34 



Mr. J. R. Green. 



[Jail. 14, 



galactodendion, Don), one of the Artocarpeoe. They describe it as 

 containing, among other constituents, a fibrous matter of animal 

 nature, which was obtained by evaporating the latex down to dryness, 

 washing the residue with essential oils to free it from waxy and 

 resinous matters, and then getting rid of the essential oils by pressing 

 dry and boiling with water. This treatment left them a brown mass 

 which contained nitrogen. On heating this on hot iron they say it 

 burned, giving off an odour similar to that coming from meat heated 

 in the same way. This matter was not soluble in alcohol, and when 

 obtained by repeated extraction with hot spirit, was left as a residue 

 composed of white flexible threads. Thinking it possessed all the 

 characteristics of animal fibrin they gave it the same name. 



Since the date of their paper no information has been forthcoming 

 as to the real nature of this vegetable fibrin. A quantity of the 

 latex was obtained by Dr. Vines from Dr. Ernst of Caracas, and a 

 bottle of it was, by his kindness, made available for the purposes of 

 this investigation. The fluid had been mixed with a small amount of 

 alcohol with a view to its preservation during its transit to England, 

 and the treatment had been not quite so successful as that oE the East 

 Indian latex, some, but not much, of the proteid having been 

 coagulated by the spirit. Still the fluid was of thick creamy con- 

 sistency, and on digestion with water, and subsequent filtration, 

 yielded a strongly proteid solution.* Extracts were made with water 

 and with solutions of neutral salts, but the resulting liquid behaved in 

 the same manner by whichever method it was prepared. 



This extract contained two proteids, one of which was of the nature 

 of an albumin. When the solution made with distilled water was 

 examined, it was found to contain no salts capable of holding a 

 globulin in solution, the only ones present being a mere trace of 

 phosphates. The solution, on being dialysed till free from salts 

 altogether, did not deposit any precipitate. On being boiled there 

 was a well-marked coagulum, and after filtration the now coagulated 

 matter gave a strongly marked xanthoproteic reaction. When the 

 solution was gradually heated in the usual apparatus! the coagula- 

 tion of the proteid took place at 68° C. The other tests for a proteid 

 were fairly satisfactory, but were applied with more difficulty than 

 with an animal albumin. With Millon's reagent there was a white 

 precipitate, which went brick-red on boiling ; with copper sulphate 

 and sodic hydrate the violet colour was obtained, but not unless the 

 soda solution was very strong. There was, however, no precipitate 

 with acetic acid and potassic f errocyanide. 



* The results of my examination of this latex, and a summary of the properties 

 of the bodies found in this and other vegetable fluids described later, were commu- 

 nicated to the Physiological Society at its Cambridge meeting, May 9, 1885. 



f Gamgee's " Physiological Chemistry," p. 15. 



