34 VETERINARY TOXICOLOGY 



by the mouth.* In very fine division, or in solution, and 

 particularly in the form of alkali salts, the arsenious 

 compounds are most readily absorbed and most toxic. 

 Absorption through the unbroken skin may occur when 

 an arsenious solution has remained for a long time in 

 contact therewith, and accidents have occurred to sheep- 

 dippers from this cause. 



Arnold Theiler," experimenting in South Africa, has 

 published the results of a large number of tests made to 

 ascertain the safe dose of white arsenic (arsenious oxide). 

 Cooper's dip (an alkaline arsenite and thioarsenite with 

 sulphur), and bluestone (copper sulphate) for sheep. All 

 these substances are common remedies for intestinal 

 parasites, and are largely used and easily procurable. 

 Theiler's results have added value by reason of the fact 

 that he was able to use large numbers of animals in his 

 tests. For each dose thirty sheep were used. All were 

 watered twenty-four to twenty-eight hours before dosing, 

 fifteen immediately after, and fifteen within twenty-four to 

 twenty-eight hours after. Theiler does not appear to have 

 reckoned on the sparing solubility of white arsenic, for he 

 remarks on the extraordinary circumstance that doses 

 varying from 7^ to 150 grains failed to kill in special tests 

 designed to disclose the toxic dose. In the larger scale ex- 

 periments, two of fifteen sheep, which had 60 grains each, 

 followed at once by watering, died, one on the seventh and 

 the other on the eleventh day, both showing perforation of 

 the fourth stomach, peritonitis, and gastro-enteritis, with 

 pale yellow liver. As abundant examples prove, these are 

 not invariable signs of acute poisoning, and the results 

 Theiler got must be held to illustrate slow poisoning, 

 probably with lodgment of coarser particles in the ali- 

 mentary tract. As regards Cooper's dip, Theiler concludes 

 that 15 grains is a safe dose. He found that 30 grains 

 killed 1 in 48; 45 grains killed 4 in 30; and 60 grains 

 killed 14 in 15 watered at once after dosing, and 6 of 15 

 watered twenty-four hours after dosing. Whereas the 

 * See Bevue Generate de Medecine Veterinaire, February, 1911. 



