UPON THE FATE OF ARSENIC AFTER INGESTION 

 BY, AND INJECTION INTO, LIVE-STOCK. AND 

 AFTER ABSORPTION THROUGH THE SKIN IN 

 DIPPING. 



B}- Henry Hamilton Green, D.Sc, F.C.S. 



{Abstract.) 



{Prhitcd ill Ainiiial Report of the Director of i'ctcrinary 



Research, Pretoria. ) 



Experiments have been carried ont on sheep, horses, and 

 cattle, the bulk of the data being derived from experimental 

 work on the administration of arsenite in the treatment of wire- 

 worm {Hcenioiicliiis contortiis) in sheep. Numerous protocols 

 are presented to show the distribution of arsenic in the stomach 

 system and intestinal tract at various intervals after dosing, 

 and the rate oif elimination in urine and fceces is dealt with in 

 considerable detail. The distributicjn of arsenic in the ditterent 

 compartments of the stomach of the sheep depends upon the 

 path taken in swallowing. If the animal takes material volun- 

 tarily, as in the form of a lick, the greater proportion passes into 

 the rumen, and thence slowly through the abomasum into the 

 intestine. If the animal is forcibly dosed, as with a si)ot)n. the 

 path is more arbitrary, and a considerable portion may pass 

 direct to the abomasum. from which it is more rapidly passed 

 on into the intestine. Duration of sojourn of arsenic in the 

 stomach system is discussed. 



Rate of absorption and elimination of soluble arsenic is 

 rapid, and the path of elimination of either arsenite or arsenate 

 of sodium is chiefly b}- the kidneys, about four-tifths of the dose 

 appearing in the urine, and only one-fifth (or less) in the fjeces. 

 With arsenious oxide })owder. absorption is slow, and the relative- 

 proportions eliminated in faeces and urine are reversed. 



After administering soluble arsenite by the mouth. 25-45 

 per cent, of the dose may be eliminated in the urine within 24 

 hours, and as much as 60 per cent, within 48 hours. By the 

 fourth day the rate of elimination falls to a few per cent, of the 

 dose, and thereafter there is a gradually decreasing output, 

 which tails off to a fraction of a milligram per day after eight 

 or nine days. Traces of arsenic, however, are frequently detec- 

 table for another week or two, but the amount is too small ti» 

 be of any physiological consequence. In the faeces the maximum 

 output usually occurs in the third day. and 'by the seventh or 

 eighth day the solid excreta are practically arsenic- free. 



When soluble arsenite is injected straight into the blood- 

 stream the path of elimination is almost wholly through thc 

 urine. the amount entering the gastro-hepatic circulation being 



