31 



formed in the molasses by certain micro-organisms, previous to fermen- 

 tation (Sell). The organic bases are evil smelling substances of a 

 poisonous nature, but according to my experiments which I shall com- 

 municate at another time, I find they exist in large quantities in the 

 skimmings, and I therefore think that the supposition of Lindet, as to 

 the intervention of micro-organisms in their formation, is not correct. 



The Essential Oil of Rum. 



In the estimation of the higher alcohols, which is based on the ab- 

 sorb tive capacity of chloroform for these substances, Dr. Windisch ob- 

 served both in the case of arrack and rum, that after the chloro- 

 form which had been shaken up with the rum was evaporated off, a 

 small drop of an unsaponifiable terpene kind of oil remained behind, 

 which possessed in a remarkable degree the aroma of rum or arrack as 

 the case might be. Two years ago, while performing some analyses of 

 rum in Germany, I repeated the chloroform experiment and having found 

 the same substance, I extracted several portions of rum in the requisite 

 manner, added the residue to another portion of the same, and sent this 

 sample along with another sample of the same rum, but untreated, to a 

 rum seller in London. The report of the expert on the two samples 

 was, that the sample to which the addition had been made, of which 

 addition it is needless to say he was ignorant, was worth about three- 

 pence a gallon more than the untreated sample of the s^me rum. 



The Fruity Acid. 



Herzfeld in his analysis of rum (Dr. Alex. Herzfeld, Versuche ziir 

 Darstelhmg Rum-artiger Produkte). (The Manufacture of Rum- 

 Products) discovered the existence of an acid of a fruity smell, but the 

 materials at hand were not sufficient to enable him to identify it. Tt is 

 evident that the presence of this acid in greater or less quantity would 

 have a corresponding effect on the quality and therefore on the price of 

 the rum, and I think that I shall presently be able to give some 

 interesting information as to its occurrence. 



With this we conclude the emumeration of the bouquet-producing 

 constituents in rum, which up to now have been discovered by analysis. 

 It seems evident that the points to be aimed at by those desirous of 

 improving the quality of their product, are the production of fruit 

 ethers, the oil of rum, and the fruity acid in the resulting spirit. 



NOTES ON PLANTS YIELDING RUBBER II. 



{Continued from Bulletin for July, 18911). 

 Ceara Rubber. 



Source. — Ceara Rubber is obtained from Manihot Glaziovii, Muell. 

 Arg : a tree 30 to 50 feet high, with 3 to 7 lobed palmate leaves, and 

 potato-like tubers on their roots. 



Locality, Soil and Climate. — Ceara is a town on the sea-coast of 

 Brazil. Mr. Cross went from Ceara 40 miles inland to Pacatuba to 

 obtain plants. The flat country which he passed on his way has, he 

 says, " a very dry arid climate for a considerable part of the year. This 

 is evident from the fact that mandioca [cassava] and other crops require 

 to be irrigated. The rainy season is said to begin in November and 



