December i, 1882.] 



THE TROPICAL AGRICULTURIST. 



507 



There was no quinine in those days, or probably the 

 parallel with our present experience woulct have been 

 complete ; but hariny no substitute the common sense of 

 the 17th century set an example to the science of the 

 VJth. It discarded the worthless barks and supplied itself 

 with others of suitable alkaloidal standard assayed by 

 the fever test. In these days of practical science brokers 

 sell and quinine makers buy cinchona bark on the basis 

 of its alkaloidal percentage, ascertained by exact analysis. 

 The pharmacist alone buys hap-hazard the " showy barks," 

 often very poor in alkaloids, and hence known as " druggists' 

 barks," which the quinine makers are only too happy to 

 leave for him and the dealers only too pleased to get 

 rid of, though for pharmaceutical purposes percentage of 

 alkaloids is more than a relative test of value, — it is an 

 absolute test of fitness. 



The very reverse ought to prevail ; the pharmacist 

 should secure the first choice by being willing to give a 

 better price than the quinine makers, who can only give 

 the alkaloidal value, which is literally the intrinsic value 

 of a part of its constituents. Under this .system the 

 pharmacist would get much better value for his money 

 than he does now by buying a " showy bark destitute of 

 alkaloids," I have heard of a time-honoured establish- 

 ment, which I must not further particularize, buying 

 several serons of calisaya bark at 3s. 6d. lb., which proved 

 to contain not a particle of quinine and only a very 

 small amount of cinchonine. Its assay value certainly 

 would not have exceeded 6d. This i.s a sort of bark which 

 should be left for the stores, whom it would exactly 

 suit, and where no questions are asked. 



The question then is *• What standard should be adopted 

 for the cinchona of pharmacy ? " 



First, it should be an alkaloidal standard, not a quinine 

 standard. 



Secondly, it should be a mean and not an extreme 

 standard. 



And, thirtUy, it should be catholic, admitting barks 

 from all sources without arbitrary geograpliical distinctions, 

 which, originally intended as definitions, have now become 

 irrational limitations. 



At the Conference of 1878, Mr Umney spoke of Bast 

 India bark containing 5 or 6 per cent of quinia as the 

 future som'ce of fine fluid extract, and, if of fluid extract, 

 of other pharmaceutical preparations. Assuming him to 

 have meant 5 or 6 per cent of mLxed alkaloids, that would 

 be a reasonable standard to insist upon, — say a minimum 

 of 5 per cent, which holds a mean place between the 

 extremes. I have computed the actual average of ninety- 

 three lots offered on sale by the Dutch Government last 

 year, and find that it is exactly Iv per cent. The highest 

 quality reached 98 per cent, the lowest touched 1 '2 per 

 cent, giving a mean of o' 5 per cent. The mean of the 

 two results is therefore 5' 1 per cent. 



It remains to be considered how this standard should 

 be secured, for it is to be feared that pharmacists gener- 

 ally do not submit their purchases of cinchona to the 

 pharmacopcoial test, and it is as well to acknowledge that 

 refined tests are not pratieable in the pressure of daily 

 business Mr. Holmes, probably haring this difiiculty 

 in view, suggested that the wholesale druggists shoidd be 

 required to state the percentage; of a Ikaloids in the samples 

 they offer, but this is scarcely sufficient for the protection 

 or for the credit of the pharmacist. 



The same difficulty seems to have presented itself to 

 Messrs. Squibb, of New York, who have endeavoured 

 to meet it by publishiug what they consider a simple, 

 easy process of assay suited to the wants and the skill 

 of well-trained pharmacists who are not expert quino- 

 logists. Whether the process possesses the desired quali- 

 ties of simplicity and facility may be judged by peru.sal 

 of the description at p. 77 of the third number of Messrs. 

 Squibb's ' Ephemeris.' 



In pursuit of a similar object I have been led to prefer 

 the more simple hydrochloric acid process, which I tried 

 on the recommendation of Dr. De Vry, in his laboratory 

 at the Hague, and with the advantage of his assistance. 

 The modus operandi finally adopted is as follows : — 



Take 25 grams finely powdered cinchona bark, mix 

 with 2-5 c.c. strong hydrochloric acid (=2 6 c.c. E.P. 

 strength) in 30 c.c. distilled water, or just so much as 

 suffices to moisten the bark ; set by for two hours, add 



100 c.c. distilled water and let stand for twelve hours or 

 more, stirring occasionally, until all foam disappears from 

 the surface. Pour into cylindi-ical glass percolator, the 

 mouth of which has been stopped by a pinch of eharpi 

 loosely drooped into it and moistened with a little water, 

 and recover the clear percolate. Pour on more water 

 until the percolate ceases to be precipitated by caustic 

 soda. In this w.ay about 300 c.c. are recovered. Precipi- 

 tate with caustic soda iu considerable excess. Set the mix- 

 ture by for twelve hours, when it will be found that the 

 alkaloids have settled in a compact coherent stratum from 

 which nearly the whole of the supernatant may be de- 

 cauted. The decantate must be reserved. The precipi- 

 tate is then poured upon a filter and washed with a 

 little weak solution of soda to remove traces of cinchona 

 red ; finally it is washed with a little distilled water the 

 whole of the washings being added to the decantate' and 

 the measure noted. When the precipitate has drained it 

 is to be carefully transferred to a tared procelain dish 

 dried over water-bath and weighed. The weight should 

 not be less than 1'25 grams, corresponding to 5 per cent 

 mixed alkaloids. But this will not be an exact indica- 

 tion of the alkaloids contained in the bark, as an appre- 

 ciable quantity remains dissolved in the mother-liquor. 

 Practically this may be estimated as 0'05 grams in 100 

 c.c, which shoidd be added to the ascertained weight of 

 the precipitate, and the sum multiplied by 4 gives a very 

 close approximation to the true percentage, quite near 

 enough for pharmaceutical purposes. When greater ac- 

 curacy is desired the mother-liquor is treated with benzol 

 and the alkaloids are recovered by operations which it 

 is not necessary to describe as they need not be employed 

 in pharmaceutical assays. 



The merit of the above process is its simjihcity and 

 facility of manipulation ; the several stages may be set 

 going as opportunity offers, and they proceed automatically 

 without withdrawing the operator from other duties. Second- 

 ly, the results correspond with the amount of alkaloids 

 which can be extracted in practical operations. 



If it were not for the title of this paper there would 

 be no reason for saying anything about the pharmaceutical 

 preparations of cinchona. As it is, a very few words will 

 suffice. It is notorious that they do not meet the de- 

 mands of modern medical practice. Cinchona won its 

 reputation by administration in the form of powder, it 

 has lost it by the substitution of inferior preparations 

 of inferior bark. The tincture, decoction and iniusion of 

 former generations have had their day and are becoming 

 obsolete, never again to find favour with prescribers, jjliarma- 

 cists or patients. They are all too feeble in alkaloids for 

 administration when the specific effects of cinchona are 

 iu question. Their qualities and their condemnation will 

 be foimd in a paper by Mr. Ekin in fhrtrm. Joiirn., vol 

 ix., p. 213. Nor can it be necessary to pour more obloquy 

 upon the much abused fluid extract, which has never yet 

 found a single defer.d_>r. Its poverty and its wastefulness 

 have been often told. The best that can he saiil for it 

 is that when carefully prepared from barks of suitable 

 quality (which does not mean barks rich in alkaloids) it 

 possesses agreeable astringent properties associated with 

 an unimportant amount of alkaloids which render it ac- 

 ceptable as a vegetable tonic, but it leaves the major 

 part of the valuable and characteristic cinchona principles 

 in the imperfectly exhausted bark. 



Fluid extracts are the pharmaceutical preparations of 

 the d,\v. Their convenience commends them equally to 

 the medical practitioner, to his patient and to the dispen- 

 ser, an I the demand for them is not likely to be diverted • 

 but a iluid extract of cinchona, worthy of its name i,s 

 stiU a desiideratura in pharmacy. ' 



The President proposed a vote of thanks to Jlr. Giles 

 He fenred the present was not the proper occasion for- 

 going into any question as to what principles the cin- 

 chona bark owed its therapeutical properties to ; their 

 time would not suffice to discuss that, even if theV had 

 sufficieut medical knowledge to do so ; but several import- 

 ant pharraaceuti(^al questions hail been brought forward 

 in the course of the paper, and those might very pro- 

 fitably be discussed. 



Mr. Wellcome said the subject of sujiplying chemi.sts 

 with bark of definite alkaloidal strength for dispenshig 



