PHYSIOLOGY OF THE INVERTEBRATA. ni 



The process consists in hardening the organ in alcohol for 

 three days, and then cutting it up into very small pieces, e!x- 

 tracting with glycerol and filtering. 



On the addition of alcohol to the filtrate, the ferment is 

 precipitated. 



The action of this ferment or ferments on starch Was the 

 complete conversion of the latter into dextrose or right- 

 handed glucose, which was proved by the action of Fehling's 

 solution ; and the formation of crystals (CsHijOe NaCl, H^O) 

 ' with a solution of sodium chloride, a distinction from 

 levulose or left-handed glucose, which does not form these 

 crystals with sodium chloride solution. The action of the 

 ferment on fibrin was the formation of leucin (a- amido- 

 caproic acid, CeHjjNOj) and tyrosin (paraoxyphenylamido- 

 propionic acid, GjHuNOa); for on treating the fermented 

 mass with hot water and filtering, a solution is obtained 

 which contains leucin and tyrosin. When acetic acid was 

 added to this solution, acicular crystals were deposited. 

 These crystals are insoluble in ether, but soluble in boiling 

 water. The aqueous solution produced a red flocculent pre- 

 cipitate on the addition of a neutral solution of mercuric 

 nitrate ; this reaction is characteristic of tyrosin. 



The acetic acid solution, after precipitating the tyrosin, 

 was evaporated, when leucin was deposited in white shining 

 plates, which melt at 98° C. These crystals of leucin were 

 heated with barium oxide, the result of the action being the 

 formation of amylamine and carbon dioxide : — 

 OeH,3NO, = N(G,H,)H, + CO, 



By digesting the organ itself with boiling water and 

 filtering, the filtrate contained leucin and tyrosin. The 

 ferment has no action on cellulose. 



Prom these investigations, the so-called liver of Seipia 

 officinalis is proved to be a pancreas, for the juices of the organ 

 are purely digestive in function, digesting starch, oil, and 

 similar bodies, and transforming fibrin into leucin and tyrosin. 

 Then, again, albumin is present in its secretion, which is 



