c u y 
It was for thefe Reafons, and to avoid' Prolixity, 
that the Gall fpilt on the outfide of the Intejines, 
was not taken Notice of in that Eflay. 
The fecond Difficulty is how a frefh Recruit of 
Chyle fhould be a Caufe of Sleep. 
The Experiments which I made before this Society , 
as printed in Tranfaff. N°. 424, I hope may ferve to 
juftify what I fhall here a flume, concerning the Na- 
ture and Exiftence of the nervous Fluid , or animal 
Spirits, in the Solution of this fecond Difficulty. 
The Argument which has been offer’d, runsthus: 
It is well known that People after eating plentifully 
are often inclined to Sleep, long before the Chyle can 
be fuppofed to be got into the Blood ; therefore a frefh 
Recruit of Chyle cannot be the Caufe of Sleep j but 
there muft be fome other Caufe, at leaft at that 
time. 
Which Caufe isafligned by fuppofing, that after a 
plentiful Meal the diftended Stomach will load and 
opprefs the defcending Aorta, fo as to hinder the 
Blood in its Defcent, and thereby force a greater 
Quantity than ufual into the Aorta Afcendens , 
which by its diftended Branches in the Brain will ob- 
ftruffc the Secretion of the Animal Spirits through the 
Glands of the cortical Subftance into the Origin of 
the Nerves , and thereby produce Sleep. 
This being generally efteemed a mechanical Ac- 
count of the Caufe of Sleep after Meals, deferves the 
greater Attention. 
In anfwer to which, if fuch was the true Caufe of 
Sleep after Meals, it ought to have the fame Effeffc 
upon the Cerebellum , from whence moft of the 
Nerves^ that ferve in the natural and vital Fun&ions, 
B % arife 
