APPENDIX. 329 



(c.) Fibriiioplastin or fibrinoplastic globulin or paraglobulin is pre- 

 pared from blood-serum diluted with 10 vols. of water, by passing a cur- 

 rent of carbonic acid gas, and collecting the fine precipitate which is 

 formed, and washing with water containing carbonic acid gas. The 

 current should be strong and not long continued. It may be better pre- 

 pared as a sticky white substance, by saturating serum with crystallized 

 sodium chloride or magnesium sulphate. (See also p. 69, Vol. I.) It 

 coagulates at 68 80 C. 



(d.) Fibrinogen is prepared from hydrocele and other like fluids by 

 diluting and passing a brisk current of carbonic acid gas (COJ through 

 the solution; or by saturation of the nerve fluids with sodium chloride or 

 magnesium sulphate. (See also p. 69, Vol. I.) It coagulates at 55 

 57 C. 



(e. ) Vitellin can be prepared from yelk of egg, in which it is prob- 

 ably associated with lecithin. 



IV. Fibrin is a white filamentous body formed in the spontaneous 

 coagulation of certain animal fluids. It is insoluble in water, except at 

 very high temperatures, soluble in dilute acids and alkalies to a slight 

 degree, and in strong neutral saline solutions. Soluble also in strong 

 acids and alkalies. 



It is prepared by washing blood-clot or by whipping blood with a 

 bundle of twigs. Its formation in the blood has been already fully con- 

 sidered. 



V. Peptones (or albuminose) are nitrogenous bodies of uncertain 

 composition made in the process of the digestion of other proteids. It is 

 almost certain that there are several distinct forms. 



The great distinction which exists between peptone and other proteids 

 is their diffusibility and they giving no precipitates with either acids or 

 alkalies, with copper sulphate, ferric chloride, potassium ferrocyanide 

 and acetic acid, or on boiling, and only with picric acid, tannin, mer- 

 curic chloride, silver nitrate, and lead acetate. In addition to this the 

 color which a peptone gives with potassium hydrate and cupric sulphate 

 is reddish instead of violet. 



Kuhne believes that ordinary albumin splits up under the action of 

 the gastric juice or pancreatic juice into two parts, one called antialbu- 

 mose, and the other h em ialbumose, and further that antialbumose becomes 

 antipeptone and heimalbumose, hemipeptone. The difference between 

 hemipeptone and antipeptone is that the former can be further split up 

 by the action of the pancreatic juice. He believes that antialbumose is 

 closely allied to syntonin, and that the hemialbumose is more like myosin, 

 and if the pepsin be feebly acting, a body which he calls antialbuinate 

 appears, which cannot be converted into peptone by gastric juice, but can 

 by pancreatic juice. Solutions of hydrochloric acid or of sulphuric acid 

 can, under favorable circumstances, partially change albumin into peptone. 



VI. Coagulated Proteids. When a native albumin or a globulin 

 is raised to a certain temperature (varying a little with each substance), 



