Mr. J. N. Furze on Fermentation. 313 



me, there was not any product, after passing the gaseous 

 matter through a worm three quarters of an inch diameter 

 and 35 feet in length, surrounded with water at a temperature 

 of 54-° for a period of 36 hours on each occasion. 



Having arranged the improved tun as before described, the 

 gas arising from six fermentations was allowed to escape 

 through the water in the external vessel. After the gas had 

 thus been washed it had lost much of the pungency of smell 

 so characteristic of the usual mode of escape, and in a few 

 days the water had so far changed, that it had a strong foetid 

 odour, similar to that of waste starch liquors, and certainly 

 not that of the aroma of the hop. This, from the great dif- 

 ference between the water in question and that of the same 

 bulk which had not been so treated, must have resulted from 

 the absorption of a something passing off in mechanical sus- 

 pension with the gas. In order to ascertain the contents of the 

 water after being charged with the gas and vapour, some of 

 it was distilled, immediately after the transmission of the gas, 

 and the result was, that from 36 gallons of the water so em- 

 ployed, 9 pints of alcohol were obtained of specific gravity 

 0*850. Jt appeared, on further prosecuting the matter, that 

 more could have been obtained had a larger quantity of water 

 been used, and that the action of the water on the gas de- 

 pended for its efficacy, in a great degree, upon the apparatus 

 itself. In endeavouring to realize more extended results a 

 tub was made, which contained an arrangement of three tin 

 plates perforated with holes, set one inch apart from each 

 other, through which the gas passed in small bubbles, by 

 which means the washing of the gas was rendered more ef- 

 fectual. In this manner 3 per cent, of rough spirit was fre- 

 quently obtained, of specific gravity 0*850, by distillation from 

 the gas produced by one fermentation. All these distilled 

 products were impregnated with ammonia to a considerable 

 amount, which would necessarily affect these results, as is 

 shown by the following experiments. 



45 gallons of water having received a charge of gas from 

 the fermentation of 350 barrels of porter wort had a specific 

 gravity 0*9988, and the attenuation of the worts during the 

 period was about 12 lbs. per barrel, as indicated by the sac- 

 charometer of Dring and Fage. Of this quantity 36 gallons 

 were reduced to one-sixth part by distillation, of which 16 oz. 

 by measure were again carefully rectified and reduced to 4 oz., 

 which had a specific gravity 0*965, being equal to 33 percent, 

 of alcohol at 0*825. It therefore follows that the 45 gallons 

 would have yielded 15 imperial pints at 0*965, which would 

 equal 5 pints at 0*825, or about 1*4 per cent, of alcohol by 

 volume. 



