On the Suhjiance of the Brain in a Turkey, a Sheep, and a 



Sparrow. 



IN my examination of a Turkey's Brain, I began with that part 

 which is called the corticle ;* this part, belides the small blood- vef- 

 fels and globules found in it, is compofed of a very pellucid cryf- 

 taJline, and (as it appears to the eye) oily fubftance, which, from its 

 clearnefs and tranfparency, fliould rather be called the vitreous or 

 glafly part, than the corticle or fhell, of the Brain. When I fpread 

 this into fmall particles, I perceived to ilTue from it a fmall quanti- 

 ty of a thin fluid, compofed of very minute globules, thirty-fix of 

 which would not be equal in lize to a globule of the human blood ; 

 this liquor, though it did not extend farther from the brain than 

 about the tenth part of the diameter of an hair, was yet mixed with 

 thofe globules. I obferved this fluid matter principally in the 

 Brains of thofe Turkeys which had been killed fome time, whence 

 I concluded that it had partly iffued from the fmall velfels of the 

 Brain, and perhaps that fome of thofe veflels themfelves might have 

 been diflblved into a fluid matter. Belides thofe fmall globules, there 

 were fome larger ones, of which I judged lix would be equal in 

 (ize to one globule of human blood; thefe two forts of globules I 

 judged might iflue from the minute veflels which I might have 



• That is, tlie fliell or cafe, from the Latin word cortex. livLich figniCea the bark of a 

 tree. 



Vol. II. , N 



