28 ABSORPTION BY THE DIGESTIVE TRACT 



the stomach has been doubted or denied since Bouley and 

 Colin published the results of their experiments with strych- 

 nine. Bouley, after dividing the pneumogastric nerves, 

 administered lethal doses of strychnine without injurious 

 effect. Colin found that after tying the pylorus, large doses 

 of strychnine introduced into the stomach did not poison ; 

 but later experiments seem to prove that poisoning does 

 not occur when after an interval the ligature is removed, 

 and the contents of the stomach are allowed to pass into 

 the bowel. Schiff considers that absorption of the strych- 

 nine is sufficiently gradual to allow of its being proportion- 

 ately eliminated in the urine, and that the drug does not 

 accumulate in the blood in sufficient quantity to cause 

 poisoning. 



In certain animals (dog, pig, ox, sheep) the empty 

 stomach is supposed to absorb more rapidly than the 

 stomach filled with food : but the empty stomach is less 

 vascular, and its corrugated lining is protected by a thick 

 mucus, which probably retards absorption. Medicines 

 given on a full stomach or mixed with the food are exposed 

 to attenuation and the action of the secretions formed in 

 the digesting stomach, and, if unstable, they may undergo 

 rapid alteration, and fail to produce general effects. Medi- 

 cines intended to act directly on the stomach should be 

 given to the animal fasting, and nutrients should be given 

 with the food or soon after feeding. In gastric impaction 

 medicine given by the mouth seldom acts with the desired 

 rapidity. It mixes with the ingesta, but owing to the 

 movements of the stomach being either diminished or sus- 

 pended, the food does not pass into the intestine, or the 

 drug does not reach the absorbent surface in sufficient 

 quantity, and in consequence its action is delayed. 



Absorption by the small intestine in all the domestic 

 animals is very active. A strychnine salt injected into the 

 duodenum produces its effects in three or four minutes, and 

 ferrocyanide of potassium similarly used may be found in 

 the blood in five to six minutes (Kaufmann). The caecum 

 and large colon absorb rapidly, and in cases of tympany 

 treated by puncture advantage may be taken of the canula 

 to introduce medicines directly into the intestine. The 



