194 PHYSIOLOGY. 



ceeds, the mass contracts into a smaller bulk, and, in propor- 

 tion, becomes more dense. 



CCXLIX. This is the separation which almost always 

 takes place, and has, at all times, been observed by physicians. 

 The fluid part is called serum, and the thicker consistent part 

 has been called cruor, but more properly the crassamentum. 



CCL. Both parts seem homogeneous and simple, but are not. 

 For, if the crassamentum taken from the serum be laid upon a 

 linen cloth, and water is poured upon it, the water washes off a 

 red coloured part, and carries it through the pores of the cloth, 

 and there remains a whitish, consistent, but soft and tough 

 mass, not to be further diminished or separated into parts by 

 any ablution. 



A like experiment shows always a like matter present in the 

 mass of blood; and, upon several occasions, both while the 

 blood remains within the vessels, whether of the living or dead 

 body, and when it is drawn out .of the vessels of the living, this 

 matter spontaneously separates from the other parts of the 

 blood. It is therefore a part constantly present in the blood. 

 It is what Gaubius, after Malpighi, calls the Jibra sanguinis. 

 Mr. Senac names it the coagulable lymph, and we shall speak 

 of it under the title of the gluten of the blood. When it ap- 

 pears upon the surface of the blood drawn out of the vessels of 

 the living animals, it is called the inflammatory crust. 



CCLI. When the blood is viewed with a microscope, whe- 

 ther as moving in the vessels of a living animal, or when out of 

 the vessels remaining still fluid, there are certain parts of it 

 which appear of a round figure, and also of a red colour, while 

 the rest is almost colourless. The parts thus distinguishable 

 by their figure, are called the red globules; audit appears, that 

 the red colour of the whole mass depends upon the presence of 

 these only. It is chiefly these parts which are washed off from 

 the crassamentum in the experiment above-mentioned ; and we 

 now conclude that, besides the red globules, the gluten, and a 

 portion of serum that happens to be entangled in the pores of 

 the concreting mass, there is no other matter evident in the 

 crassamentum. 



CCLII. The serum is a transparent fluid of very little co- 

 lour, and seemingly simple ; but if it be exposed to a heat of 



