OF NATURAL HISTORY. 237 



* reduced them to pieces by repeated ftrokes of their long 

 « and heavy beaks : And now they digefted them very well ; 

 f nay, this procefs was very rapid in comparifon of that 



< which took place within the tubes. But, when the birds, el- 

 « ther from exceffi ve hunger, or violence, fwallowed the feeds 



< entire, the greateft part of them pafled out entire at the 



* anus, or were vomited. We cannot, therefore, be fnrprif- 



< ed, that the gaftric juice could not diiTolve them v/ithin 



< the tubes, Unce it was incapable of effe(^l:ing this procefs 



< within the cavity of the ftomach, where its folvent power is 



< far fuperlor.' 



Similar experiments were made with French beans, peafe, 

 nut-kernels, bread, apples, and different kinds of flefli and 

 fifh, all of which were diffolved, both in tubes, and in the 

 cavity of the ftomach, by the gaftric juice. 



Spalanzani finiflies his experiments on digeftion with 

 thofe animals which have thin membranous ftomachs. This 

 clafs comprehends an immenfe number of fpecies, as man, 

 quadrupeds, fifhes, reptiles. In thefe the coats of the ftom- 

 ach feem to have little or no action upon their contents, the 

 gaftric juice being fully fufiiclent to break down the food, 

 and reduce it to a pulp. 



With regard to man. Dr. Stevens, in an Inaugural Differ- 

 tation concerning Digeftion, publKlied at Edinburgh in the 

 year 1777, made feveral experiments upon a German, who 

 gained a miferable livelyhood by fwallowing ftones for the 

 amufement of the people. He began this ftrange praflice 

 at the age of feven, and had at that time continued it about 

 tv/enty years. He fwallowed fix or eight ftones at a time, 

 fome of them as large as a pigeon's egg^ and paffed them in 

 the natural way. Dr. Stevens thought this poor man would 

 be an excellent fubjedl for afcertaining the folvent power of 

 the gaftric juice in the human ftomach. The Doctor, ac- 

 cordingly, made ufe of him for this purpofe. He made the 



F F 



