218 DIGESTION. 



those who suspected the existence of a solvent fluid was at it8 

 height, Reaumur first obtained what is now known as the 

 gastric juice, and demonstrated some of its solvent properties. 

 In a paper presented to the Academy of Sciences of Paris, 

 on the process of digestion in birds, he showed that meat 

 enclosed in a tin tube so arranged as to permit the entrance 

 of liquids, when forced into the stomach of a buzzard, became 

 softened and partly digested after remaining in the organ for 

 several hours. Substituting small pieces of sponge for the 

 meat, he obtained a few grains of gastric juice, in which 

 he noted a well-marked acid reaction ; but the quantity ob- 

 tained was not sufficient to allow of any satisfactory experi- 

 ments on artificial digestion. 1 This was the first time that 

 the presence of a solvent fluid in the stomach had ever been 

 experimentally demonstrated, and the fluid was the first spe- 

 cimen of gastric juice ever obtained. The experiments on 

 birds were repeated by Reaumur, in an imperfect manner, 

 on dogs and sheep, with analogous results. 



The celebrated observations of Stevens, in l^YT, were 

 even more conclusive with regard to the presence of solvent 

 fluids in the alimentary canal. He had under observation a 

 juggler, who, in his performances, was in the habit of swal- 

 lowing stones and other hard articles. For the purpose of 

 ascertaining whether food could be dissolved in the alimentary 

 canal if removed from all triturating action, Stevens con- 

 structed little hollow balls of silver and of ivory, pierced 

 with numerous small holes, and capable of being opened by 

 a screw in the middle, which he caused the man to swallow 

 after they had been filled with various articles. 2 After a 

 number of hours, from thirty-six to forty-eight, the balls 

 were passed by the anus entirely empty, except when they 

 had been filled with hard grains, which were only a little 



1 REAUMUR, Sur la Digestion des Oiseaux, Second Memoire. Histoire de 

 I* Academic Royale des Sciences, Paris, 1752, pp. 461-495. 



3 STEVENS, De Alimentorum Concodione, Edinburgh, 1777, in SMELLIE'S Thes. 

 Med., quoted by TIEDMANN AND GMELIN, op. cit., premiere partie, p. 365, note. 



