133 



cases prefer to add an equivalent amount of fiftieth-normal acid as a quantity less 

 liable to error in measurement. 



In < II i Mr. Blome suggests increasing the amount of ether-chloroform mixture for 

 ex. radii,- ih- drug to 180 cc and decanting 120 cc. Mr. Fuller suggests that instead 

 of din-, tin- the use of neutral alcohol for dissolving the alkaloid before titration it 

 would be preferable to compare the result with that of a blank titration made with the 

 same amount of the same stock of alcohol, water, and indicator. Mr. Hankey reports 

 di-aiisfadion with the titration results owing to an indefinite end reaction. Though 

 his alcohol was redistilled over alkali, a blank titration with the amounts of acid, 

 ulrohol. and water direct, ,1 required only 14.3 cc of fiftieth-normal alkali, while the 

 -ame amount of acid by direct titration required 15 cc of the standard alkali. Mr. 

 Parker prepared neutral" alcohol by adding fiftieth-normal potassium hydroxid to 

 alcohol until a I. lank titration with the amounts of acid, alcohol, and water directed 

 agreed with a direct titration of the acid alone. This method or that suggested by 

 Mr. Fuller eliminates the effect of any deviation from neutrality by the alcohol or 

 water under the working conditions. Mr. Lyons made a parallel experiment, evap- 

 orating th- eth.-r chloroform extract of the drug instead of shaking out with acid 

 and titrating the re.-idue directly, as outlined in the discussion under aconite root. 

 The re-nit wa.- !>:;_' p.-r cent . 



BELLADONNA ROOT. 



This sample was delivered as No. 60 powder,and passed through the several sieves 

 in the following pro|M>rli>n- 



Grams. 



SO 98 



No. 60 1 



Total. 



It was, then-!'.. re. -'inewhai liner than the Pharmacopeia requires for assay samples 

 "i 'I"- dru.' P.\ Method Id'. S p. . d the tew gravimetric results 29 per cent came 

 within 10 per .mt ..f the average and 43 per cent within 15 per cent. Of the volu- 

 metric result*, 46 JMT cent came within 10 per cent of the average and 80 per cent 

 within r> per cent, My (II) the gravimetric results varied more than the similar 

 detrrminatii.n- l.y I . Th- volumetric results by (II) were decidedly better than 

 the cORQBponding results by (I), 73 per cent coming within 10 per cent of the average 

 and 80 JKT cent within 1"> per cent. The averages by the two volumetric determina- 

 tion- are practically identical, likewise those by the two gravimetric determinations, 

 Inn no explanation is apparent for the fact that by both methods the gravimetric 

 result.- average lower than the volumetric. This relation occurs also in four instances 

 i in II where the results apparently represent the same residue. 



In I Mr Hank. \ d;--ol\vd the alkaloidal residue in Ice of neutral alcohol before 

 adding excess of standard acid and titrating back with half-strength limewater, com- 

 paring the same with a blank titration. C. H. La Wall made parallel assays by 

 both methods, evaporating the ether-chloroform extract instead of shaking out with 

 acid, and titrating the impure residue directly, the results obtained being (1)0.514 

 and (II) 0.529 per cent, duplicate results agreeing well. J. G. Francis used 25 cc, and 

 Mr. Parker 50 cc more ether-chloroform mixture than the amount directed to extract 

 the driu,'. Their results are all well above the average. The remarks made in the 

 discussion on belladonna leaves, Method I, regarding the percolation of the drug 

 also apply to belladonna root. With belladonna root Method II, by evaporation of 

 th. ether-chloroform extract, and direct titration of the impure residue, Mr. Lyons 

 obtained a value of 0.617 per cent. 



