ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
147 
tannin and 1/2 to 1/4 per cent. HC1. The preparations are next care- 
fully washed and placed in iodine water. Gram’s iodine or one drop of 
iodiue tincture to 10 ccm. water does very well, but iodine mixed with 
water and allowed to stand for 24 hours (shaking frequently) answers 
better. 
In the iodine solution the covers remain for about one hour ; they 
are then washed in water, and stained with gentian-violet. The violet 
solution is made in a 25 ccm. test-tube. One drop of a saturated alco- 
holic solution of gentian-violet solution is mixed with 10 ccm. distilled 
water. Half of this is poured away and the test-tube filled up with 
anilin water. In this solution the covers remain for about 30 minutes. 
Afterwards the author advises using a less quantity of hydrochloric 
acid, and to have three different solutions, viz. : — Two per cent, tannin, 
with 1, 2, and 3 per 1000 HC1. The 1 per 1000 may be made by 
mixing 10 grm. of a 2 per cent, tannin solution and 2 drops of 8 per 
cent. HC1. 
Impregnation of Bone Sections with Anilin Dyes.* — Herr N. 
Matschinsky finds that saturated aqueous solutions of anilin pigments are 
excellent for demonstrating the* growth-appearances of bone. The pig- 
ments used were eosin, safranin, gentian-violet, methylen-blue, methyl- 
green, iodide-green, and fuchsin, and though all were satisfactory, eosin 
and safranin gave the best results. 
The bones examined were sectioned transversely and longitudinally, 
and were both macerated and fresh. If fresh, the fat was removed by 
immersing the sections for half an hour in ether, and after having been 
polished up, the dust removed, and washed in water, they were trans- 
ferred to the staining solution. 
Macerated bones were allowed to remain for about 48 hours, but if 
kept at a temperature of 40° C., the staining was more rapid. Sections 
of fresh bone stained more slowly. 
When removed from the staining solution the sections were dried, 
and having been again carefully polished up, were examined in air or in 
Canada balsam. 
From examination of different bones and bones of different ages 
(young, adult, old), it was found that the staining was proportionate to 
the ^changes going on. Thus, in young bone the staining was more 
pronounced in the subperiosteal and subendosteal regions than in adult 
bones, and much more than in old osseous tissue. 
(5) Mounting 1 , including Slides, Preservative Fluids, &c. 
To rectify Turpentine for Microscopical Use.j — Mr. Charles C. Faris 
writes: — As it is difficult to obtain nice, clear turpentine for micro- 
scopical purposes, I want to give other workers the benefit of my expe- 
rience in rectifying the ordinary fluid. I proceed as follows : — 
Take one pint of the common turpentine and mix in a quart bottle 
with 4 oz. of 98 per cent, alcohol. Agitate well, and let stand until 
the two fluids separate. Decant the turpentine (which will form the 
lower layer) from the alcohol, and mix it with one pint of clear water. 
* Anat. Anzeig., x. (1890) pp. 325-36. f The Microscope, x. (1890) p. 179. 
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