OF THE BLOOD. 227 



yellow serum or colourless lymph ; T but it does not ; on the 

 contrary, it is coloured red by these particles, even when used 

 in much greater proportion than thirty-six parts of water to 

 one of blood. 



These red vesicles of the blood have not only been commonly 

 supposed globular and fluid, but they have with equal injustice 

 been imagined to be oily, and more inflammable than the rest 

 of the blood (cvm). That they are not oily, is evident from 

 their so readily dissolving in water, and that they are not more 

 inflammable than the rest of the blood is manifest, by burning 

 them after they are separated from the rest of the blood ; which 

 separation may be effected by shaking the crassamentum in 

 the serum, so as to diffuse the particles through it, and then 

 by pouring off the serum when they have subsided in it. I have 

 separated them in this manner, and compared their inflamma- 

 bility with that of inspissated serum, and of dried coagulable 

 lymph, and have not observed them more inflammable than the 

 serum or the lymph ; nor do they melt like oil, as some have 

 suspected, but burn like a piece of horn. Some authors who 

 have written on the figure of these vesicles in quadrupeds and 

 in the human subject, have expatiated on the great advantage 

 of their (supposed) spherical shape, in order for their more easy 

 circulation ; as it is probable that no form is preferable to a 

 spherical one for easy motion ; but as these vesicles are evidently 

 not spherical, but flat in all animals, we must believe that 

 nature has some good purpose to answer by making them of 

 that form. 



It has been objected that, notwithstanding they appear flat 

 out of the body, they may possibly be globular in the body 

 while circulating ; and it has been said, that it is almost in- 

 conceivable that so many ingenious men should at different 



1 See Gaubii Pathologia. 



(cvm.) Senac and Haller, referred to in Note xcix, regarded them 

 as solid ; and Haller refuted the opinion of their discoverer, Malpighi, 

 that they are particles of oil ; but Senac a described them as formed of 

 sulphurous matter, burning and putrefying more quickly, and giving 

 out more volatile oil, than the rest of the blood. Gaubius b considered 

 them as oily globules, like those of milk. 



a Traite du Coeur, torn, ii, p. 81, ed. 1749 ; b Institutions Pathologiae Medicinalis, 

 and torn, ii, p. 275, 2d ed. 280, 347, 8vo, Leid. Batav. 1758. 



