C3H503)2 + H3PO4 = CaHP04 + 2HC3H5O3. 
 
 Calcium Phosphoric Calcium Lactic acid 
 
 laetate acid acid phosphate 
 
 Syrup of Lime. 
 
 CaO+H20=-Ca(HO)2. 
 
 Lime Water Calcium 
 hydroxide 
 
 Syrup Iodide of Iron. 
 
 Fe + I2 = Fel2. 
 
 Iron Iodine Ferrous 
 iodide 
 
EQUATIONS SHOWING CHEMICAL REACTIONS. 177 
 
 Tincture of Ferric Chloride. 
 C2H5OH + HCl = C2H5CI + H2O, (probably). 
 
 Alcohol Hydro- Ethyl Water 
 
 chloric acid chloride 
 
 Ointment of Mercuric Nitrate. 
 3Hg + 8HNO3 = 3Hg(N03)2 + 2N0 + 4H2O. 
 
 Mercury Nitric Mercuric Nitric Water 
 
 acid nitrate oxide 
 
 Lard + Nitric a cid = Elaidin+ Nitric oxide. 
 
INDEX. 
 
 PAGE 
 
 Acacia 13, 142 
 
 mucilage of 41, 142, 155 
 
 syrup of 64 
 
 Acid, acetic 83 
 
 arsenous 94, 1 57 
 
 solution of 29, 169 
 
 benzoic 84, 148, 157 
 
 boric 84 
 
 carbolic 121, 142, 143, 146, 155, 159 
 
 chromic 96 
 
 citric 84, 154 
 
 syrup of 64 
 
 hydriodic acid 85, 165 
 
 hydrochloric 85 
 
 hydrocyanic 86, 149, 165 
 
 hypophosphorous 86 
 
 lactic 87 
 
 meconic 136 
 
 nitric 87 
 
 nitrohydrochloric 87, 165 
 
 phosphoric 88, 154, 155 
 
 salicylic 89, 148 
 
 elixir of 9 
 
 ointment of 80 
 
 179 
 
ISO INDEX, 
 
 PAGE 
 
 Acid, sulphuric 89 
 
 aromatic 90, 166 
 
 sulphurous 91, 166 
 
 tannic 91, 147 
 
 ointment of 79 
 
 suppositories of 63 
 
 Acids 83 
 
 Aconite, assay of 136 
 
 Aconitine 128, 136 
 
 Albumin 159 
 
 Alcohol 117, 153, 159 
 
 Alkaloids 126 
 
 definition of 126 
 
 estimation of 127 
 
 preservation of 126 
 
 Aloes 117 
 
 extract of 23 
 
 Alum 92 
 
 Aluminum hydroxide 92, 166 
 
 Ammonia, liniment of 27, 169 
 
 spirit of 60 
 
 aromatic 60, 175 
 
 water of 3, 153 
 
 Ammonium acetate 147 
 
 solution of 29, 70 
 
 benzoate 93 
 
 carbonate 93, 143, 145 
 
 iodide 93 
 
 Antidotes to poisons 158 
 
 Antimony and potassium tartrate 93, 151 
 
 Antipyrine 143, 146, 147, 151 
 
 Apomorphine hydrochloride 136 
 
 Arsenic trioxide 94, 157 
 
 Atropine 128 
 
 oleate of 174 
 
 Balances 1 60 
 
 Bay, oil of 49 
 
INDEX. 181 
 
 PAGE 
 
 Bay, spirit of 61 
 
 Bay rum 61 
 
 Beeswax 119 
 
 Belladonna 117 
 
 extract of 23 
 
 fluid extract of 20 
 
 Bicarbonate of potassium 109 
 
 Bicarbonates of alkalies 140, 141 
 
 Bismuth and ammonium citrate 95 
 
 elixir of 10 
 
 citrate 94, 166 
 
 subnitrate 95^ 152 
 
 Bitter-almond oil 47 
 
 water 4 
 
 Blue mass 39 
 
 ointment 81 
 
 Borax 148, 149, 151 
 
 Bumping 161 
 
 Caffeine citrate 118 
 
 effervescing 58 
 
 Calcium carbonate 95 
 
 iodide, syrup of 69 
 
 lactophosphate, syrup of 65 176 
 
 oxide 95 
 
 salts 95 
 
 Calomel 103, 156, 157 
 
 Camphor 118, 143 
 
 water 4 
 
 Cannabis indica 118 
 
 Cantharides cerate g 
 
 collodion 7 
 
 Carbonates, alkali I44 1 55 
 
 Cardamom 12o 
 
 Carmin in elixirs 9 
 
 solution of 37 
 
 Cascara sagrada 123 
 
 aromatic fluid extract of 21 
 
182 INDEX. 
 
 PAGE 
 
 Cerate 6 
 
 cantharides 6 
 
 lead subacetate 6 
 
 resin 6 
 
 Cerates 5 
 
 Chalk mixture 40 
 
 prepared 96 
 
 Charcoal, animal 118, 159, 167 
 
 Chemicals 83 
 
 Chloral hydrate 141, 146, 152, 153, 158 
 
 Chlorinated soda, solution of 35, 36, 173 
 
 Chlorine, compound solution of 31, 170 
 
 water of 4 
 
 Chloroform 119 
 
 mulsion of 14 
 
 niment of 28 
 
 water of 5 
 
 Chondrus 119 
 
 mucilage of 42 
 
 Chromium trioxide 96 
 
 Cinchona 119 
 
 assay of 128 
 
 detannated tincture of 75 
 
 elixir of 10 
 
 infusion of 27 
 
 Citrine ointment 81, 177 
 
 Clarification 163 
 
 Coating pills 52 
 
 Cocaine 149, 158 
 
 Cochineal • • 119 
 
 Codeine 149 
 
 Colchicum, assay of 136 
 
 extract of 24 
 
 Collodion 7 
 
 cantharides 7 
 
 flexible 7 
 
 Condensers 164 
 
 Conium, assay of 136 
 
INDEX. 183 
 
 PAGE 
 
 Conium, fluid extract of 20 
 
 Corrosive sublimate 102, 151 
 
 solution of 141 
 
 tablets of 141 
 
 Cotton 121 
 
 Court-plaster 12 
 
 Creosote 120 
 
 Crystallization 164 
 
 Cubebs 120 
 
 oleoresin of 43 
 
 Decoctions 8 
 
 Diachylon ointment 80 
 
 Dobell's solution 38 
 
 Donovan's solution 30 
 
 Dover's powder 56 
 
 Drops 160 
 
 Drugs, assay of 126 
 
 organic 117 
 
 powdered 117 
 
 Elixir of ammonium valerate 9 
 
 anise 10 
 
 aromatic 8 
 
 bismuth 10 
 
 buchu t 10 
 
 cinchona 10 
 
 digestive, compound 10 
 
 gentian 11 
 
 iron, quinine, and strychnine 9 
 
 pepsin and bismuth 11 
 
 salicylic acid 9 
 
 soluble phosphate of iron 9 
 
 yerba santa aromatic. 10 
 
 Elixirs 8 
 
 carmin in 9 
 
 Emetics 1 58 
 
 Emulsion of chloroform 14 
 
 cod-liver oil 14 
 
184 INDEX. 
 
 PAGB 
 
 Emulsions 12 
 
 Equations. 165 
 
 Ergot 120 
 
 extract of 24 
 
 fluid extract of 20 
 
 Ether 117 
 
 Eucalyptus 120 
 
 oil of 48 
 
 Euphorin 143 
 
 Evaporation 163 
 
 Exalgin 143 
 
 Excipients, pill 51 
 
 Extract of aloes 23 
 
 belladonna 23 
 
 colchicum 24 
 
 colocynth 24 
 
 compound 24 
 
 ergot. 24 
 
 gentian 24 
 
 glycyrrhiza 24 
 
 hyoscyamus 23 
 
 logwood 25 
 
 nux vomica 25 
 
 quassia 25 
 
 physostigma 23 
 
 Extracts 22 
 
 from fluid extracts 23 
 
 glycerin in 23 
 
 licorice-root in 23 
 
 variation in 22 
 
 Filtration 134,161,162 
 
 Flame, non-luminous 1 64 
 
 Fluid extract of belladonna 20 
 
 cascara, aromatic 21 
 
 conium 20 
 
 ergot 20 
 
 glycyrrhiza 20 
 
 lupulin 20 
 
INDEX. 185 
 
 PAGE 
 
 Fluid extract of mix vomica 21 
 
 sangLiinaria 21 
 
 senega 21 
 
 taraxacum 22 
 
 triticum 22 
 
 wild cherry 21 
 
 Fluid extracts 14 
 
 by repercolation. 19 
 
 evaporation in making 17 
 
 glycerin in 19 
 
 precipitation of 18 
 
 preservation of 19 
 
 Fowler's solution 34, 154, 172 
 
 Funnels 161 
 
 Gentian 120 
 
 elixir of 11 
 
 extract of 24 
 
 Ginger 125 
 
 solution of 38 
 
 Ginseng 121 
 
 Glycerin 121, 151, 156 
 
 in extracts 23 
 
 in fluid extracts 19 
 
 suppositories of 63, 176 
 
 Glycerite of boroglycerin 26, 168 
 
 starch 25 
 
 Glycyrrhiza 121 
 
 compound powder of 56 
 
 extract of 24 
 
 fluid extract of 20 
 
 in extracts 23 
 
 Glycyrrhizin 121 
 
 Gold and sodium chloride 94, 146 
 
 Granular effervescing powders 57 
 
 Honey 1 45 
 
 Hydrastine 137 
 
 Hydrogen dioxide water 5 
 
186 INDEX. 
 
 PAGE 
 
 Hyoscyamine 182 
 
 Hyoscyamus, extract of 23 
 
 Hypodermic solutions » 141 
 
 Ichthyol 146 
 
 suppositories of 63 
 
 Infusion of cinchona 27 
 
 digitalis 27 
 
 wild cherry 27, 169 
 
 Infusions 26 
 
 Inorganic compounds 92 
 
 Iodine 153, 154 
 
 compound solution of 33 
 
 ointment of 81 
 
 pills of 1 53 
 
 tincture of 73 
 
 Churchill's 76 
 
 decolorized 76 
 
 Iodoform 158 
 
 ointment of 81 
 
 suppositories of 63 
 
 Irish moss 119 
 
 mucilage of 42 
 
 Iron and ammonium citrate 98, 1 43 
 
 tartrate 98 
 
 quinine citrate 98 
 
 strychnine citrate 98 
 
 carbonate, mass of 38, 173 
 
 pills of 53, 174 
 
 saccharated 96, 167 
 
 chloride 97 
 
 solution of 31 , 1 70 
 
 tincture of 72, 155, 177 
 
 ethereal 75 
 
 citrate 97 
 
 solution of 97 
 
 dialyzed, solution of 32 
 
 hydroxide 99, 157, 167 
 
INDEX. 187 
 
 PAGE 
 
 Iron hypophosphite 98 
 
 solution of 37 
 
 syrup of 70 
 
 iodide ' 99 
 
 pills of 53, 174 
 
 saccharated 99 
 
 solution of 37, 155 
 
 syrup of 65, 1 76 
 
 mixture, compound 40, 174 
 
 phosphate, soluble 100, 155 
 
 pyrophosphate, soluble 100 
 
 quinine and strychnine, elixir of 9 
 
 syrup of 66 
 
 reduced 101 
 
 salts of 97 
 
 scale 153 
 
 subsulphate, solution of 32, 171 
 
 sulphate 100, 143 
 
 dried 100 
 
 granulated 101 
 
 solution of 171 
 
 Kino 121 
 
 tincture of 73 
 
 Labarraque's solution 35, 36, 173 
 
 Lard 79 
 
 oil 45 
 
 Laudanum 74, 134, 145 
 
 Lead acetate 108, 143 
 
 iodide 108 
 
 nitrate 108 
 
 oleate 42 
 
 oxide 108 
 
 plaster 12, 167 
 
 salts 108 
 
 subacetate, cerate of 6 
 
 solution of 34, 172 
 
188 INDEX. 
 
 PAGE 
 
 Lead water 145 
 
 Licorice 121 
 
 compound powder of 56 
 
 extract of 24 
 
 fluid extract of 20 
 
 in extracts 23 
 
 Lime 95 
 
 chlorinated 95 
 
 solution of 30, 1 70 
 
 sulphurated 96, 167 
 
 syrup of 65, 1 76 
 
 Liniment of ammonia 27, 169 
 
 chloroform 28 
 
 soap 28 
 
 Liniments 27 
 
 Lozenges 77 
 
 Lycopodium 121 
 
 Magnesium carbonate 107 
 
 citrate, effervescing 59 
 
 solution of 33, 171 
 
 oxide 107 
 
 Male fern 117 
 
 oleoresin of 43, 157 
 
 Mandrake, resin of 59 
 
 Mass of copaiba 39 
 
 iron carbonate 38, 173 
 
 mercury 39 
 
 Mayer's reagent 144 
 
 Menthol 143 
 
 Mercuric chloride 102, 151 
 
 solution of 141 
 
 tablets of 141 
 
 iodide 104, 143, 168 
 
 nitrate, solution of 33, 172 
 
 ointment of 80, 1 77 
 
 oxide 104, 169 
 
 ointment of 81 
 
INDEX. . 189 
 
 PAGE 
 
 Mercuric subsulphate 105 
 
 Mercurous chloride 103, 156, 157 
 
 iodide 103, 143, 168 
 
 Mercury, ammoniated 106, 169 
 
 in thermometers 161 
 
 mass of 39 
 
 ointment of 80 
 
 oleate of 42, 174 
 
 plaster of 12 
 
 salts of 102 
 
 with chalk 106 
 
 Miscellaneous 160 
 
 Mixture, chalk 40 
 
 chloral and potassium bromide 40 
 
 iron, compound 40, 174 
 
 rhubarb and soda 1 74 
 
 Morphine 135, 158 
 
 Monsel's solution 32, 171 
 
 Mucilage of acacia 41, 142, 155 
 
 Irish moss 42 
 
 tragacanth 41 
 
 Mustard 124 
 
 oil of 50 
 
 paper of 6 
 
 Naphtol 143 
 
 Narcotine 135 
 
 Nitroglycerin, spirit of 61 
 
 Nitrous ether, spirit of 59 
 
 Nutmegs 121 
 
 Nux vomica, assay of 130 
 
 extract of 25 
 
 fluid extract of 21 
 
 tincture of 74 
 
 Oil of almond, expressed 45 
 
 bay 49 
 
 bitter almond 47 
 
190 INDEX. 
 
 PAGE 
 
 Oil of cajuput 48 
 
 cassia 48 
 
 castor 46, 157 
 
 cloves. 48 
 
 cod liver 45 
 
 emulsion of 14 
 
 cottonseed 45 
 
 eucalyptus 48 
 
 juniper 48 
 
 lard 45 
 
 lemon 48 
 
 linseed 45 
 
 mustard 50 
 
 olive. 46, 157 
 
 orange 49 
 
 patchouly 49 
 
 peppermint 49 
 
 phosphorated 46 
 
 pimenta 49 
 
 rose 49 
 
 rosemary 48 
 
 sandalwood 49 
 
 theobroma 62, 152 
 
 turpentine 50, 154 
 
 vetivert 50 
 
 Oils, fixed 44 
 
 volatile 46 
 
 Ointment, blue 81 
 
 citrine 80, 177 
 
 diachylon 80 
 
 iodine 81 
 
 iodoform 81 
 
 mercurial 80 
 
 mercuric nitrate 81, 177 
 
 oxide of mercury 81 
 
 potassium iodide 82 
 
 rose-water 80 
 
 salicylic acid 80 
 
INDEX. 191 
 
 PAGE 
 
 Ointment, tannic acid 79 
 
 zinc oxide 82 
 
 Ointments 77 
 
 Oleate of atropine 174 
 
 lead 42 
 
 mercury 42, 174 
 
 Oleoresin of capsicum 43 
 
 cubeb 43 
 
 lupulin 43 
 
 male fern 43 
 
 Oleoresins 43 
 
 Opium, assay of 132 
 
 tincture of 74, 134, 145 
 
 deodorized 74 
 
 Ox-gall 120 
 
 Pancreatin, solution of 37 
 
 Paper, mustard 6 
 
 Pearson's solution ". 38 
 
 Pepsin, elixir of 11 
 
 solution of 37 
 
 Percolation 14 
 
 Percolators 15 
 
 Petrolatum 78 
 
 Phenacetin 143 
 
 Phenol 121, 142, 143, 146, 155, 159 
 
 Phosphorus, pills of 54 
 
 spirit of 62 
 
 Physostigma , 123 
 
 assay of 137 
 
 extract of 23 
 
 Physostigmine 137 
 
 Pills 50 
 
 aloes and iron 53 
 
 carbonate of iron 53, 1 74 
 
 coating 52 
 
 excipients 51 
 
 iodine 53 
 
192 INDEX. 
 
 PAGE 
 
 Pills, iron bromide 153 
 
 iodide 53, 174 
 
 phosphorus 54 
 
 Pilocarpine 137 
 
 Pilocarpus 123 
 
 Plaster, court 12 
 
 lead 12, 167 
 
 mercurial 12 
 
 Plasters 11 
 
 Podophyllum 123 
 
 resin of 59 
 
 Poisons, antidotes to 158 
 
 Potassa, sulphurated 109 
 
 with lime 109 
 
 Potassium acetate ^109, 143, 147 
 
 and sodium tartrate Ill 
 
 arsenite, solution of 34, 154, 172 
 
 bicarbonate 109 
 
 bromide 109 
 
 carbonate 110, 143 
 
 chlorate 110, 144, 145, 155 
 
 citrate Ill, 147 
 
 solution of 35, 172 
 
 cyanide Ill 
 
 hydroxide Ill 
 
 solution of 35 
 
 hypophosphite 112, 143, 156 
 
 iodide 112, 143, 146, 155, 156 
 
 ointment of 82 
 
 solution of 141 
 
 mercuric iodide 144 
 
 permanganate 113, 144 
 
 salts of 109 
 
 Powder, compound chalk 55 
 
 compound effervescing 56, 174 
 
 Dover's 56 
 
 effervescing caffeine citrate 58 
 
 glycyrrhiza, compound 56 
 
INDEX. 193 
 
 PAGE 
 
 Powder, ipecac and opium 5q 
 
 lithium citrate, effervescing 58 
 
 magnesium citrate, effervescing 59 
 
 rhubarb, compound 57 
 
 Seidlitz 56, 174 
 
 Powders 54 
 
 dispensing 142 
 
 granular effervescing 57 
 
 solids not to be dispensed in form of 142 
 
 Precipitation 164 
 
 Prescriptions 138 
 
 doses of 139 
 
 Pyroxylin I23 
 
 Quinine 129, 139, 149 
 
 Repercolation I9 
 
 Resin cerate g 
 
 ot mandrake 59 
 
 Resins 59 
 
 Resorcin I43 
 
 Rochelle salt HI 
 
 Rose flowers 124 
 
 oil of 49 
 
 Saccharin, solution of 33 
 
 Salol. 143 
 
 Sanguinaria, fluid extract of 21 
 
 syrup of 70 
 
 tincture of 75 
 
 Santonin. 124 
 
 Seidlitz powder 56 1 74 
 
 Silver nitrate 94, 148, 166 
 
 oxide 94 
 
 salts of 143, 144 
 
 Soap 156 
 
 liniment 28 
 
 Sodium borate 148, 149, 151 
 
194 INDEX. . 
 
 PAGE 
 
 Sodium bromide 143, 151 
 
 carbonate 143 
 
 dried 113 
 
 chloride 114 
 
 hydroxide 114 
 
 hypophosphite 143 
 
 iodide 114, 143 
 
 phosphate 143, 148 
 
 salicylate 114, 151 
 
 sulphate 143 
 
 sulphocarbolate 114 
 
 Solution of ammonium acetate 29, 170 
 
 arsenous acid 29, 169 
 
 arsenous and mercuric iodides 30 
 
 carmin 37 
 
 chlorinated soda 35, 36, 173 
 
 chlorine compound 31, 170 
 
 DobelPs 38 
 
 Fowler's 34, 154, 172 
 
 ginger 38 
 
 gutta percha 37 
 
 iodine compound 33 
 
 iron and ammonium acetate 32, 170 
 
 chloride 31, 170 
 
 citrate 97 
 
 dialyzed 32 
 
 hypophosphite 37 
 
 iodide 37,155 
 
 subsulphate 32, 171 
 
 sulphate 171 
 
 Labarraque's 35, 36, 173 
 
 lead subacetate 34, 1 72 
 
 dilute 145 
 
 lime 30,170 
 
 magnesium citrate, effervescing 33, 171 
 
 mercuric chloride 141 
 
 nitrate 33, 171 
 
 Monsel's 32, 171 
 
INDEX. 195 
 
 PAGE 
 
 Solution of pancreatin 37 
 
 Pearson's 38 
 
 pepsin 37 
 
 potassium arsenite 34, 154, 172 
 
 citrate 35,172 
 
 hydroxide 35 
 
 saccharin 38 
 
 sodium borate, compound 38 
 
 zinc chloride 36, 1 73 
 
 Solutions 29 
 
 at the prescription counter 140 
 
 hypodermic 141 
 
 of substances in water 1 62 
 
 stock 141 
 
 Spermaceti. 119 
 
 Spirit of ammonia 60 
 
 aromatic 60, 175 
 
 lemon 61 
 
 myrcia 61 
 
 nitroglycerin 61 
 
 nitrous ether 59, 146, 175 
 
 peppermint 61 
 
 phosphorus 62 
 
 Spirits 59 
 
 Starch, glycerite of 25 
 
 Strychnine 130, 132 
 
 Sulphur, iodide of 175 
 
 precipitated 115, 175 
 
 sublimed 115, 175 
 
 washed 115, 175 
 
 Suppositories 62 
 
 chloral hydrate 152 
 
 glycerin 63, 176 
 
 ichthyol 63 
 
 iodoform 63 
 
 tannic acid 63 
 
 Sweet spirit of nitre 59, 146, 175 
 
 Syrup of acacia 64 
 
196 INDEX. 
 
 PAGE 
 
 Syrup of althsea , 64 
 
 asarum compound 69 
 
 calcium iodide 69 
 
 lactophosphate 65, 176 
 
 with iron 69 
 
 citric acid 64 
 
 hypophosphites 67 
 
 calcium and sodium 69 
 
 compound 67 
 
 with iron 67 
 
 ipecac 67, 145 
 
 iron citro-iodide 70 
 
 hypophosphite 70 
 
 iodide 65, 155, 176 
 
 quinine and strychnine phosphates 66 
 
 lime 65, 176 
 
 orange 64 
 
 raspberry 68 
 
 rhubarb 68 
 
 sanguinaria 70 
 
 sarsaparilla, compound 68 
 
 squills 68, 145 
 
 compound 69 
 
 tar 67 
 
 wild cherry 68 
 
 yerba santa, aromatic 70 
 
 Syrups 63 
 
 Tablet triturates 77 
 
 Talc, purified 115 
 
 Tartar emetic 93, 151 
 
 Temperature, 161, 162 
 
 Thermometers 161 
 
 Thymol 143 
 
 Tincture of aconite, Fleming's 75 
 
 arnica 71 
 
 cinchona, detannated 75 
 
 fresh herbs 71 
 
INDEX. 197 
 
 PAGE 
 
 Tincture of gambir, compovmd 72 
 
 guaiac, compound 76 
 
 iodine 73, 149 
 
 Churchill's 76 
 
 decolorized 76 
 
 ipecac and opium. , 73 
 
 iron chloride 72 177 
 
 ethereal 75 
 
 citro-chloride 76 
 
 kino 73 
 
 lactucarium 74 
 
 musk 74 
 
 myrrh I45 
 
 nux vomica 74 
 
 opium 74, 134, 145 
 
 deodorized 74 
 
 orange 71 
 
 rhubarb, aqueous 74 
 
 sanguinaria 75 
 
 soap bark 74 
 
 strophanthus 75 
 
 vanilla 75 
 
 Tinctures 70 
 
 Tragacanth 124, 142 
 
 mucilage of 41 
 
 Trituration of solids 143 
 
 Troches 77 
 
 Turpeth mineral 105 
 
 Urine 157 
 
 Veratrine 137 
 
 Water of ammonia 3^ I53 
 
 bitter almond 4 
 
 camphor 4 
 
 chlorine 4 
 
 chloroform 5 
 
198 INDEX. 
 
 PAGB 
 
 Water, distilled 3 
 
 hardness of 3 
 
 hydrogen dioxide 5 
 
 orange 4 
 
 Waters, methods of making 1 
 
 preservation of " 2 
 
 Whiskey 61 
 
 White precipitate 106 
 
 Wild cherry, fluid extract of 21 
 
 infusion of 27, 169 
 
 syrup of 68 
 
 Wines 82 
 
 Wool-fat, hydrous 78 
 
 Yerba santa, aromatic syrup of 70 
 
 elixir of 10 
 
 Zinc acetate "> • • • 143 
 
 chloride 115 
 
 solution of 36, 173 
 
 oxide, ointment of 82 
 
 sulphate 116, 148 
 
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