2 e 
1885.] Scientific News. 429 
schnitt’s Papers and Preparations relating to Pollen-tubes, by N. 
L. Britton. The rest of the number is given to the Proceedings 
of the Society, Miscellanea, and an Index to Articles of Interest 
to Microscopists. 
In the meeting of December 5th, J. D. Hyatt speaks of Hy- 
drogen Peroxide as a Bleaching Agent, but gives no details of 
the process. 
This journal is edited by Benjamin Braman, and is to be pub- 
lished in nine monthly numbers, from November to July, inclu- 
sive. 
' Metuop or MAKING ABSOLUTE ALcoHnoL.—Dr. Sharp states 
that absolute alcohol is prepared in Ranvier’s laboratory by add- 
ing anhydrous cupric sulphate to ninety-five per cent alcohol.? 
Pulverized cupric sulphate is heated to red heat in order to 
drive off the water of crystallization ; when cool the white pow- 
der is placed in a wide-mouthed bottle, holding about a liter, and 
three-fourths full of alcohol. The bottle is quickly closed and 
the whole shaken. After standing a day or more—with occa- 
sional shakings—it is decanted and the operation repeated, espe- 
cially if the cupric sulphate shows much of the blue color due 
to the reassumption of water. ; 
As a test a drop of the alcohol thus dehydrated may be mixed 
with a drop of turpentine on a glass slide, and examined under 
the microscope; if no particles of water are to be seen the alco- 
hol is absolute enough for all practical purposes. 
30% 
SCIENTIFIC NEWS. 
* 
character of the bottom. Over the side of the vessel is a long 
sounding bar or tube, in length 10% feet, or more, which bar 
works freely round a fixed center inside the boat. This fixed. 
center is placed in the middle of a circular dial on which are 
marked fathoms or feet, a duplicate dial being placed in the cap- 
tain’s cabin. On mooring the boat over a shoal rising to the sur- 
depths of the shoal under the surface of the water. It has been 
found that the vibrations of the sounding bar differ in degree 
when the boat moves it along different formations, thus enabling 
the observer, after very short experience, to record in his note- 
1 Roscoe and Schorlemmer state that anhydrous cupric sulphate is a good test for 
the presence of water, but not a suitable means for preparing absolute alcohol. 
