zooLoar and botany, microscopy, etc. 
255 
containing metliylene-blue anilin oil (4). The sections can be de- 
hydrated in the alcohol without injury to the stained bacteria. The 
sections are now transferred to pure anilin oil, in which they are rinsed 
and then placed in some essential oil, as turpentine, where they should 
remain for two minutes. In order that the sections should bo perfectly 
cleared they are transferred from the turpentine to xylol, from which 
they are mounted in balsam. It is recommended that the sections 
should pass successively through two xylol baths in order to secure 
absolute elimination of the anilin oil. The xylol may be used for a 
considerable number of sections. 
Dr. Kiihne employs a glass rod for transferring the sections from one 
solution to another instead of the ordinary spatula or section-lifter. 
The end of a small glass rod is immersed in the fluid containing the 
section, which is allowed to fold itself over the rod, and in this position 
it is lifted from the fluid. The end of the rod is then gently immersed 
in the second liquid, where the section unfolds itself from the rod and 
floats upon the surface. In this way the danger of tearing the section is 
diminished and the time required for their transfer from solution to 
solution is much shortened. This is an important consideration where 
a large number of sections are to be stained. 
(1) Garhol-methylene-hlue. — This is prepared by grinding in a mortar 
1 • 5 grams of methylene-blue with 10 ccm. of absolute alcohol until dis- 
solved ; 100 ccm. of 5 per cent, carbolic acid are gradually added and 
thoroughly mixed with the alcoholic solution. The resulting liquid is 
preserved in a well-stoppered bottle, until used. When only a small 
quantity is to be employed it is better to prepare only a half, or a quarter 
even, of the above quantity, as its staining power is diminished by long 
standing. It should always he filtered before using. 
(2) Weak acidulated water. — To 500 ccm. of distilled water add 
10 drops of nitric acid. 
(3) Lithium-water. — To 10 ccm. of distilled water add from 6 to 8 
drops of a saturated watery solution of carbonate of lithium. The satu- 
rated solution may be used as a decolorizing agent in sections with 
over-stained nuclei. 
(4) Methylene-hlue anilin oil. — About one-half gram of methylene- 
blue is ground in a mortar with 10 ccm. of pure anilin oil. When the 
011 is saturated with the colouring matter the entire mass is poured uu- 
filtered into a vial, where the undissolved colouring matter will settle, 
leaving the saturated supernatant oil clear. To a watch-glass of pure 
anilin oil add a few drops of the saturated methylene-blue-oil until the 
desired degree of colorization is obtained. 
(5) Mounting-, including- Slides, Preservative Fluids, &c. 
New Form of Clip for Balsam Mounting.* — Mr G. H. Bryan says 
that there are few practical microscopists who do not admit that the 
spring-clips which have for so many years been used in mounting 
objects in balsam are a failure. The usual query which has been 
repeatedly asked is, “Why does air run in as soon as the clip is 
removed ? ” The answer is pretty obvious, viz. that the object yields 
to the pressure of the clip as long as it is subject to it, but as soon as 
* Journ. of Microscopy, iii. (1890) pp. 45-7 (1 fig.). 
