40 VETEKINAEY TOXICOLOGY 



An interesting case of poisoning by absorption is noted 

 by Mahon,^ in which arsenic was used in mistake for zinc 

 sulphate in a case of greasy heels. The condition was 

 obstinate, but ultimately yielded to treatment. 



Wallis Hoare has observed colic and purgation caused in 

 a horse by the application of a strong arsenical ointment to 

 raw warts. The trouble gradually passed off after removal 

 of the dressing. 



Cases of poisoning by copper arsenite, or Scheele's green, 

 used in colouring wall-paper, have been observed in the 

 donkey and ox,^'® and a case of poisoning of sheep by lead 

 and arsenic has been communicated by Dunstan. 



As regards dips, a lengthy report of a legal action is 

 given in the Veterinarian of 1858, in which the conflicting 

 expert opinion and the difficulty of experimental verification 

 are well illustrated. The plaintiff lost 850 out of 869 sheep 

 within two or three days after dipping in a dip containing 

 2^ pounds of arsenic per 100 gallons. He obtained a 

 verdict, though others had safely used the same or similar 

 dips ; and Gamgee, Macadam, and Dun failed to secure 

 experimental poisoning with even stronger solutions. The 

 strength noted is regarded generally as safe, when properly 

 used. 



Most authorities are agreed that there is no danger of 

 absorption of arsenic in toxic doses from dips through the 

 unbroken skin. Absorption to a certain extent must, how- 

 ever, occur, and H. E. Laws,* of Messrs. Cooper, holds that 

 the killing of the parasites is caused by their taking up 

 arsenic from the blood stream of the host. In dipping the 

 solution ought not to contain more than 5 pounds of arsenic 

 per 100 gallons, each sheep being immersed for from forty 

 to sixty seconds and requiring 1 gallon. The solution 

 must be as completely squeezed out of the fleeces as 

 possible, and the animals turned out, if possible, on to a 

 dry road or large yard free of hay, litter, vetches, or green 

 food. Accidents arise chiefly from the licking of tiie fleeces 

 when the sheep are overcrowded, and from the drippings 

 * Private commuiiication. 



