404 SIEGFRIED'S RESEARCHES ON RETICULIN. [BOOK n. 



Preparation When purified reticular tissue is boiled with water 



of reticuiin. or gQ m i nu tes, or even only for 15 minutes, it loses its 

 structure and becomes converted into a light powdery body. If the 

 liquid be filtered and the clear filtrate concentrated and then cooled 

 it gelatinises. The solution answers to all the tests for gelatin, of 

 which the quantity formed is, however, very small. 



The powdery body above referred to, having been repeatedly 

 boiled with water, is thoroughly washed, first with water, afterwards 

 with alcohol, lastly with ether; it is then dried, either at 110 C. or 

 at the temperature of the air over sulphuric acid. 



Physical and Reticulin is insoluble in water, alcohol, ether, con- 

 chemical pro- centrated salt-solutions, lime water, solution of sodium 

 perties of reti- car b ona te, and dilute mineral acids. Dilute solution of 

 caustic soda at ordinary temperatures requires weeks 

 to dissolve it. Reticulin gives the biuret and the xanthoproteic 

 reaction, but not Millon's reaction ; though it is difficult to obtain a 

 preparation so pure that when treated with Millon's reagent it does 

 not assume a feeble red colour. When only once digested with 

 pancreatin, it always shews this reaction ; hence the reason for twice 

 repeating the process, as directed previously. When reticuiin is 

 boiled with glacial acetic acid, it partly dissolves and the solution 

 exhibits Adamkiewicz's reaction. 



Reticulin is an organic compound containing carbon, hydrogen, 

 nitrogen, sulphur, phosphorus and oxygen; it cannot be obtained 

 free from ash. The latter contains sodium, but no potassium, small 

 quantities of calcium and magnesium, phosphoric acid, chlorine and 

 sulphuric acid. 



The following exhibits the mean of the analyses made by 

 Siegfried : 



Carbon 52'88 



Hydrogen 6 '9 7 



Nitrogen 15'63 



Sulphur , 1-88 



Phosphorus 0'34 



Mineral matters 2*27 



Reticulin is, as will be seen from the above data, characterised 

 by a high percentage of sulphur. When heated, even for many days, 

 with water at a temperature of 140, it gives off no sulphuretted 

 hydrogen. The sulphur is, however, in part at least, separated when 

 reticuiin is boiled with strong solution of caustic soda or with strong 

 hydrochloric acid. 



The phosphorus, which reticuiin contains, is in organic combination, 

 as proved by the following fact. When 1 gramme of reticuiin is 

 digested with constant shaking at a temperature of 25 C. with dilute 

 nitric acid (containing 41 / of NO 2 . OH), the solution, when tested 

 with ammonium molybdate, is found to contain no phosphoric acid, 



