222 FUNCTIONS OF NUTRITION. 







Cry stall izable nitrogenous matters .... 4.00 



Other organic ingredients ...... 5.00 



Sodium chloride 



Potassium chloride 



Sodium carbonate [ Mineral salts 



Sodium and potassium sulphates 



Sodium and potassium phosphates 



Lime and magnesium phosphates J 



1000.00 



Of these substances, albumen no doubt holds the first place in regard 

 to nutrition, as it presents, in a high degree, the character of a nutritious 

 material. It, in all probability, supplies the greater part of the nitro- 

 genous ingredients of the tissues, and provides for their daily nourish- 

 ment and renovation. In this process it must suffer a variety of trans- 

 formations, by which it is converted into the different albumenoid mat- 

 ters characteristic of muscular, nervous, glandular, and other structures 

 throughout the body. 



The ingredient next in abundance is paraglobuline, the average quan- 

 tity of which is about one-half that of the albumen. It is closely allied 

 to albumen in its chemical relations, and no doubt also in its physiolog- 

 ical action ; and it is possible that cither one of these substances may 

 be an intermediate stage of production or metamorphosis of the other. 

 The principal distinction between them is that paraglobuline may be 

 thrown down by the addition of sodium chloride in excess, or by passing 

 through the diluted blood-serum a stream of carbonic acid, neither of 

 which agents has any effect on albumen. As both substances are coag- 

 ulable by heat, they are solidified together on raising the blood-serum to 

 a temperature of 72 C. 



The fibrinogen of the plasma is the substance which produces the 

 solid fibrine of coagulated blood. It is difficult to obtain in the fluid 

 condition, owing to the rapidity with which it coagulates when blood 

 is withdrawn from the circulation. It is usually separated, in the form 

 of coagulated fibrine, by stirring freshly-drawn blood with glass rods or 

 a bundle of twigs, when the fibrine solidifies in thin layers on their 

 surface. It at first contains, entangled with it, some of the red glob- 

 ules with their coloring matter ; but these and other foreign substances 

 may be removed by immersing it for a few hours in running water. 

 , It is then a mass of nearly white threads and flakes, of semi-solid con- 

 sistency, and having a considerable degree of elasticity. 



Examined in thin layers, it has a fibroid or filamentous texture. Its 

 filaments are colorless and elastic, and not more than 0.5 mmm. in diam- 

 eter. They lie, for the most part, parallel with each other, and this is 

 probably their arrangement throughout in the undisturbed fibrinous 

 layer ; but when torn up for microscopic examination, they are in 

 many spots interlaced with each other in an irregular network. In 

 dilute acetic acid they become swollen, transparent, and fused into a 

 homogeneous mass, but do not dissolve. They are often interspersed 



