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saccharometer was used instead of the one in use in Jamaica, and that 

 if judged by the latter standard the number of degrees representing 

 the attenuation would be greater. The amount of alcohol obtained is 

 expressed in percentage, i.e., in the number of volumes of absolute al- 

 cohol present in 100 volumes of the wash. The greatest difference in 

 the amount of alcohol produced is between either of yeasts, Nos. 1, 5, and 

 7, and No. 4. Thus on 100 gallons of wash the difference is 1 gallon 

 of absolute alcohol — 10 gallons per 1,000 gallons of wash. Other dif- 

 ferences which are not indicated in the table were also observed among 

 the yeasts. Thus some started fermentation quicker than others, some 

 reproduced themselves more than others ; and some formed a deposit 

 which adhered tightly in a hard pasty mass to the bottom of the fer- 

 menting vessel, while others formed a deposit which was easily disturbed. 

 With the exception of No. 18, and No. 19, which I have not included 

 in the list, the yeasts were all of the " low" fermentation kind, i.e., 

 remained at the bottom of the liquid Nos. 18 and 19 are of the " top" 

 fermentation kind i.e., throw up a "head" on the surface of the liquor 

 during fermentation. With the exception of No. 18 the difference in 

 the flavour of the resulting distillates was not very marked but the 

 quantities operated upon were too small to enable a correct judgment to 

 be formed, and of course the influence of storage in cask had to be left 

 out of account. These results be it observed are results obtained in the 

 Laboratory. If it be asked what results would be obtained by working 

 with such and such a yeast in the Still House ? The answer is that 

 that this can be best determined by direct experiment in the Still 

 House. There is however very little doubt that the comparative dif- 

 ferences shewn here would also obtain in the Still House. No. 18 

 yeast for instance will always be by comparison a much slower ferment- 

 ing yeast than No. 1, and will produce a more aromatic spirit. While 

 No. 4 will be sure to produce more alcohol from a given weight of 

 sugar than Nos, 1, 5 and 7. The object of this paper has been to shew 

 that characteristic differences exist among Jamaica Yeasts which are 

 active in the rum fermentation, that these differences are worthy of study, 

 and may if placed under control be used with great advantage in the Still 

 House. The principle which is advocated here is the selection by syste- 

 matic experiment of that particular type or variety of yeast which is best 

 suited for the kind of work it has to do and the cultivation and propa- 

 gation of it in sufficient quantity for use on a commercial scale i.e., for 

 fermentation in the Still House. If this were not possible our interest 

 in the question would be confined to its scientific aspect, but pure se- 

 lected types of yeast are now in use in large numbers of Breweries and 

 Distilleries. There seems no reason then to doubt that the introduction 

 of selected types of yeast into Distilleries here would also be attended 

 with advantage and in my opinion this forms the basis of a solid im- 

 provement. At any rate this reform seems worthy of a thorough trial 

 on a practical scale, and I append here a description of the apparatus 

 by which the yeast desired may be grown absolutely pure in sufficient 

 quantity for this purpose. I would however strongly advise all those 

 who may take an interest in this subject to purchase " Micro-organisms 

 and Fermentation" by Alfred Jorgensen published by F. W. Lyon, 

 Eastcheap Buildings, London, a short review of which by me appeared 

 in the " Bulletin" for May. Illustrations and descriptions of the two 



