ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
479 
was gently touched to the culture, and immersed in the water near to 
the centre of the cover-glass. A sufficient number of the bacilli were 
found to adhere to the wire to make from six to ten preparations. The 
tray containing them must next be placed in an incubator at 36°, until 
the water has evaporated. After the preparations had dried, they were 
fixed by passing them twice through the flame of a Bunsen burner, or 
better by heating, for from five to ten minutes, in the hot-air oven at 
120° to 140°. The covers were next immersed in 3 or 4 ccm. of the 
mordant in a large test-tube, and this was heated until steam began to 
come off. If there is a greyish film on the cover after washing in water, 
it can generally be removed by rinsing in alcohol, and then again in 
water. The staining fluid should now be applied in the same way as the 
mordant, and allowed to act for from one to three minutes. 
New Contrivance for Staining Sections.* * * § — M. H, Coupon describes 
a simple and inexpensive contrivance for staining delicate sections 
without touching them. Its principle consists in placing pieces of 
bibulous filter-paper in a thin glass tube of water, and moistening the 
paper with the required staining solution. The sections are then placed 
in contact with the paper and absorb the stain from it. 
(5) Mounting-, including- Slides, Preservative Fluids, &c. 
Notes on Formalin.j — Dr. W. H. Seaman, referring to the interest 
taken in this fluid, publishes some particulars which he thinks are not 
generally known. After giving some details as to the chemical charac- 
ters of the fluid, for which we must refer the reader to the original, he 
points out that it appears to be the intermediate substance produced by 
the action of the carbonic acid of the air on chlorophyll. 
Mr. D. S. Kellicott J appears to have had some doubts as to whether 
formalin was to effect all that it promised. The results of his experience 
were essentially in accord with the results already published. He has 
used it as a preservative for a variety of objects, and also in preserving 
animals for dissection. Its advantages appear to be that it is cheaper 
than any other method that gives good results. It gives results in much 
less time, the colours are better preserved, and there is less change of 
form by shrinkage or by swelling. Its penetrating power is excellent, 
so that objects preserved in it are fit for work on the internal organs, 
but it has its disadvantages, It is extremely volatile, and the jars have 
to be sealed with care, but the author has not had it in use long enough 
to decide how great an obstacle this will prove in a museum. Again, 
the watery solution will freeze, and not all museums are at all times above 
freezing point. Dr. Seaman has a high opinion of the fluid for fixing 
animal tissues. 
Formol.§ — Dr. F. Blum, who along with his father introduced formal- 
dehyde as a preservative medium, points out that its virtues depend on 
its forming a methyl-combination with albuminoids. He has many 
interesting notes on its use, and gives a bibliography of the subject. 
* Kev. Gen. de Bot. (Bonnier), viii. (1896) pp. 70-3 (2 figs.). 
t Proc. Amer. Micr. Soc., xvi. pp. 238-41. 
% The Microscope, iv. (1896) pp. 69-74. 
§ Anat. Anzeig., xi. (1896) pp. 718-27. 
