548 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
(3) Dehydrate in absolute alcohol. (4) Decolorise in clove oil until 
the red nuclear stain shows pretty well. (5) Xylol. (6) Balsam. 
By this method the nuclei are stained red, the plasma yellow, and 
bacteria, stainable by Gram’s method, indigo-blue. If not stainable by 
Gram’s method then the bacteria are red. 
For very thin sections, dehydration in alcohol is hardly necessary, 
and merely mopping with blotting-paper may be sufficient. For cover- 
glass preparations the use of alcohol is to be avoided. 
New Staining for Nervous Tissue.* — Herr P. Kronthal stains 
sections of brain and cord by immersing them in a mixture of equal 
parts of 10 per cent, formalin and saturated formate of lead solution 
for five days, and then for a similar period in sulphuretted hydrogen 
and formalin solution. The sections are then washed, treated with 
alcohol and xylol, and imbedded in balsam. Not only the ganglia and 
nerve-cells, but the finest branches of the nerves, show a deep brown 
impregnation, which is fast and lasting. 
Staining Cell-walls.j — M. J. Chalon communicates the results of 
the third series of experiments on staining cell-walls. The staining 
solutions used were magenta-red, anilin-blue, crocein, tropgeolin, neutral 
red, alkaline blue, naphthylene-blue, congo-red, erythrosin, fuchsin, 
cyanin, and ruthenium-red. The double stains tried were alkaline blue 
and fuchsin, alkaline blue and eosin dissolved in oil of cloves, logwood 
and safranin, cyanin and congo-red, alkaline blue and safranin, solid green 
and delta purpurin, chrysoidin and azurin, cyanin and eosin, naphthy- 
lene-blue and acid-green, alum-methylen-blue and ruthenium-red, acid- 
green and neutral red. The results from alum-methylen-blue and 
ruthenium-red are described as superb. Methyl-green may be sub- 
stituted for methylen-blue. The preparations are immersed for 5-10 
minutes in aqueous alum-methylen-blue solution, washed in water, and 
then transferred to aqueous solution of ruthenium-red. Later on the 
author recommends alum-carmine and iodine-green, as giving the best 
differentiation and most lasting results. Other combinations recom- 
mended are alum-carmine and methylen-blue, prussian blue and 
safranin. 
Fixation, Staining, and Structure of Protoplasm. J — Prof. A. 
Fischer’s work on the fixation, staining, and structure of protoplasm 
is an exhaustive critical examination of the technique which has been 
adopted and pursued in modern cell research, and of the theories and 
speculations which have arisen in consequence of these researches. 
The first part deals with fixation generally, that is to say, with the 
material to be fixed, fixing agents, the appearances produced by fixatives 
acting on albuminous bodies, and fixation of cell-contents. 
The second part is devoted to staining, and the subject is discussed 
on lines similar to those of fixation. That is to say, there is considera- 
tion of the substances to be stained, and of the various pigments and 
staining fluids used in the process. 
* Neurol. Centralbh, March 1899. See Zeitschr. f. angew. Mikr., v. (1899) p. 145. 
f C.R. Bull. Soc. Roy. Bot. Belgique, 1898, xxxvii. (1899) pp. 59-90. Cf. this 
Journal, 1898, p. 685. 
X Jena, Gustav Fischer, 1899, x. and 362 pp., 1 pi. and 21 figs. 
