14 ORGANISED FLUIDS. 



water ; in mammalia and most vertebrate animals, being of a 

 red colour, but colourless in the invertebrata * ; circulating in 

 distinct sets of vessels, arteries, and veins ; holding in solu- 

 tion, all the elements of the animal fabric fibrin, albumen, 

 and serum, together with various salts and bases, and in 

 suspension, myriads of solid particles termed globules, f 



The blood would thus appear to be the grand supporter 

 and regenerator of the system ; in early life, supplying the 

 materials necessary for the development of the frame, and, 

 in adult existence, furnishing those required for its main- 

 tenance: hence "the blood" has been figuratively called 

 " the life." 



COAGULATION OF THE BLOOD, WITHOUT THE BODY. 



The first change which the blood undergoes subsequent to 

 its removal from the body consists in its coagulation. This 

 phenomenon has been denominated emphatically " the death 

 of the blood," because, when it has once occurred, the blood 

 is thereby rendered unfit to maintain the vital functions, 

 and there is no known power which can restore to it that 

 faculty. 



Although the word coagulation is usually applied generally 

 to the blood, yet it is not to be understood that the whole of 

 the mass of that fluid undergoes the change of condition 

 implied by the term coagulation, which affects but a single 

 element of the blood, viz. the fibrin. 



The precise circumstances to which the coagulation of the 



* Miiller states that the quantity of blood in the system varies from eight 

 to thirty pounds, and Valentin found that the mean quantity of blood 

 in the male adult, at the time when the weight of the body is greatest, 

 viz. at thirty years, is about thirty-four and a half pounds, and in the 

 adult female, at fifty years, when the weight of the body in that sex is at 

 its maximum, about twenty-six pounds. According also to Miiller, the 

 specific gravity of the blood varies from P527 to 1'057 ; arterial blood is 

 lighter than venous. 



f In one vertebrate animal, a fish, Branchiostoma lubricum Costa, the 

 blood is colourless, and in the most of Annelida it is red ; the red colour, 

 however, exists in the liquor sanguinis, and not in the blood corpuscles. 



