66 



C. U' C. P. ALUMNI JOURNAL 



Assay of Minute Quantities of 

 Arsenic. — J. Z., New York desires in- 

 formation concerninj^ the assay of min- 

 ute quantities of arsenic such as are 

 necessary in investigations as to the fate 

 of salvarsan and similar arsenical or- 

 ganics in the animal body. A chemical 

 method — destruction of tissue with potas- 

 sium permanganate, removing excess of 

 permanganate with hydrogen dioxide 

 and eventual titration of the arsenical 

 distillate with hundredth-normal iodine 

 and thiosulphate solutions — has been 

 worked out by Rupp and Lehmann and 

 can be found in full in the Archive der 

 Pharmacie 350 1912 382 and 251-1913-1. 

 These may be consulted by our queriest 

 in the College Library or will be trans- 

 lated for an appropriate fee. An inter- 

 esting type of qualitative test for minute 

 amounts of arsenic is that devised by 

 Gosio (Berichte dtsch. CIi. Gesell. 30- 

 1 897-1 024) and modified by Maassen 

 {Chem. Centralblatt /j 1^02-1243). This 

 is based upon the fact that certain 

 moulds (notably Penicillium brevicaule) 

 grown upon media containing minute 

 amounts of arsenic produce volatile 

 arsenic compounds possessing a garlic- 

 like odor. It is claimed that i/ioo milli- 

 gramme of arsenic can be detected in this 

 manner. 



Legal Queries.— During the month, 

 we have answered a number of queries 

 relating to pharmacy laws, local, state, 

 and national, emphasizing each time that 

 the information given was merely the 

 personal opinion of a layman. For this 

 reason we do not print such answers, 

 since in serious legal matters a lawyer 

 should be consulted. 



Hydrogen Dioxide Literature. — M. 



A. C, New York, desires articles dis- 

 cussing at some length, the manufacture 

 of solutions of hydrogen dioxide. The 

 two most satisfactory articles on this 

 subject with which we are acquainted 

 are one of G. C. A. Fawsett (//. Soc. 

 Chem. hid. 21-1902-229) and another by 

 J. S. Brewer (Drug Circ. 56-1912-601). 

 Both of these are to be found in the 

 College library and are therefore at the 

 disposal of our querist. 



Detection of other Cinchona Alka- 

 loids in Quinine. — G. H. S., New York, 

 desires the test given in the fifth edition 

 of the German Pharmacopoeia for de- 

 tectins: the presence of other cinchona 

 alkaloids in quinine sulphate. This is a 

 modification of the well-known Kerner's 

 test and reads as follows : 



"Two grammes of the sulphate dried 

 between 40° and 50° are placed in a 

 test-tube, 20 cc. of distilled water are 

 added and the mixture is warmed for 

 one-half hour with frequent shaking in 

 a water bath heated between 60° and 

 65°. Then the test tube is placed in 

 water chilled to 15° and is kept therein 

 for two hours with frequent shaking. 

 The mixture is then transferred to a dry 

 piece of linen of about 100 square centi- 

 meters surface and is expressed, the 

 strained liquid being then filtered through 

 a paper of 7 centimeters diameter. Five 

 cubic centimeters of the filtrate cooled to 

 15° are mixed with 4 cc. of 10 per cent, 

 ammonia water, whereupon there is 

 formed a precipitate which ■ must upon 

 gentle agitation, redissolve forming a 

 clear fluid." 



If other cinchona alkaloids are present, 

 the precipitate will not wholly dissolve. 



