PATHFINDERS OF PHYSIOLOGY 21 



Reaumur and His Methods. Rene Antoine Ferchault de Reaumur, 

 a Frenchman bom in 1683, and described as one of the most notable 

 men of science of the eighteenth century, is, in chronological se- 

 quence next most important contributor to the physiology of the 

 alimentary tract. His name is already familiar to most of us as the 

 inventor of the Reaumur thermometer. His studies on the gastric 

 juice at this time are all-important, inasmuch as his methods are 

 unique. Reaumur had in his possession a kite and took advantage of 

 the habit of the bird of ejecting from its stomach things swallowed 

 which it could not digest. The kite was fed pieces of meat secured 

 in metal tubes. It was found that meat when ejected had no odor 

 of putrification. Experiments were made with small pieces of bone, 

 which were completely dissolved when ejected and swallowed by the 

 kite several times. On vegetable grains and flour, the fluid of the 

 kite's stomach had apparently little effect. The tubes were filled with 

 small pieces of sponge, which, when ejected, were squeezed out, thus 

 enabling the investigator to procure pure gastric juice and to study 

 it in vitro. He proved that digestion was not putrifaction but some^i 

 thing really opposed to that process. While Reaumur's experiments W 

 left much to be ascertained about gastric digestion, he at least favored \ 

 the solvent power of the succus gatricus, by the employment of a J 

 wholly new method. 



Experiments with Gastric Juice. We must look to Italy for the 

 next contributor to our knowledge of digestion. Parenthetically, it 

 is of interest to note that the idea of specializing, if it had taken root 

 at all at this early time, was not markedly apparent. The worker in 

 the physiology of digestion was equally prominent in almost every 

 other department of physiological research. Lazzaro Spallanzani 

 (1729-1799) was one of the most eminent men of his time. Educated 

 for the church, he was usually known as Abbe Spallanzani. His life 

 was devoted to experiments, researches and teaching. He was pro- 

 fessor at Bologna, and afterwards at Pavia. We find him first ex- 

 perimenting with germ life, with results that disprove the doctrine 

 of spontaneous generation. His researches in other fields showed that 

 he had conceived the truly scientific method. 



Spallanzani took up Reaumur's methods and most of his results 

 were achieved by them. Aided by improvements in chemistry, he 

 was able to make marked advance over his predecessors. His ex- 

 periments were made on all kinds of animals, fishes, frogs, serpents, 

 birds, sheep oxen, horses, cats and dogs, and lastly upon himself. Be- 

 sides hollow tubes, he used hollow spheres, freely perforated, into 

 which were placed meat and bread, bone or grains of wheat, and the 

 results of digestion were studied when these were ejected or procured 

 by opening the animal's stomach. He also attached pieces of meat to 

 threads, which he would draw from the animal's stomach at fixed in- jc 

 tervals. He experimented upon himself by swallowing linen bags con- < 

 taining bread, meat and similar articles, examining the contents after '"1 

 they had been voided per anum. He procured gastric juice from 

 himself by producing vomiting on an empty stomach. He repeatedly 

 tested the action of gastric juice in vitro, keeping the tubes a uniform 

 temperature by retaining them in his arm pit, using the same food 

 covered by water as a control. He found that gastric juice acted 1^ 

 more readily upon finely divided parts of food such as crushed grain ) 



