116 EXPERIMENT STATION RECORD. 



has given an account of his investigations in which he claims the 

 development of aromatic principles through the alcoholic fermentation 

 of wine in the presence of the leaves of the apple, pear, or grape, pro- 

 ducing the characteristic odor and flavor of the individual fruit. This, 

 he says, is brought about by the splitting up of certain glucosids con- 

 tained in the leaves through the action of a diastase secreted by the 

 yeast used in the fermentation. Subsequent investigations have shown 

 that the leaves of difi^erent varieties of grapes placed in the must give 

 to the wine different flavors and bouquets. If instead of the leaves an 

 extract containing the glucosids of the leaves be used in connection 

 with the pure j'east, the same result is secured. 



The author states that during the past season numerous experiments 

 were carried on in different parts of France with Ijoth white and red 

 wines which confirm his statement. One experiment is quoted in 

 which the must of an ordinary red wine was pasteurized and divided 

 into equal portions, one of which received an extract of the leaves from 

 a St. Emillion grapevine which had been prepared by mixing them 

 with a pure yeast 2 days before adding to the must; the second was 

 given a pure j^east, while a third lot was allowed to ferment in the 

 ordinaiy manner. The products of the fermentation were submitted 

 to various experts. That resulting from the fermentation in the pres- 

 ence of the extract of the leaves was pronounced far superior to the 

 others. 



In conclusion the author claims that his experiments show that by 

 the use of grape leaves from varieties of superior excellence, or of 

 extracts containing the glucosids from these leaves, even in a quantity 

 as small as 1:1000, the quality of the wine may be greatl}^ improved. 



Investigations concerning bacteria in the fermentation of 

 tobacco, J. H. Vernhout {2Ieded. S'Lands Phodentuhu olf. (1899), 

 pp. Ifit ])ls. 2). — The author has investigated the fermentation of 

 tobacco and concludes that (1) the fermentation of tobacco is due in 

 whole or in part to the chemical action of bacteria, and (2) a ther- 

 mophile bacterium plays an important role in the process of fermenta- 

 tion. In support of these conclusions he gives a detailed account of 

 his work. Germs that could flourish at SO-" C. were first isolated from 

 tobacco leaves in which the process of fermentation had been completed. 

 Two germs which he studied under the designations A and B were 

 thus isolated. Inoculation experiments were made by cutting into 

 small pieces or b}^ folding tobacco leaves in which fermentation 

 had just commenced. The pieces or folded leaves were placed in 

 petri dishes and sterilized at 120° C. for 15 minutes to 1 hour, after 

 which one dish was inoculated with a pure culture of germ A. Seven 

 experiments are recorded, of which 1 gave positive results, 4 doubtful, 

 and 2 negative. In the last-mentioned experiments fermentation took 

 place equally well in the check and in the inoculated dish. Two 



