vm] in the Eighteenth Century. 213 



zani ; but nearly the whole of his energy was thrown into the 

 investigation of problems of natural history. His works on 

 Reproduction brought him great fame ; his contributions to the 

 physiology of the circulation were considerable; he travelled 

 much and worked at geological problems ; and just before his 

 death he carried out researches on respiration in which he made 

 a notable addition to that part of physiology for which Lavoisier 

 had just done so much. But here I wish to speak only of his 

 contributions to the physiology of digestion, his first memoir on 

 which was published in 1777, the year of Haller's death, others 

 following in the succeeding years. 



He took up again Reaumur's method, and most of his results 

 were gained by it, though he also adopted other methods. 

 Finding the knowledge of the subject almost in the condition in 

 which Reaumur had left it, he was able by his numerous experi- 

 ments, aided by the improvements in chemistry since Reaumur's 

 time, to make a great advance over his French predecessor. 



He experimented with all kinds of animals (and he was it 

 may be noted not a mere physiologist but a naturalist, one 

 who studied animals (and plants) from various points of view), 

 fishes, frogs, newts, serpents, birds of various kinds, sheep, oxen, 

 horses, cats, dogs, and lastly himself. He at least ran no 

 risk of going astray by making deductions based on results 

 gained with one kind of animal ouly. 



He employed largely as I have said Reaumur's method. 

 He made use of metal tubes, closed by a grating at each end ; 

 but in order to allow the freer entrance of fluid he also made 

 perforations in the walls. Sometimes he used hollow spheres 

 made of two hemispheres screwed together, the walls being 

 freely perforated. These tubes or spheres he filled with pieces 

 of meat, bread or bone, or grains of wheat and the like. He 

 recovered them in the case of carnivorous birds through their 

 being rejected by the mouth ; in the case of other animals he 

 opened the stomach after the lapse of a given time. 



He also made animals swallow pieces of meat or the like, 

 so attached to threads or wires that he could after a while 

 withdraw them from the stomach. 



On himself he experimented by swallowing small linen 



