THE BLOOD. 155 



much, but averages about 4 per cent, of the ash; the phosphate of 

 soda about 8 per cent. ; while the sulphate of potassa depends mostly 

 on the manner of incineration. The salts together average about 

 .85 per cent, of the serum. They are more abundant in the blood of 

 men and of adults than in that of women and children. There are 

 more salts in arterial than in venous blood, except that of the portal 

 blood, which contains more than that of the arteries. In case of 

 repeated bleedings, more salts are found in the blood last drawn 

 than in the first. The serum salts are much diminished in violent 

 inflammations, and still more so in cholera ; while they are consi- 

 derably increased in acute exanthemata, typhus, dysentery, Bright's 

 disease, and especially in dropsy. 



The carbonate of ammonia is found in the blood only in severe 

 diseases, and especially in ursemia; and almost always in the blood 

 of cholera patients. 



Origin. The liquor sanguinis is derived from the lymph and the 

 chyle, principally from the latter. 



The sources from which its mineral constituents are originally 

 derived have been specified in connection with each of the imme- 

 diate principles, in the first part of this work. The fats are almost 

 entirely taken in the food. The albumen is derived directly from 

 albuminose ; the latter being formed in the small intestine, as has 

 been shown (p. 87), from the digestion of the albuminous sub- 

 stances (albumen, caseine, and fibrine) and the peculiar organized 

 immediate principles (osteine, musculine, elasticine, &c.) of the food. 

 The fibrine is also formed at once from the albuminose, or from the 

 albumen in the blood. 



Uses. From the liquor sanguinis all the tissues and the fluids, 

 except chyle, are formed, unless the blood-corpuscles also have 

 some part in the development of the former ; which will be shown 

 to be improbable when the functions of the corpuscles are discussed. 



Nor is it difficult to decide what is the precise function of each 

 of the elements of the liquor sanguinis, excepting the albumen and 

 the fibrine. The water is indispensable, both as a solvent of, and 

 as a vehicle for carrying, the blood constituents to the capillaries; 

 and it also enters into the composition of all the solids and fluids 

 of the body (p. 45). The salts are essential constituents of the 

 tissues and the fluids, and the use of each is specified in the first 

 part of this work. E. g. common salt aids in the assimilation and 

 the dis-assimilation of the tissues, and prevents the solution of the 



