November 18, 1898.] 



SCIENCE. 



691 



filter paper, and then through two thick- 

 nesses of parchment paper. The filtered 

 fluid appeared clear and opalescent, but on 

 microscopic examination live cells were 

 fi)und. A filter was then made by putting 

 two thicknesses of filter paper in a glass 

 funnel and coating with about ^- inch of 

 gypsum. The funnel was then fitted into 

 a flask and the whole sterilized. The 

 filtrate from this was clear, but also con- 

 tained a few live cells. The filtrate re- 

 mained clear for three days and then be- 

 came clouded from growth of yeast and 

 bacteria. The same results were obtained 

 from a gypsum filter an inch thick. A 

 porous cup was then used with an aspira- 

 tor to hasten filtering. Using this filter a 

 sterile extract was obtained. This was 

 tested in 10 and 20 % cane sugar, dextrose 

 and wort solutions, but no fermentation 

 took place in any of them. The experi- 

 ment was repeated three times and at 

 37.5°C. as well as at room temperatures, 

 with negative results in every case. The 

 experiments were then repeated with an- 

 other compressed yeast which also gives 

 vigorous fermentation, but with negative 

 results in every case. Inasmuch as Biich- 

 ner now states that only certain yeasts pos- 

 sess this property, it is desirable that he 

 should name and describe the yeast or yeasts 

 which he used. 



Deterrent Action of Salt in Yeast Fermentation. 



Katheeine E. Golden. 



These experiments show that sodium 

 chloride in any but minute quantities re- 

 tards fermentation and indicate that where 

 a sponge is used, and a quick fermentation 

 desired, the salt should be added in the last 

 stages. Experiments were made on sponges 

 and stiff doughs at three temperatures, 

 23°, 37° and 40°C. The following table 

 shows the increments of fermentation in 

 inches, by half hours, in long test-tubes, 

 the temperature being negligible : 



Experiments in fermentation tubes, using 

 25 cc. volumes of Pasteur's solution with 

 cane sugar, and equal quantities of yeast 

 (1 gram of dry yeast cake) and varying 

 quantities of salt, gave the following re- 

 sults : In the control tube the fluid was 

 driven from the closed end in 23 hours ; 

 with 4% salt the fluid was driven out in 

 37 hours ; with 8% salt, in 38 hours ; with 

 12% salt, in 47 hours; with 16% salt, in 7 

 days. 

 Leaves of Red Astrachan Apple immune from 



the Attach of Gymnosporangium Macropus. 



Professor W. J. Beal. 



Eecords failure of disease to spread from 

 infested cedar trees to two young Astrachan 

 apple trees, purposely planted near, and 

 also negative result of several inoculation 

 experiments, all made in 1897. In 1898 

 experiments were repeated with- same re- 

 sult. States that Professor L. E. Jones, of 

 Vermont, has had the same experiance. 



Notes on Stewarfs Sweet Corn Germ, Pseudo- 

 monas Stewarti n. spi. Dr. Erwin P. 

 Smith. 



Abstract omitted on account of its 

 length. See Proceedings of the Associa- 

 tion ; also a reprint from the same. 



A Bacteriological Study of Pear Blight. Lil- 

 lian Snyder. 



The greater part of this paper describes 

 a non-parasitic organism which was found 

 associated with Bacillus amylovorus in blight- 

 ing trees. This organism is white and on 

 solid media its colonies closely resemble 

 those of pear blight. It also resembles the 

 latter morphologically. Both germs grew 



