106 MEMORANDA. 
Microscopical Society, is now made by Mr. Baker, of Holborn; 
the pattern has also been sent to Messrs. Claudet & Houghton. 
For operations where a large quantity of water in reserve 
is wanted, and there is no necessity for the object to be nearly 
close to the stage, Mr. Beck’s slide answers admirably. 
Those who are able to cut glass with a diamond can easily 
make the American slide for themselves at the cost of a few 
pence ; the best tool for drilling the hole is a small triangular 
file with the point ground to the form of a pyramid, used with 
turpentine ; the glass being pressed against a piece of cork for 
support, the points can be made without heat by using thick 
gold size.—W. T. SurroLtx, Claremont Lodge, Park Street, 
Camberwell. 
Mounting Diatoms.—Can you or any of your readers inform 
me how to make microscopic objects (diatoms, for instance) 
stick on a slide after they are arranged? I have tried many 
ways, but none of them answered to my satisfaction when I 
compared my slides with the beautiful ones arranged by the 
London mounters. I find no difficulty in picking off and 
arranging the diatoms in any patterns, but what I fail in is to 
make them adhere to the slide after I have put the balsam on 
them. I am now engaged with some beautiful forms from 
the Montray and Les Angeloss deposits, and it is exceedingly 
annoying, when I have got the diatoms arranged nicely on 
the slides, to find them floating away; when the balsam is 
put on I have no doubt there is a very simple way of over- 
coming this difficulty, and perhaps you or some of your 
numerous subscribers can assist me to it.—W. Warp, Hull. 
We have recently had an opportunity of examining two 
new forms of instruments constructed by Messrs. Murray 
and Heath, in one of which the great object of furnishing a 
stand at a low price, but which should yet be capable, if 
desired, of being adapted to the use of the highest powers, 
and fitted for the addition of all accessory apparatus, has, it 
seems to us, been very satisfactorily obtained. The stand 
itself is remarkably steady, and the objectives—which, we 
understand, are furnished with it for £5—are a + inch of 75° 
and an inch of 15°, both, as tested by ourselves, of excellent 
quality. 
The second instrument is one which has been contrived for 
