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Critical and Explanatory CommentsON THE

NEW PHARMACOPŒIA,INDICATING THE

EXTENT AND CHARACTER OF THE CHANGES MADE,AND THE RELATIVE VALUE OF THE NEW

AND OLD PROCESSES & PREPARATIONS.

No. III.

Ix the British Pharmacopoeia, the aconite plant is only usedfor making the extract. The root is the part chiefly employed.From this is prepared the tincture, which is only one-thirdthe strength of the London Pharmacopoeia of 1851, and aboutone-sixth of that proposed by Dr. Fleming. For external use

a much stronger tincture is directed-the linimentum aconiti,which appears to be a very efficient preparation. A similar

preparation is made from belladonna-root. This strong alco-holic solution of the root was proposed some years ago by Mr.Squire, and appears to have suggested the liniments of thisclass. It is more cleanly to use than the nasty messes thatwere made by mixing the extract with water or other tinctures,and contains, with very little foreign matter, the active portionof the belladonna. One fluid ounce of these liniments repre-sents one ounce by weight of the dried root. The Pharma-

copeeia contains a process for preparing aconitia; and this isa case in which the Pharmacopoeia may legitimately givedirections for preparing a chemical substance. The aconitineused in commerce is very unreliable; that which is obtainedfrom Germany and other sources being almost worthless.This alkaloid is so useful in certain cases of neuralgia that itis of great importance to get the true active principle; and theprocess proposed by the Pharmacopoeia will yield a product ofgreat medicinal activity. In the Materia Medica it is describedas a white amorphous powder ; but this will hardly be accom-plished without the use of animal charcoal, which is not men-tioned in the process given.The Materia Medica portion appears to have been the work

of a different hand from that which composed the second por-tion (the Processes) of the book; and we are sometimes in adifficulty in reviewing both parts together. The mode of

arrangement is very arbitrary. Thus setheris nitrosi spiritusof the Materia Medica is spiritns eatheris nitrosi of the secondpart; chlori liquor is liquor chlori ; and as both parts arearranged alphabetically, it leads to some confusion. We shall,however, follow the order of the second part, with which weare most concerned, so that ætheris nitrosi spiritus will be con-sidered with the spirits.

Ammoniæ benzoas is a salt which does not occur in any pre-vious Pharmacopoeia, and it is very little used. It is directedto be made by dissolving benzoic acid in liquor ammoniæ andevaporating till crystals form. Nothing is said about howthese crystals are to be dried. If heat be employed, they willcertainly not answer to the description given in the MateriaMedica, where they are described as soluble in water. Ben-zoate of ammonia very readily parts with half its ammonia,and is converted into an acid salt very insoluble in water; andif the mother liquors are evaporated, an excess of ammoniashould be added before crystallization, or nothing but the acidsalt will be obtained.

Ammoniæ phosphas is another novelty also not much in use.This salt is likewise very prone to part with a portion of itsammonia if heat is employed for drying the crystals (the Phar-maeopceia directs drying on a porous brick), but in this casethe acid salt is more soluble than the neutral one.Antimonii oxidum is made by the plan adopted by the Edin-

burgh and Dublin Pharmacopoeias. Its chief use is in making

the pulvis antimonialis and antimonium tartarizatum. Whe-ther the former, as prepared in the new Pharmacopoeia, will bea better substitute for James’s powder than previous compoundsof this nature remains to be seen. We think it rather doubtful.In preparing the latter in any quantity, it must be rememberedthat the recovery of the product by the evaporation of themother liquors will be stopped at a certain point in consequenceof a considerable portion of it being converted into an uncrys-tallizable modification.

Aqua camphorae is the new name for mistura camphorse, andis certainly a more appropriate one, as it is simply the solutionof a solid volatile oil in water. The other waters are all directedto be made by distillation from the drugs, and far better pre-parations are obtained in this way than when the oils dissolvedin spirit are added to water with agitation. Exception is madein the case of the aquæ menthæ piperitæ and viridis, which areto be distilled from a mixture of the oil and water; but mereagitation with the oil and filtration yields in these cases anequally good result.

If aconitia is a proper subject for a pharmacopcela.1 processargenti nitras is decidedly one which ought to have been leftalone, as this chemical is found in commerce in a state of greatpurity. Some notion of the advantage which the pharmaceutistwould derive from making his own nitrate of silver may be ob-tained from the fact that only two firms in Great Britain areable to make any profit at all out of the manufacture. Thesefirms are only enabled to do it because they are also refiners ofgold and silver, and they supply the nitrate at a price, and ina state’ of purity, which set competition at defiance. The

Pharmacopoeia directs refined silver which contains no trace ofcopper to be employed ; that is to say, silver which must havebeen already in solution, and which is now to be reduced tothe metallic state, in order that the follower of the Fharma.copoeia may once more dissolve it.

Argenti oxidum is directed to be made by precipitating asolution of nitrate of silver by a solution of lime, but it is notquite clear why the liquor sodse of the Pharmacopoeia wouldnot answer the same purpose. On account of the slight soln-bility of lime in water, the preparation becomes unnecessarilybulky.The process for the preparation of atropine will be found to

answer well in practice, though this article can be obtained frommanufacturing chemists of excellent quality. The sulphuric-acid solution of the crude atropine is nearly neutralized withcarbonate of potash, by which a matter that interferes withthe crystallization of the alkaloid is separated. After filtration,the atropine is precipitated by an excess of carbonate of potash,and purified from alcohol by solution in chloroform and crystal-lization. Caustic alkali cannot be employed to precipitate thisalkaloid, as it would be entirely decomposed by such treatment.The London Pharmacopoeia contained the sulphate of atropine,but this is unaccountably omitted in the present work. The

sulphate is far more useful than the pure alkaloid, being verysoluble in water, while atropine is not.

Arnica, bebeeriæ sulphas, and bela, have been introduced forthe first time into an English Pharmacopoeia. None of them arevery extensively used.The nitrate of bismuth appears under the name which it bore

in the Edinburgh Pharmacopœia-Bismuthum album. WhyBismuthum album ? The basic nitrate is by no means the onlywhite compound of bismuth. This preparation consists of oxideof bismuth, combined with slightly variable proportions of nitricacid. Its composition will differ somewhat according to themode of preparation and the extent to which it is washed. Theterm employed by the London Pharmacopœia-Bismuthi nitras- indicates this without being committed to its exact composi-tion. It means simply a nitrate of bismuth. Bismuthum albummeans nothing at all. The directions given for its preparationare very wasteful. This is another instance of a process devisedby an amateur. Bismuth is dissolved in nitric acid, and thesolution is poured into a large quantity of distilled water, andthe precipitate which forms is washed and dried. Under thesecircumstances a considerable quantity of bismuth remains insolution, and as the Pharmacopoeia gives no directions for re-covering it, we presume it is to be thrown away. An increasedproduct may be obtained by partially neutralizing the freenitric acid of this dilute solution by an alkali. If the nitrate of

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bismuth is precipitated with cold water, the precipitate will be that the extract made from the soft parts, excluding the leaves,very bulky, and difficult to wash and dry ; if, on the contrary, was positively more active as a dilating agent than that pre-hot water is employed, the precipitate will be dense, and much pa,red from the leaves alone. With regard to the preservationmore manageable. The "Bismuthum album" prepared accord- of the extract, it was found that that made from the leavesing to the British Pharmacopoeia will be very likely to contain became mouldy in three weeks, while the other kept perfectlyarsenic ; but, though this is so constant an impurity in this pre- well. A third experiment proved that an extract made fromparation, the Pharmacopoeia omits to notice it altogether, and the whole of the soft parts, including the leaves, was in every.gives no test for its detection. Nitrate of bismuth is usually respect satisfactory, and would keep perfectly. So far themade as follows :-Metallic bismuth is dissolved in nitric acid, Pharmacopoeia has adopted the variation from its precepts,and the solution is allowed to cool. Under these circumstances which has been found practically useful. The new process forthe acid nitrate crystallizes in large crystals of great beauty. preparing the extract has been founded on theoretical consi.The mother liquors, which contain the arsenic and other impu- derations, the value of which can only be determined by prac-Tities, are worked up in future operations. The crystallized tice. The expressed juice is first heated to 130°, by which thenitrate is now treated with hot water, which abstracts a por- chlorophyle is separated, and the temperature of the filtered juicetion of the nitric acid, and leaves the basic nitrate in the form is then raised to 200°, which determines the coagulation of theof a dense crystalline powder, very pure and beautifully white, albumen present. The clear filtrate is now to be evaporatedThe water which runs off may be used for making carbonate of at the full temperature of the water-bath to a syrupy consist-bismuth, which is rather extensively prescribed, but is not re- ence, when the chlorophyle previously separated is added, andcognised in the new Pharmacopoeia,, the extract is finished at a heat not exceeding 140°. In thisThe Cataplasmata are peculiarly London formula, and they way the chlorophyle (which is discoloured at high temperatures)

are continued without change by the British Pharmacopoeia. is removed from the influence of heat during the evaporation ofThe class of compounds called Cerata has disappeared, though the bulk of the juice, and a green extract is obtained. Themany of these may be found under another name amongst the efficiency of the removal of the albumen is more doubtful. ItUnguenta. This is a judicious simplification, as there is no is bv no means certain that the nitrogenous matter coagulated’reason for separating those ointments which contain wax from at 200° is the cause of the fermentation which is sometimes set- those that do not. up in extracts of this nature. We are not aware that it has

Camphora is described as " a concrete volatile oil, obtained been the practice of the manufacturers to separate this albumen,-from the wood by sublimation, and resublimed in bell-sha,ped and so far as our experience goes the keeping powers of the ex-masses ; imported from China." This passage would lead the tract are not sensibly improved. Further investigation isTeader to suppose that camphor is imported from China resub- wanted on this point, but we believe a better extract would befimated in bell-shaped masses, which is not the case. The obtained if no part of the juice was exposed to a higher tem-,crude camphor alone comes from China, mixed with many im- perature than 140° ; though, of course, the operation would bepurities. The resublimation takes place in England ; and as much prolonged. Those who wish to make their own greenthe Pharmacopoeia gives processes for almost everything, it extracts and to experiment on this matter should provide them.seems inconsistent to omit one for purifying the crude drug. selves with a suitable mill for crushing the plant. It is a hope-On what principle are the processes of the British Pharma- less task to bruise 1121bs. of green herb in a stone mortar, ascopœia selected ? suggested by the Pharmacopoeia; one half would be totally

Probably no two manufacturers prepare chloroform in spoiled before the other half was sufficiently comminuted.exactly the same way, and it is difficult to say a-tsolutely The fluid extracts which appear in the British Pharmacopoeiawhat are the best proportions of the materials employed ; but are a most satisfactory class of preparations, and we are con-the process of the British Pharmacopoeia will yield a product of vinced that they will come into very extensive use. Under,excellent quality, and may be recommended for general use. this head we may mention extractum cinchonæ liquidum, which’Collodion is introduced into the Pharmacopoeia, with direc- represents the infusum cinchonse spissatum of the London Phar-tions for its preparation. The quality of the product will macopœia. of 1851. The extensive use of this preparation shows,depend much upon the temperature of the acids employed in how popular these fluid extracts are likely to be. Extractumthe manufacture of the pyroxylin. The Pharmacopoeia gives ergotae liquidum contains a curious commentary on the oldno directions on this point, but lets the temperature take its tinctura ergotm Eetheria. According to the British Pharma-chance. Collodion is required of two kinds-contractile and copoeia the ergot is first treated with ether, and all that thenon-contractile. The Pharmacopoeia directions may lead to ether removes is to be rejected as worthless. We believe thateither, though very little spirit should be employed for the the Pharmacopœia is quite right in this matter ; the ether, in-contractile variety. fact, removes nothing but oil. The ergot is then digested for

Under the head of Confectiones wo miss the confectio amyg- twelve hours with water at 160°; and the infusion thus obtaineddaJse and conf. aromatica, but find them again further on as is evaporated to half the weight of the ergot employed, andpulvis amygdalæ co. and pulvis cretm aromaticus. Conf. aurantii. mixed with its bulk of alcohol, which precipitates a quantitycassiæ, opii, and rutæ, are omitted, and confectio piperis (the of gummy matter. This fluid extract of ergot is a most reliableold Ward’s paste), if not improved, is at least changed. It form for using this drug.- It was proposed some years ago by- consists now of pepper, carraways, and honey. Mr. Squire, and has been found to represent the ergot mostWe are rather surprised to find a process for digitalinaim, a completely. These fluid extracts are in each case so arranged

substance rarely, if ever, prescribed. We cannot see what is that a fluid ounce represents an ounce by weight of the sub-gained by the use of such powerful concentrations. The tincture stance from which it is prepared. An exception to this rule,of digitalis will answer every purpose to which digitalin can be however, is found in the case of extractum filicis liquidum,applied. If digitalis were ever employed externally, this active which is really only the oil of male fern, and is only liq’id be-principle might be useful ; as it is, we cannot understand its cause it cannot well be solid. It would have been better to-introduction into the Pharmacopœia, call it only extractum filicis, as the term " liquidum" suggests

The directions given by the Pharmacopoeia for preparing the confusion with the true fluid extracts mentioned above.extracts from fresh herbs merit some examination. In previous —

Pharmacopœias the leaves alone have been ordered, to the ex- ..

clusion of the other parts of plants. It is notorious that the PROFESSOR HUxLEY, F.R..S. --- This gentleman will

large makers of extracts have not adhererl to this rule. The resume his lectures in the theatre of the Royal College of Sur-.extract yielded by the other parts of plants has not been geons on Tuesday next, and will deliver twenty-four lecturesrejected by these manufacturers, who have invariably employed "On the Structure and Classification of the Mammalia,"the whole of the soft parts; and the Pharmacopœia has wisely comprising the zoological anatomy of man, with especialconformed its theory to the universal practice. Two questions reference to the bony skeleton and the muscles ; the resem-are naturally suggested :-1stly. Does an extract so made keep blance and difference of the pectoral and pelvic limbs ; thebetter or worse than one made from the leaves alone ? 2ndly. characters and the nomenclature of the teeth ; the brain and,Are the other soft parts of plants inferior to the leaves the organs of sense and voice; the organs of reproduction, andalone in medicinal activity ? A paper read some time ago at a the process of development ; variations of structure. The

meeting of the Pharmaceutical Society by Mr. Squire, the then comparative anatomy of the apes and lemurs ; the Insectivora,president, contains some experiments much to the point. Cheiroptera, and Rodentia ; remarks upon the classification ofBelladonna, on account of the ready way which exists of testing the preceding groups. The Carnivora; the ungulate mammals;it by its effects on the eye, was the case selected for investiga- the Sirenia, Cetacea, and Edentata; the Proboscidea and thetion. An extract was made from the leaves only, and another genus Hyrax ; remarks upon the classification of the preceding,one from the soft tops, including flowers, small stalks, &c. On groups. The Marsupialia; the Monotremata; remarks uponthese extracts being tested by eminent oculists it was found the classification of the mammalia generally.