30 



Mr. J. R. Green. 



[Jan. 14, 



quantities of caoutchouc, resinous matters, &c, the latter being very 

 variable in amount, and absent from some samples. The material was 

 collected in the Malay Peninsula from the plants, and a little alcohol 

 having been added as a preservative, was sent to England in sealed 

 bottles. On its arrival at the laboratory, some of the bottles had 

 their contents hardly at all changed except that the large amount of 

 caoutchouc contained in the fluid had undergone the process techni- 

 cally known as coagulation, and was floating in a milky liquid. 

 Others had become quite spoiled in transit, the latex having deposited 

 a quantity of amorphous matter, which gave a xanthoproteic reac- 

 tion, and seemed to be coagulated proteid. In the debris besides 

 this, there appeared under the microscope, a number of small droplets 

 of caoutchouc, a few sphsero- crystals, some spicular crystals, and some 

 flat plates of rhomboidal form. 



Examination of these last as to proteids not being practicable, 

 attention was given to the uninjured samples, which differed in no 

 way from each other. The particular experiments, whose results are 

 detailed below, were made upon the latex of a plant, the Malay name 

 of which was given as " Gegrip puteh."* 



The mass of caoutchouc floating in the fluid was allowed to drain 

 dry, and was then with difficulty cut up into small pieces and mace- 

 rated some in water and some in salt solutions. Soaking for several 

 days failed to extract anything of a proteid nature from it. Atten- 

 tion, therefore, was directed to the liquid remaining after its separa- 

 tion. This, as said above, was milky in appearance, of a faintly 

 yellow colour, aromatic smell,[and neutral reaction. Under the micro- 

 scope it was at once apparent that the milky appearance was due to 

 minute droplets of caoutchouc which had not separated out with the 

 bulk. There was nothing granular or amorphous visible, showing 

 that the proteids had not been precipitated by the alcohol used. To 

 free the latex from the caoutchouc, filtration under vacuum pressure 

 through a porous pot was necessary, when the droplets formed a film 

 round the earthenware, and as the liquid was gradually removed they 

 fused together, giving rise to a thin sheet of india-rubber. The fluid 

 passed through the pot clear and in a condition fit for examination. 



In this liquid so prepared a very curious proteid body was found 

 to exist, differing in important particulars from any hitherto described 

 as occurring in plants. f Its presence was readily shown by the 



* [Yielded by an Apocynaceous plant, Parameria glandulifera. The selection of 

 this particular sample, which happened to stand first in a series of thirty-four, was a 

 little unfortunate, as it is not a very characteristic caoutchouc-yielding species. — 

 W. T. T. IX] 



f In a communication made to the Camhridge Philosophical Society I have 

 already given a brief account of its properties and reactions (" Proc. Camb. Phil. 

 Soc," vol. v, Part III, p. 183, October term, 1884). 



