SCIENTIFIC SUMMARY. 
201 
the Flora Boreali- Americana. The notes of Mr. Watt’s are of especial 
interest, hut are too long for insertion here. 
To those interested in the Laminariacece. — It has been recently stated by 
Dr. Lawson that Dr. A. F. Le Jolis, of Cherbourg, France, is engaged in a 
monograph of the whole group of the Laminariacece, that for such a study 
materials are never too numerous, and that he would be happy to receive 
a fresh supply of specimens from North America. He asks Dr. Lawson’s 
help, and that he would interest his friends in his favour. It is not neces-r 
sary that the specimens be prepared for the herbarium. On the contrary, 
he had rather they were coarsely dried, without being washed in fresh 
water or compressed. The parcels may be addressed to him, and sent by 
any vessel to France. 
The Vitality of Yeast. — Mr. H. J. Slack, in his recent interesting and in- 
structive address to the Boyal Microscopical Society, stated that M. Melsens 
made experiments last year on the vitality of beer-yeast. He found fer- 
mentation possible in the midst of melting ice, a temperature at which the 
yeast would not germinate. The life of the yeast-plant was not destroyed 
by the most intense cold that could be produced, about 100° C. below zero. 
In close vessels when the products of fermentation gave a pressure of about 
twenty-five atmospheres the process stopped, and the plant was killed. 
M. Boussingault, who was present when this communication was made to 
the French Academy, accepted the statement, on account of the known 
ability of M. Melsens, but he detailed experiments to show that other fer- 
ments had their activity destroyed by exposure to temperatures much less 
severe, or even by ordinary frost. 
T)r. Gray , of America , and Pt'ofessor S. JB. Buckley have had some con- 
siderable disputation before the Philadelphia Academy (see “ Proceedings,” 
December 1870) on the supposed new plants from Texas. Dr. Gray has 
differed from Professor Buckley materially ; consequently the latter has come 
forward to justify himself. It seems to us, from a cursory glance at his 
paper, that in some of his assertions Professor Buckley is correct, but that 
in by lar the greater number undoubtedly Dr. Gray has at present the 
advantage. Professor Buckley states, what we must deplore very much, 
that at the time of the American war u a large collection of rare plants ” 
which he had made during 1859, ’60, and ’61, in Georgia, Alabama, Missis- 
sippi, Louisiana, and Texas, which he had boxed , and started with for the 
North prior to the war, were stopped and destroyed at Lavaca, Texas. 
They were intended for, and directed to, the Academy of Natural Sciences 
of Philadelphia. 
A u Find ” of Diatoms in the Sea. — Mr. E. Bicknell, of the Museum of 
Comparative Zoology at Cambridge, Mass., exhibited to the American 
Association at their late meeting some diatoms recently thrown up by the 
sea at Marblehead, Mass. The deposit first found belonged to brackish 
water, as indicated by the nature of the diatoms and the presence of fruit 
of the Characece. The second deposit occurred about a mile from the first, 
and was purely of fresh- water origin 5 consisting of peat with fresh- water 
diatoms — Binnularia, Stauroneis, Navicida rhomboides, JV. serians , &c. 
These deposits were thrown up by a severe storm on March 31 last, and are 
believed to be the first fresh-water or brackish deposits known to exist 
