2^^ 



TtiE PHILOSOPHY 



Iv performed every twenty-four hours ; but, In crows, it 

 happens at lead every nine, and not unfrequently every two 

 or three hours. 



Spalanzani, as in the former experiments, thrufi; dov>'n 

 perforated tubes, filled with different fubftances, into the 

 flomachs of crows. Thefe tubes were uniformly thrown up 

 by the animals in a few hours. When the tubes v/ere filled 

 with entire grains, as wheat or beans, he found that the gaf • 

 trie juice, though the tubes, being repeatedly forced down, 

 continued in the flomach for the fpace of forty-eight hours, 

 had exerted no folvent power. As the huHvS of the feeds 

 reiliied the aclion of the gaftric juice, he bruifed them, and 

 i-epeated the experiment. * Four tubes full of this coarfe 

 « liour/ f;\ys he, * were given to a crow : They remained 



* eight hours in the ftomach, and proved the juftnefs of my 



* fufpicion ', for, upon examining the contents, I found a- 



* bove a fourth part wanting. This could arife from no 

 « other caufe but folutlon in the gaftric liquor, v/ith which, 

 ^ the remainder was fully impregnated. Another obferva- 



* tion concurred in proving the fame propofition : The larg- 



* eft bits of wheat and bean were evidently much diminifh- 



< ed : This muft have been owing to the gaftric liquor hav- 

 ^ ing corroded and diiTolved good part of them, as the nitrous 

 « acid, diluted with a large quantity of water, gradually con- 

 ^ fumes calcareous fubftances. I replaced what remained of 



* the feeds in the tubes, and committed them again to the 



* ftomach, wherein they remained, at different intervals, 



< twenty-one hours ; at the end of which period they were 



* entirely diffolved ; nothing being left but lome pieces of 



* hufk, and a few inconfiderable fragments of the feeds. 

 « Wheat and beans floating loofe in the cavity of the ftom- 

 « ach, undergo the fame alteration as in the tubes. When 

 « I fed my crows with thefe feeds, I obferved, that, before 



* they fwallowed them, they fct them under their feet, and 



