ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
117 
fluorescin-alcoliol (i. e. until no more dye was given off). The fluorescin 
was washed out in 95 per cent, alcohol. Then amlin oil for some 
minutes. The anilin oil was removed with oil of lavender, then xylol, 
and finally balsam. 
Decoloration of Osmized Fat by Turpentine and other Substances.* 
— Dr. W. Flemming gives the results of experiments on fat stained with 
osmic acid, and afterwards acted on by various substances. Turpentine 
decolorizes in If hours, ether in 4 hours, xylol in 5^ hours. Canada 
balsam dissolved in turpentine and thinned with xylol in 4^ hours, 
dammar dissolved in turpentine and chloroform in 3 hours ; balsam dis- 
solved in xylol, no action observed ; chloroform, no action ; oil of cloves, 
no action. 
Hence xylol is much to be preferred to turpentine. But chloroform 
and oil of cloves are obviously safer. 
(5) Mounting-, including Slides, Preservative Fluids, &c. 
Manipulation of Paraffin-imbedded Sections.! — Prof. H. Strasser, 
who keeps on devising alterations in the technique of paraffin imbedding, 
describes a new procedure, the chief feature of which is the manij)ulation 
of the section on a “ provisional or temporary slide. 
The provisional slide i& thin well-sized paper, one side of which 
has been smeared with a gum solution containing 10 per cent, by 
volume of glycerin. The section is then stuck on with a solution of 
collodium simjdex 2, castor oil 1 — and then fixed down by brushing over 
the upper surface with collodium cone. dupl. 2-3, castor oil 2. 
The preparation is then removed to turpentine to dissolve out the 
oil and the jmraffin, and also set the collodion. The plate, i. e. the 
imbedded section plus the paper, is then placed in an aqueous or 
watery-spirituous fluid for staining or other purposes. During the water 
stage the gum is dissolved, and the section in its collodion case thereby 
set free. The next step is to put this into turpentine again, after 
which it may be mounted in a resinous medium on a temporary or per- 
manent slide. 
Owing to the fact that the paper, i. e. the provisional slide, which 
plays the principal part in this procedure, becomes dyed in its transit 
through the staining solutions, the method, as the author confesses, 
is at present somewhat imperfect. 
New Method for Fixing Sections.! — Dr. W. M. Gray who describes 
the following method, says that it is identical in its procedure with 
the “ gum arabic process,” provided the tissue from which the sections 
are cut has been successfully stained in mass. “ The process is as 
follow'S. Dissolve one part of gold label gelatin in one hundred parts 
of warm distilled water ; after the gelatin has dissolved, filter and add 
a crystal of thymol, to prevent the formation of fungi. If, on standing, 
the gelatin coagulates, warm slightly and use the fixative in the same 
manner as the gum arabic solution, or in other words, flow a small 
quantity on the perfectly clean slide, place the object on the fluid, and 
heat gently until the sections or series of sections are flat and free from 
* Zeitschr. f. Wiss. Mikr., vi. (1889) pp. 178-81. f T. c., pp. 150-G3. 
X The ^Microscope, ix. (1889) pp. 325-0. 
