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Answers to Queries. 235 
expensive. There is a smaller work by him called ‘‘ A Manual of 
Mineralogy,” which perhaps would suit Mr. Steel. The price is, I 
think, 6/-, published by Triibner and Co., 57 Ludgate Hill, 
London. Mr. Rutley has also written a very convenient work, 
price 1/6, published by J. Murby, 32 Bouverie St., Fleet St., 
London. If Mr. Steel wants a book on the analyses of minerals 
by the blow-pipe, there are several works sold by Messrs. Griffin 
and Co., chemical manufacturers, Long Acre, London. The 
fullest is, perhaps, Ross’s “ Pyrology,” but Landauer on the 
“ Blowpipe” is a very good work. J. G. P. VEREKER. 
424.—Book on Minerals.—A good book, arranged according 
to the system used at the Museum of Practical Geology in Jermyn 
Street, is Collins’ ‘‘ Mineralogy,” published by Collins, Sons, and 
Co., at 2/6. J. A. Hoe. 
426.—Decolourising and Staining Leaves.—The bleaching is 
best done with a solution of hypochlorite of soda (the Lzg. Sod@ 
chlorinata of the chemist). Sections bleach in a few hours, leaves 
in a few days. After bleaching, wash thoroughly in running 
water for some hours. Then doubly stain with logwood and 
aniline blue or other dyes. J. A. Hoee. 
427.—Aquarium.—A good handbook on the subject is the 
Rev. J. G. Wood’s “ Fresh- and Salt- Water Aquarium,” published 
by Routledge, price 1/- J. A. Hoae. 
428.—Mounting Crystals.—Castor oil is certainly the best 
medium for mounting crystals. I have mounted many slides in 
this manner, and find that a good thick coat of gold-size makes a 
very satisfactory and lasting preparation. There is an interesting 
chapter on “ Micro-Crystallisation” in Carpenter on “The 
Microscope.” J. A. Hoae. 
429.—Stinging-Hairs.—I have found prolonged soaking in 
dilute glycerine, and finally mounting in glycerine jelly, to give 
good results. Once, with a very dry nettle-leaf, I got a good slide 
by soaking in turpentine and mounting in balsam, but this was the 
exception. J. A. Hoce. 
430.—Portland Cement.—I am sorry I cannot give the details 
of this process. The main point, however, is the heating of an 
impure lime containing clay and silica. This, on moistening, 
forms a double silicate of calcium and aluminium, which becomes 
hard and is not affected by water. J. A. Hoae. 
431.—Foraminifera.—The following operations from a paper 
by Mr. Elcock, in No. 1 of Zhe Journal of Microscopy, may be 
what ‘C.” requires :— 
1—Wash well to remove salt ; 2—Dry perfectly, allow to cool; 
3—Sift (sieves Nos. 50 to 60); 4—Float fine material in cold 
