1886.] Scientific News. 205 
strong hydrochloric acid to ten parts of water. And here it may 
be added that in case the bleaching does not readily commence 
upon immersion in the bleaching solution, the action may be has- 
tened by a previous dipping in the dilute hydrochloric acid. In 
the bleaching solution a crust of calcic carbonate, formed by the 
union of the calcic hydrate of the solution and the carbonic diox- 
ide of the air, is deposited on the wings, and this calcic carbonate 
the final wash in dilute acid will remove. As soon as the calcic 
carbonate has disappeared, and all bubbling, consequent upon its 
decomposition by the hydrochloric acid, has ceased, the wings 
should be well soaked in pure water. They may then be secured 
on cards with a mucilage of gum tragacanth ; or upon glass by 
the proper transfers, through alcohol and chloroform, to Canada 
balsam. ; 
A solution of sodic hypochlorite, known as Zau de Labarraque 
or a solution of potassic hypochlorite, known as Zau de Javelle, 
when used in place of the solution of bleaching powder does not 
leave a deposit of calcic carbonate on the wings and thus dispense 
with the wash of dilute acid. A solution of zinc hypochlorite 
acts more delicately than a solution of sodic hypochlorite, and 
may be used in płace of the latter, as may also solutions of alu- 
minic hypochlorite, or magnesic hypochlorite. 
my k e 
sVe 
SCIENTIFIC NEWS. 
— The recent meeting of the Society of Naturalists, held at 
Boston, December 29 and 30, will long be remembered with 
pleasure by thosé who had the good fortune to be present. The 
excellent plan of the founders of the society of limiting the 
range of the papers to the discussion of methods of teaching and 
research, leaves but small foothold for bores, and, indeed, the series 
of papers furnished an exhilarating succession of suggestive and 
easily grasped ideas. Most of the sessions were held in the 
physiological lecture-room of the new Harvard Medical School 
building and just adjoining the laboratory of Dr. Bowditch, 
which is probably unparalleled for its wealth of ingenious and 
Mective apparatus, designed and made on the spot. The courte- 
sies of the Harvard members of the society very agreeably occu- 
pied the hours not strictly devoted to business. 
-— Professor T. J. Burrill deals, in the Botanical Gazette, p. 334, 
ath two mechanical effects of cold upon trees—the radial split- 
ting of wood and bark, and the separation of bark or wood layers 
i a concentric way. . 
oe first is explained by water freezing in plates parallel to the. 
ce of an organ, and then, additions being made to the base, 
