103 



President Snyder introduced the Secretary of Agriculture with a 

 few words of appreciation concerning the long-sustained attitude of 

 the Sccivtary in fostering agricultural chemistry, especially the 

 \\ork of the ollicial chemists, by making possible the close affiliation 

 between the Department of Agriculture and the association. The 

 Secretary then briefly addressed the convention, after which the read- 

 ing of the drug reports was resumed. 



THE NECESSITY FOR ANIMAL EXPERIMENTATION IN DETER- 

 MINING THE PURITY AND STRENGTH OF MEDICINAL PREPA- 

 RATIONS. 



By WILLIAM SALANT. 



Experiments on animals have long been recognized in medical jurisprudence as a 

 valuable adjunct to chemical and microscopical methods in the detection of poisons in 

 animal tissues and fluid. Notwithstanding the improvements in the methods of 

 analytical chemistry witnessed within recent years, tests on animals, or, as Roberta 

 terms it, "hi.. logical testing," is still resorted to in order to corroborate the findings of 

 ih. analytical chemist in cases of suspected poisoning with alkaloids and other 

 substances of plant or animal origin. The French chemist, Boutmy,& 

 who made . -xiensive studies on poisoning with alkaloids, concluded that in all cases 

 in whirh the j.n .- -nee of an alkaloid in the body is suspected experiments on animals 

 should be made for tin- jurjM)e of confirming the results of chemical analysis. 



Tli-- -ome investigators indicates that the biological method is in certain 



owes much more delicate than the chemical. Rankec reports experiments on dogs 



which were given O.I of a grain of strychnin by mouth. Chemical examination of 



; -an.- if these animals failed to show the presence of strychuin, but when extracts 



of the same organs wen- injected into frogs tetanus followed. Falck<* has shown long 



ago that oue-twcnticih of u milligram of strychnin was sufficient to induce tetanus 



in a mcdiiun -i/.cl frog. It might be added that if smaller frogs are used the same 



effect may be obtained with one-eightieth of a milligram. Atropin is another example 



tru_' --I which .-.mall quantities are sufficient to produce a physiological reaction. 



Only one-twentieth of a milligram is necessary to produce dilation of the pupil. 



Likewise cocain, which produces characteristic effects on the mucous membranes, 

 and by iu action <>n the frog's pupil, can be identified, even when very small quan- 

 are present in biological solutions. 



Aconitin can be identified in milligram doses by its action on the tongue, eye, 

 heart, and central nervous system. No chemical methods have as yet been devised 

 by which such small quantities of this alkaloid can be detected. A striking illus- 

 tration of the delicacy of the biological method is afforded by the work of Hunt. 

 In his investigations on the functions of the thyroid he has shown that mice fed for a 

 few days with the extract of this gland acquire greater resistance to poisoning with 

 acetonitrile. One milligram of the official dried thyroid fed to white mice daily for 

 a few days may enable the animals to recover from double the dose of acetonitrile 

 fatal to the controls. Seidell,/ working under the direction of Hunt, found that 

 forty to fifty times as much thyroid would be required to give the iodin test. 



Ber. deutsch. pharm. Ges., 1903, 13: 325. 



ft Ann. hyg. publique med. legale, 1880, [3] 4. 193. 



Virchow's Archiv, 1879, 75: 20. 

 d Vierteljahrschr. gericht. Med., N. F., 1874, 20: 198. 

 'J. Amer. Med. Assoc., 1907, 49: 240. 

 /Ibid. 



