150 THE MICROSCOPICAL NEWS. 
should now be taken at ten inches with the camera-lucida in the 
usual way. The power of the microscope, divided by the previously 
determined power of the objective, will give the power of the eye- 
piece in diameters.—American Monthly Microscopical Journal. 
NOTES AND QUERIES. 
ALL Notes and Queries should be sent to Mr. George E. Davis, 
The Willows, Fallowfield, Manchester, before the 16th of 
each month. 
SUBSCRIPTIONS FOR 1883. The current year’s subscriptions became 
due in January last. Will those subscribers who have not re- 
mitted, kindly do so at once? 
PicrosuLPHUuRIC Acip is used for killing marine organisms at the 
Zoological station at Naples. It kills quickly, rapidly replaces the 
sea water, does not harden, and may be directly replaced by alco- 
hol. It is composed of a saturated solution of picric acid in water, 
one hundred parts, with two parts by measure of concentrated sul- 
phuric acid. When mixed, filter, and dilute with thrice its bulk of 
water. 
ALCOHOL has been used with much success in mounting Lophopus 
crystallinus with the tentacles expanded, by Mr. H. C. Chadwick, 
of the Manchester Microscopical Society. The spirit is blown as 
a spray upon the surface of the water containing the organisms ; it 
mixes slowly, and the tentacles are thereby not retracted. 
HoMoGENEOUS OBJECTIVES.—We have lately had an opportunity 
of examining a ;',th homogeneous immersion lens of Leitz; it has 
a balsam angle of 100° (82° B.A. being equivalent to 180” in air), 
and stands deep eye-pieces very well. 4. fe//ucida is shown as lines 
in its shorter direction, and Vavicula rhomboides come out beauti- 
fully in squares without any tedious manipulation. The price is 
but five pounds, so that this lens will be found worthy of notice by 
many microscopists. 
GuNDLACH’s New List oF OBJECTIVES.—We find Gundlach has 
listed a one-inch objective of 85°, a half-inch of 110°, and also 
some cheap glycerine immersions, of from 95° to 100° balsam 
angle. 
PHOTOMICROGRAPHS.—Dr. George Sternberg has a work in the 
