82 THE CHEMICAL COMPOSITION OF THE BODY 



powdered glass, extracting with dilute saline solution, and by passing through 

 the extract a stream of carbon dioxide. It differs from other globulins in 

 not being precipitated by saturation with sodium chloride. 



The globulin, myosin, may be prepared from muscle by removing all 

 fat, tendon, etc., and washing repeatedly in water until the washing con- 

 tains no trace of proteids, mincing it, and then treating with 10 per cent solu- 

 tion of sodium chloride, or similar solution of ammonium chloride or magne- 

 sium sulphate. The salt solution will dissolve a large portion into a viscid 

 fluid, which filters with difficulty. If the viscid filtrate be dropped little by 

 little into a large quantity of distilled water, a white flocculent precipitate 

 of myosin will occur. 



Myosin is soluble in 10 per cent saline solution; it is coagulated at 60 C. 

 into coagulated prcteid; it is soluble without change in very dilute acids; 

 it is precipitated by picric acid, the precipitate being redissolved on boiling; 

 it may give a blue color with ozonic ether and tincture of guaiacum. 



Serum globulin is contained in plasma and in serum, in serous and syno- 

 vial fluids, and may be precipitated by saturating plasma after removal of 

 fibrinogen, or by saturating serum with solid sodium chloride or magne- 

 sium sulphate. Globulin separates 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 precipitate 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 solution is coagulated at 72 C. Dilute acids and 

 alkalies convert it into acid or alkali albumin. 



Fibrinogen is contained in blood plasma, from which it may be prepared 

 by the addition of sodium chloride to the extent of 13 per cent. It may 

 also be prepared from hydrocele fluid or from other serous transudation by 

 a similar method. Its general reactions are similar to those of paraglobulin. 

 But its solution is coagulated at 55-56 C. Its characteristic property 

 consists in the facility with which it forms the insoluble proteid fibrin. 



Edestin is a globulin which is found in many edible vegetables, grain, 

 etc. A solution may be prepared by adding hempseed to a 10 per cent 

 solution of sodium chloride and heating to 50 C. 



Albuminates. There are two principal substances belonging to 

 this class: a, acid albumin; b, alkali albumin. 



Acid Albumin. Acid albumin is made by adding small quantities of 

 dilute acid (of which the best is hydrochloric, 0.4 to i per cent) to either 

 egg or serum albumin diluted with five to ten times its bulk of water, and 

 keeping the solution at a temperature not higher than 50 C. for not less than 

 half an hour. It may also be made by dissolving coagulated native albumin 

 in strong acid, or by dissolving any of the globulins in acids. Solid acid 



