CHAPTEE II. 



COMPOSITION OE THE BLOOD. 



General considerations Methods of quantitative analysis Fibrin Corpuscles 

 Albumen Inorganic constituents Sugar Fatty emulsion Coloring matter 

 of the serum Urea and the Urates Cholesterine Creatine Creatinine. 



ASSUMING, as we certainly must, that the blood furnishes 

 material for the nourishment of all the tissues and organs, we 

 expect to find entering into its composition all the proximate 

 principles existing in the body which undergo no change in 

 nutrition, like the inorganic principles, and organic matters 

 which are capable of being converted into the organic ele- 

 ments of every tissue. Furthermore, as the products of waste 

 are all taken up by the blood before their final elimination, 

 these also should enter into its composition. With these 

 great principles in our minds, it is unnecessary to insist upon 

 the importance of accurate proximate analyses of the circu- 

 lating fluid. It is not many years that our knowledge of 

 the laws of nutrition and destructive assimilation have enabled 

 us to appreciate the full importance of the blood ; but it has 

 been so palpable that this fluid is necessary to life, that the 

 older physiologists made numberless futile attempts to obtain 

 some clear idea of its composition. We have only to go 

 back to the beginning of the present century to find the first 

 analyses of the blood which were attended with any degree 

 of success. In 1808, Berzelius analyzed the serum of the 



