124 PHILOSOPHICAL TRANSACTIONS. [anNO 1684-5. 



cerning the same. As to the remaining substance of the cortical parts, I could 

 discern no difference from the brain of other animals; but that there was not 

 such a quantity of fluid matter as in animals which had been longer dead. I 

 found also the medullary substance of the brain to be such as I have before 

 mentioned in a sheep ; for it had very white streaks in the parts from whence 

 the medullary spinalis takes its rise, this extreme whiteness was from several 

 very transparent vessels, which lay close to each other, and seemed to me only 

 made to carry the matter by which the medulla spinalis and nerves are partly 

 nourished and maintained. 



I have also examined the vitreous or transparent parts of the brain of several 

 sparrows immediately after being killed, and have therein not only clearly dis- 

 cerned a great number of small blood vessels, as in a turkey, but as plainly as 

 in an ox or sheep. Also the other parts of the brain of a sparrow were very 

 near of the same size with those of an ox, there being no other difference, the 

 great blood-vessels excepted, but that these consisted of a greater number of 

 . the same parts. There were also in the cortical parts an incredible number of 

 extremely small vessels, lying so close to each other, that by reason of their 

 transparency they looked like glass. 



I have lately examined the crystalline humour of the eye of a man, that I 

 might know whether the small threads of the scales wind about in the same 

 manner as I have formerly described them in the eyes of beasts ; but I could 

 not discern the true constitution thereof, notwithstanding I have twice endea- 

 voured it. This I observed, that the crystalline humour was not fine and clear, 

 but yellowish, whereby it differed from the eyes which I had formerly seen of 

 other animals. 



A relation of mine, much troubled with the gout, has his heel spoiled by the 

 great quantity of chalk that breaks out of it; this matter I examined in my 

 method, and separated the same into three parts; the first was the driest and 

 whitest, composed of small irregular parts, as if some small sands lay together, 

 these through the microscope appeared very dark bodies, and each of them con- 

 sisted of a great number of long transparent figures, which I can liken to no- 

 thing better than to cut horse-hair, something sharp at both ends. These 

 figures I judged so thin, that more than 1000 of them lying close together 

 would not equal the thickness of a head-hair. The 2d sort of this chalky matter 

 not so white as the former, contained the forementioned irregular parts of long 

 figures, in a very tough clear matter, mixed with blood-globules, and many of 

 the small roundish parts. The 3d sort was, to the naked eye, somewhat red- 

 dish, caused by the many blood-globules, mixed throughout the slimy matter in 

 the chalk ; it was also constituted of the beforementioned roundish parts. 



