VOL. XIV,] PHILOSOPHICAL TRANSACTIONS. §5 



seen people, who listening with attention to a discourse have closed their eye- 

 lids, according to my calculation, 6000 times in an hour; whereas others stand- 

 ing by them closed them not above 2000 times in the same time. 



Since I wrote to Mr. Oldenburg, in the year l673, that the matter causing 

 the redness of our blood was constituted of globules; I have examined the blood 

 of oxen, sheep, and rabbits, and have observed no difference in magnitude 

 between the globules of those animals and those of men; so that I conceived 

 that the matter which in general made all blood red was globules. But after I 

 had tried the blood of a salmon, a cod, of frogs, &c. and found that the matter 

 which caused the redness therein was made up of parts oval and fiattish, as be- 

 fore said, I examined the blood of several birds; and have also observed, that 

 the matter causing the redness of their blood, was also composed of like flattish 

 oval parts, with those of fishes. So that I now concluded, that all animals, 

 whether birds, Hsh, or other creatures that live in the water, have the parts 

 causing the redness of their blood, consisting of the said flattish oval parts, 

 and if hereafter I chance to find the contrary, I will inform you of it. 



On the rising and falling of the Quicksilver in the Barometer. By Dr. Martin 

 Lister, F.R.S. N° l63, p. 790. 



It is to be observed that the quicksilver is not affected with the weather, or 

 very rarely, in St. Helena or the Barbadoes; and therefore probably not within 

 the tropics, unless in a violent storm or hurricane. The first is affirmed by Mr. 

 Halley, who kept a glass near two months in the island St. Helena, and the 

 other of Barbadoes stands upon the credit of our registers. 



In England in a violent storm, or when the quicksilver is at the very lowest, 

 it then visibly breaks and emits small particles, which may be considered as a 

 kind of fretting or fermenting : and consequently at all times in its descent, it 

 is more or less on the fret. In this disorder of the quicksilver, I imagine its 

 parts are contracted and brought closer together; which seems probable, for 

 then the quicksilver emits fresh particles of air into the tube, which increasing 

 the bulk of the air, and consequently its elasticity, the quicksilver is necessarily 

 depressed thereby, that is, by an external force or power ; and also the quick- 

 silver must of itself come closer together in its own internal parts, and so de- 

 scend for both reasons. And that much air is mixed with it appears from the 

 application of a heated iron to the tube, as is practised in the purging of it 

 that way ; and also because polished iron will rust when immersed in it, as some 

 philosophers have lately observed. 



Now whenever the quicksilver rises in the tube, which it certainly does both 



