214 The Physiology of Digestion [lect. 



bags containing meat, bread, &c, and examining the contents 

 after they had been voided per anura. Greatly daring he 

 swallowed perforated tubes, made not of metal but wood ; and 

 these he successfully recovered without suffering any harm. 



He obtained what he speaks of as gastric juice by making 

 animals swallow on an empty stomach tubes containing sponges. 

 On recovering the tubes he found that the sponges had imbibed 

 a considerable quantity of fluid, which he squeezed out. From ' 

 himself he obtained gastric juice by making himself vomit on 

 an empty stomach before breakfast ; but this mode of experi- 

 mentation was he says so disagreeable that after two trials he 

 gave it up. 



The action of the gastric juice so obtained he tested on 

 various articles of food in vitro, exposing tubes containing the 

 juice and food to warmth either by keeping them in his own 

 armpit for two or three days, or by placing them in a stove, 

 and always using as a control the same food covered with simple 

 water. 



By a very large number of experiments carried on in*£hese 

 various ways he confirmed and greatly extended Reaumur's 

 results. He found that in all animals food is in the living 

 stomach dissolved " into the pultaceous mass called chyme " by 

 the juice to whose action it is there subjected; and that this 

 juice is a solvent of all kinds of food, animal and vegetable, 

 bone included, though some things or parts are more soluble 

 than others. He found that the juice was more active on 

 divided parts, such as crushed grains, or broken bones, than on 

 whole solid parts, such as whole bones, or whole grains ; from 

 this he concluded that "trituration is merely a preparation 

 " for solution and does not itself constitute the digestive 

 "process." He was led by his numerous experiments to the 

 same conclusion as Reaumur, that while gastric juice was a 

 solvent of all kinds of food, the juice of this or that animal 

 was more specially active on the natural food of the animal, 

 that the juice of the herbivorous animal for instance was more 

 active on vegetable food. Recalling Reaumur's experiment of 

 giving green plants or hay to sheep in tubes, he repeated the 

 experiment and obtained at first similar negative results, even 



