5 14 Kirwanian Society of Dublhu 



that the whole of the water could not be removed. Th(5 

 author then stated objections which arise when certain 

 other methods are employed, the consideration of which 

 occasioned in him a distrust of his estimate of the vegetable 

 soluble matter. 



The general method employed was to dry a certain quan« 

 tity of the grass, to digest it in water, and dry the residuum 

 in the same temperature as at first: the weight lost in these 

 processes showed the quantity dissolved, and this quantity 

 generally agreed pretty exactly with the solid extract obtained 

 by evaporating the filtered water. In this manner, with but 

 little variation, 25 per cent, of extract, that is, of soluble 

 nutritious matter, was obtained. 



It was then stated that the author after many attempts 

 %!!i% not enabled to obtain sugar in the insulated form; but 

 tbat by a complicated process he separated what is most pro- 

 bably saccharine matter of a peculiar nature, amounting to 

 10 per cent. : this result was corroborated by the action of 

 alcohol on the extract. 



But whether the saccharine matter exist in the grass as 

 sugar or as a peculiar substance, it is certain that alcohol is 

 producible from it in no very inconsiderable quantity. It was 

 stated that different persons who conducted the process for 

 the author produced different quantities. On one trial made 

 with more accuracy than the rest, and under the author's 

 immediate inspection, twenty-six ounces and a half of spirit 

 (S. G. 930) were obtained from 27i avoirdupois pounds of 

 the grass, which did not amount to one half of what was 

 produced when large but proportionate quantities had been 

 employed, and in the hands of experienced distillers. 



The formation of 26-i- ounces of spirit certainly does not 

 at first sight seem to countenance the quantity of saccharine 

 matter as above stated. Had there been 10 per cent, present, 

 the whole quantity in 27|r pounds must be 19,200 grains: 

 these, according to Thenard's experiments, would produce 

 9,856 grains of alcohol (S. G. 791), whereas but 4,580 were 

 really obtained. The latter quantity would indicate the exist- 

 ence of no more than 4^- (nearly) per cent, of saccharine 

 matter. But this offers no sufficient objection; it rather 

 offers a presumption in favour of the abovementioned sug- 

 gestion, namely, that the sugar does not exist in an insu- 

 lated form, but in such a combination perhaps as to consti" 

 tute a peculiar proximate principle. 



JMPERIAI. 



