TECHNOLOGY. 933 



After the primary alcoholii' fermentation is completed, a slow secondary fermenta- 

 tion set.s in, during which the beverage mellows and imjiroves in quality. One of 

 the results of this secondary fermentation was found to be a decrease in the acidity 

 of the cider. 



The effect of various yeasts on the production of cider was studied. Yeasts 

 obtained from black grapes, white grapes, Kingston-Black apples. Gin apples, and 

 cider yeasts from foreign sources, respectively, were used to inoculate cider. In every 

 instance a different quality of cider was produced. The best quality of cider was 

 obtauie<l by blending the natural juices which had been fermented without the 

 addition of selected yeast*<, strict attention being given to cleanliness. It is believed, 

 however, that in order to make cider of the best quality it will l)e necessary to secure 

 pure yeast cultures from the apples which grow in the neighborhood. In the use of 

 pure yeasts it was found that the juice fermented more slowly, kept clearer, and the 

 sugar could be retaine<l longer in it than when the juice was allowed to ferment 

 naturally. 



Experiments with oily cider tended to show that the organisin causing the disease 

 belonged to the anaerobic order. Thorough aerating of the cider tended to improve 

 it.s quality. Much of the "sick" cider which the author examined was found to 

 contain sulphuretted hydrogen, which developed as a result of sulphuring the bar- 

 rels. The flavor of cider was found to be greatly influenced by the quantity of non- 

 fermental)le constituents present. When undiluted apple juice was fermented in 

 com^Jarison with the same juice diluted with one-half its own volume of water and 

 sufficient sugar then added to make the liquid contain the same amount as the whole 

 juice, the resulting cider from the diluted juice had a much better flavor than that 

 from the whole juice. Flavor is also influenced by the nature of the fermentation, 

 as was shown when yeasts of different origin were employed in fermentation. Bac- 

 teria rather than yeasts appeared to be the main cause of those changes generally 

 designated as secondary fermentation or ripening of cider. It is believed, as the 

 result of 10 years' work, that the secret of success in cider making, as in dairying, is 

 cleanliness. 



Making unfermented wine (Ar/^-. Gaz. Xeiv South Wales, 14 {lOOS), No. 3, p. 

 256). — Practical directions for jireparing unfermented grape juice. 



Alcoliolic fermentation in the presence of sulphurous acid, A. Lebedev {Selsk. 

 Khoz. i Lyesoc, 208 {1903), Jan., pp. 194-200). — The author reports experiments 

 in which satisfactory fermentation was obtained in wine must containing 1 gm. of" 

 sulphurous acid (SO,) per liter. — p. fireman. 



The technology of sugar, J. G. McIntosh {London: Scott, Greenwood it Co.; New 

 York: D. Vim Xosfrand Co., 1903, j)p. ATT' + 408, figs. 83). — Different sections of this 

 book deal with classification of sugars, beet sugar, cane sugar, sugar refining, and 

 selection of sugars. 



Manual guide for the manufacture of sugar, R. Teyssier {Manual guide de la 

 fid>riratio)i du Hurre. Park: C. Xaud, 1H04, pp. 4^'5,figs. 139). — This book is said to 

 be intended for the use of sugar makers, directors, and chemists of sugar factories, 

 etc., and more especially for managers and overseers. 



Decorticating ramie {Indian Agr., 28 {1903), No. 7, p. 217).— A. patented 

 method baseil upon- the use of more or less concentrated sea water or a solution hav- 

 ing the approximate composition of sea water for freeing the fiber from gummy 

 suVjstances is briefly described. 



A short text-book of chemical technology, <i. Schui.tz and J. IIokek (Karzes 

 Lehrhuch der chetnixchen Technnlot/lr. Sluttgari: Ferdinand Euke, 1903, pp. 364, figs. 

 1.51). — The subjects treated in this bo<jk are fuels and the generation of heat; water; 

 sulphur and sulphur compounds; alkali salts; hydrochloric and nitri(! acids; inflama- 

 bles and explosives; commercial fertilizers; cement, mortar, and artificial stone; 

 glass and waterglass; pottery and jwrcelain; metallurgy; fats an<l oils; soaps, waxes. 



