200 APPENDIX 



their action iu the fermentation of sugar. Three of the plants 

 curiously enough belong to the natural order Oleacese ; these are Olea 

 glanduliferaj jasmintim and ligustrum, and like other plants of this 

 order contain a peculiar bitter principle, soluble in water and alcohol, 

 and a yellow colouring matter called quercetin. Two other bai'ks of 

 the series belong to the same natural family of the laurels, and have a 

 similar composition ; these are the Litsseas. The Hiptage bark con- 

 tains tannin, and is simply an astringent; and the Gmelina belongs 

 to a class of plants distinguished for their bitterness. 



The amount of extract dissolved out of the bark by water and 

 alcohol respectively were determined in order to ascertain their 

 relative proportion, as it would seem that in the absence of much 



resin, the excess of water extract over the spirit extract would 



* 



indicate mucilaginous matter, and on the barks being placed in the 



toddy, which in afresh state is a watery solution of sugar, with some 

 albuminous matter, the extract would dissolve, but as fermentation 

 proceeded, alcohol would be formed and the mucilage would become 

 insoluble and precipitate, carrying down with it the viscid albumen, 

 and thus allow the sugar to ferment more rapidly. From the fact 

 that other gum -barks besides the Litsseas, such as Kydia calycinci 

 and Gnaziima tomentosa, arc largely used in clarifying sugar, it is 

 evident that some such object as this is intended in their employment. 

 The astringent qualities of most of the above-mentioned barks are no 

 doubt used for the purpose of forming insoluble compounds with 

 albuminous matter in saccharine solutions; just as hops are used to 

 remove this substance from malt liquor in the ordinary process of 

 brewing beer. The hops are found to prevent in a great measure 

 the tendency of the beer to become sour, in consequence of the 

 conversion of alcohol into acetic acid, and in warm climates wbere 

 such liquors are apt to run into the acetous fermentation very 

 rapidly, it is necessary to employ astringent drugs to regulate the 

 formation of alcohol and prevent the development of acetic acid. 



The natives consider these barks a necessary ingredient in making 

 spirit, for the following reasons : Firstly, they diminish the great 

 sweetness of the toddy sugar. Secondly, they render the spirit more 

 intoxicating. The first of these phenomena is accounted for by the 

 chemical fact that sugar breaks up during fermentation into two 

 other bodies, alcohol and carbonic acid ; and in the second place the 

 barks enable the operator to obtain a larger proportion of alcohol from 



