THE CHEMICAL COMPOSITION OF THE BODY. 



boiling; it may give a blue color with ozonic ether and tincture of 

 guaiacum. 



Pamglobulin. Paraglobuliii is contained in plasma and in serum, in 

 serous and synovial fluids, and may be precipitated by saturating plasma 

 after removal of fibrinogen or serum with solid sodium chloride or magne- 

 sium sulphate, as a bulky flocculent substance which can be removed by 

 filtration. 



It may also be prepared by diluting blood serum with ten volumes of 

 water, and passing carbonic acid gas rapidly through it. The fine pre- 

 cipitate may be collected on a filter, and washed with water containing 

 carbonic acid gas. 



It is very soluble in dilute saline solutions (5 to 8 per cent), from, 

 which it is precipitated by carbonic acid gas or by dilute acids ; its solu- 

 tion is coagulated at 70 C. ; even dilute acids and alkalies convert it 

 into acid- or alkali-albumin. 



Fibrinogen. Fibrinogen is contained in blood-plasma, from which it 

 may be prepared by addition of sodium chloride to the extent of 13 per 

 cent. It may also be prepared from hydrocele fluid or from other serous 

 transudatioii by a similar method. 



Its general reactions are similar to those of paraglobulin ; its solution 

 is coagulated at 52-55 C. Its characteristic property is that, under 

 certain conditions, it forms fibrin. 



JEdestrine. Edestrine is a globulin which is found in many edible 

 vegetables, grain, etc. A solution may be prepared by adding hemp seed 

 to a 10 per cent solution of sodium chloride and heating to 50 C. 



Proteoses are intermediate substances of the digestion of other pro- 

 teids, the ultimate product of which is peptone. They are produced by 

 the action of the gastric and pancreatic juices and also, slowly, by boiling 

 with dilute acids. The term is a general one, the proteose of albumin 

 being albumose, that of globulin being globulose, etc. They are divided 

 into primary and secondary groups representing the stages of progression 

 from, proteids to peptones, so that there may be a primary and a second- 

 ary albumose, etc. As digestion is a process of hydration with cleavage, 

 the successive stages present progressively simpler substances. Each 

 group reacts to fewer reagents than the preceding one; e.g., none of the 

 proteoses can be coagulated by boiling, nitric acid will precipitate the 

 primary proteoses but not the secondary ones. 



Peptones. Peptone is formed by the action of the digestive fer- 

 ments, pepsin, or trypsin, on other proteids, and on gelatin. It is a still 

 simpler form of substance than the proteoses and reacts to still fewer re- 

 agents. They will be considered in connection with the physiology of 

 digestion, as will also the intermediate compounds. 



Coagulated proteids are formed by the action of heat or of ferments 



