ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
693 
This is not usually employed for mounting purposes, but may be 
used in cementing glass and metal parts of instruments. 
Zinc-white cement, German formula : — 1, mastic, 10 pts. ; 2, dammar, 
4 pts. ; 3, sandarac, 4 pts. ; 4, Venetian turpentine, 1 pt. ; 5, turpentine, 
20 pts. ; 6, benzol, 10 pts. ; 7, zinc-white. 1, 2, and 3, powdered are 
mixed in a well-corked bottle with 4, 5, and 6 ; shake well occasionally ; 
after several days filter, and triturate in a mortar with zinc-white in 
quantity sufficient. Dilute if necessary with benzol. 
Zinc-white, English formula: — 1, gum dammar, 3 pts.; 2, gum 
mastic, 1 pt. ; 3, benzol, 6 pts. Dissolve powdered 1, 2, and 3 in a 
well-corked bottle ; when dissolved filter, and mix carefully in water 
with zinc-white. 
Marine glue India-rubber shreds, 2 oz. ; shellac, 2 oz. Dissolve 
the rubber in mineral naphtha, add the powdered shellac, heat 
until liquefied, and mix well together. This gives solid marine glue, 
and requires heat in its application. Great care should be observed in 
having all fire and flame removed while there still remains naphtha in 
the mixture. 
Lovett’s cements : — Powdered white lead, 2 parts ; powdered red lead, 
2 parts ; powdered litharge, 3 parts ; gold size. The white and red lead 
and the litharge must be very finely powdered ; for use this powder is 
mixed with gold size to the consistency of cream, and the cells immedi- 
ately fastened to the slide. They are secure in two weeks. This stands 
considerable heat, and is excellent for fluids containing some alcohol. 
Make a little only of the mixture with gold size at a time, as it 
hardens quite rapidly and becomes useless. 
King’s cement and lacquer. — Satisfactory, and highly recommended 
by some. 
Brown’s rubber cement. — Very good for finishing slides. 
Miller’s caoutchouc cement. — Sold in England by opticians. It is a 
most excellent and quickly drying cement. 
Hollis’s glue. — Somewhat similar to Bell’s cement. 
Nearly, if not all the foregoing can be most advantageously bought of 
the opticians and dealers in microscopical material. 
(6) Miscellaneous. 
Coco-nut-water as a Culture Fluid.* — Mr. G. M. Sternberg points 
out that the fluid contained in unripe coco-nuts is quite transparent, 
with a specific gravity of 1 * 02285. Chemical analysis showed that it 
was composed of water 95 per cent., ash 0*618 per cent., glucose 3*97 
per cent., fat 0*119 per cent., albumen 0 * 133 per cent. This fluid forms 
an excellent medium for numerous kinds of micro-organisms. There is 
no need to sterilize it, if it be removed with the necessary precautions. 
As its reaction is slightly acid, it must be neutralized before being 
used for cultivating certain kinds of pathogenic micro-organisms. 
* Philad. Med. News, 1890, p. 262. See Centralbl. f. Bakteriol. u. Parasitenk., 
ix. (1891) p. 834. 
3 C 
1891. 
