526 TRANSACTIONS OF SECTION B. 



hydrochloric acid. The aqueous liquid filtered from the coagulum contains a 

 small quantity of a substance which reduces Fehling's solution only after it has 

 been lieated for a few minutes with hydrochloric acid. Whether this is cane 

 sugar or a glucoside 1 have not yet ascertained. The amount of proteid present 

 is very small. The specific gravity is slightly greater than water. 



The coagulated solid is tough, but contains only a very small quantity of 

 rubber substance, as it is almost entirely soluble in alcohol and acetone. 



Dye.ra ccstulata is reputed to be the botanical source of the white gutta now 

 quite familiar under the name of ' Pontianak,' the name of the port in Borneo 

 from which it is sent to Europe. Pontianak contains a small quantity of rubber 

 mixed with two or more substances, of which at least one (m.p. 173°) is crystal- 

 lisable from alcohol. This, analysed in my laboratory, gave as the mean of several 

 combustions C = 81'2 and H=11'0 per cent. This corresponds roughly to a 

 formula G^^^fi, which requires = 81"5, H = ]07. The molecular weight, 

 206, required for this is, however, much less than the result of observations of 

 the freezing-point of benzene solutions which gave as a mean 322. 



The crystalline substances contained in gutta have been supposed to be related 

 to lupeol, but this can hardly be said to be definitely established. Likiernik ^ 

 found in lupeol C = 84-01, H = 11-38 and melting-point 204°. 



As to the process by which caoutchouc and the associated substances are 

 formed in the latex, nothing seems to be known ; but I incline to the view that 

 they are probably formed in the laticiferous vessels by the rupture of molecules 

 of compounds of the nature of tertiary alcohols with the production of water and 

 the hydrocarbon or other substance. The readiness with which terpin splits into 

 terpineol and water by the action of minute quantities of acid is an analogous 

 process. 



5. The Present Position of the Chemistry of tlie Gtims. 

 By H. H. Robinson, M.A. — See Reports, p. 227. 



On a Gum (Cochlosperinimi Gossypium) vjhich produces Acetic Acid 

 on Exposure to Air. By H. H. Robinson, M.A. 



7. Note on Ergot Alkaloids. By G. Bargeb and F. H. Carr. 



The crystalline alkaloid ergotinine was obtained from ergot by Jauret more 

 than thirty years ago, and does not seem to have been studied chemically since 

 then, no doubt owing to its extreme scarcity. 



Jauret assigned to ergotinine the formula C-oEI.,„Oj2N^, based on rather scanty 

 analytical data ; the molecular weight was deduced by analyses of the amorphous 

 hydrobromide and hydrochloride of very doubtful purity. 



We have been able to confirm Jauret's figures for the percentage of carbon 

 and of hydrogen (roughly = 68-5 per cent., H = 6-5 per cent.), but find nearly 

 3 per cent, more nitrogen (11-7 instead of 9 per cent.).* 



Molecular weight determinations in phenol solution by the cryoscopic method 

 gave the values 477 and 516 ; in pyridine solution the value 463 was obtained, 

 employing a microscopic vapour pressure method, devised by one of us. 



without as yet definitely assigning a formula to ergotinine, we suggest that 

 the alkaloid probably has the composition C27H3,O^N4 = 475. 



It will be seen that the ergotinine molecule is not more complex than that of 

 several well-known alkaloids, and that it is much smaller than Jauret imagined. 

 It is unique among alkaloids in containing four nitrogen atoms. 



' Ber. 24, 185. 



* We used Dumas' method ; Jauret worked according to Will and Varentrapp. 

 We are indebted to Dr. P. Haas for two of the determinations, in which he proved 

 the absence of methane in the residual nitrogen gfvs. 



