ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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tine, pure turpentine, cold paraffin and turpentine. It was then put 
into warm paraffin and turpentine for 6 hours, then into melted paraffin 
(50°-55°) for 6 hours. It was then imbedded in the paraffin and 
cut into ribbons upon a Reicliert-Thome microtome, the sections being 
20 ix (1/250 in.) thick. The ribbons were fixed on the slide with 
white of egg and glycerin. The slide was warmed to melt the paraffin, 
which was then washed away with turpentine, washed next with absolute 
alcohol, then 90 per cent, alcohol, then water (distilled), then stained 
with fuchsin about two seconds, next washed with distilled water, 90 per 
cent, alcohol, absolute alcohol, and turpentine in succession. Canada 
balsam in chloroform was then poured over the specimen and the cover- 
glass laid on. I have given every step taken in the operation. The 
haematoxylin did not penetrate, hence the staining by fuchsin was 
necessary.” 
C4) Staining 1 and Injecting. 
New Method of Injecting Fluids into the peritoneal cavity of 
animals.* — Dr. A. F. Stevenson and Dr. D. Bruce describe a method 
for injecting fluids into the peritoneal cavity without danger of wounding 
the intestines with the point of the hypodermic needle. The needle is 
curved, its anterior half being solid, while the posterior part is hollow, 
the opening being in the middle, i. e. at the junction of the two halves. 
It may be fitted to any syringe. When using it, the abdominal wall of 
the animal is pinched up with thumb and forefinger of two hands, and 
then the needle plunged through until the middle (the opening) is in 
centre of the pinched-up tissue. Hence when the skin is relaxed the 
opening of the needle is freely within the peritoneal cavity. 
Demonstrating the Cerebral Vessels of Mammalia.! — For studying 
the distribution of the cerebral vessels of Mammalia at various periods 
of intra- and extra-uterine life, Sigg. G. Valente and G. d’Abundo found 
that an aqueous solution, not stronger than 0*5 per cent., of silver 
nitrate, was more suitable than all other injection masses. By the 
injection of coloured gelatin the vessels, especially in the embryo, were 
dislocated from their normal position. This inconvenience is avoided 
by the silver solution, while at the same time, owing to its penetrating 
the walls of the vessels, the endothelium and the perivascular lymphatic 
sheaths are made clear. Brains injected in this way cannot, of course, 
owing to the precipitation which would ensue, be treated with the 
ordinary fixative media. After being exposed for twenty minutes to direct 
light they were at once transferred to alcohol. For staining, Meynert’s 
method was preferred, and it is advised to stain the sections on the slide. 
Three useful Staining Solutions.^ — Dr. R. Haug gives three formulae 
for staining solutions which are stated to be extremely effective. 
(1) Haematoxylin in acetic acid-alum. 1 grm. of haematoxylin is 
dissolved in 10 ccm. of absolute alcohol, and this mixed with 200 ccm. 
of liquor aluminis acetici (German Pharmacopoeia — see also “ Extra 
* Brit. Med. Journ., June 6, 1891, p. 1224 (2 figs.). See also Centralbl. f. 
Bakteriol. u. Parasitenk., ix. (1891) pp. 689-90. 
f Atti Soc. Scienze Nat. Pisa Mem., xi. (1890) 14 pp., 1 pi. See Zeitschr. f. 
Wiss. Mikr., viii. (1891) p. 92. 
X Zeitschr. f. Wiss. Mikr., viii. (1891) pp. 51-2. 
