548 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Pharmacopoeia ”). The fluid, at first violet-black, becomes brownish- 
black in the course of a few weeks, and its maturation may be hastened 
by the addition of a few ccm. of saturated lithium carbonate solution. 
It is advised to overstain the preparation with this solution, and to 
decolorize with hydrochloric acid-alcohol. The sections are then placed 
in tap water until they become blue. Any contrast dye may be used 
afterwards. 
(2) Alum-borax-carmine with acetic acid-alum. This gives similar 
but better results than alum-carmine. It is prepared by rubbing up 
1 grm. carmine with 1 grm. borax and 2 grm. ammonia-alum, and then 
boiling this with 100 ccm. of liq. aluminis acetici for half an hour or 
longer. It is then decanted, and after 24 hours filtered. 
(3) Ammonia-lithium-carmine with ammonium chloratum. This 
gives a fine deep strawberry red colour in 1-3 minutes. Overstained 
sections may be differentiated with hydrochloric acid-alcohol. After- 
wards they are placed at once in absolute (picric) alcohol. It is prepared 
by rubbing together 1 grm. carmine with 2 grm. ammonium chlorate, and 
boiling in 100 ccm. water. When cold, to the solutions are added drop 
by drop 15-20 ccm liq. ammonii caustici and lithium carbonicum from 
0*3 to 0*5. Filter. The solution is ready for use at once, and is very 
permanent. 
Fixation of the Stain in Methylen-blue Preparations.* — Prof. A. S. 
Dogiel finds that the addition of osmic acid to the picrate of ammonium 
solution used for fixing methylen-blue is attended with several advantages, 
not the least of these being that it hardens the tissue just a little, and, 
secondly, that it stains the medullary sheath of nerves black. The 
solution is made by adding 1 or 2 ccm. of a 1 per cent, osmic acid 
solution to 100 ccm. of a saturated aqueous solution of ammonium 
picrate. The stain is fixed by immersing the preparation for 18-24 
hours in the mixture. It is then transferred to glycerin, diluted with 
water, in which the colour of the nerves will keep for quite a long time. 
Should it be necessary to impart a consistence to the object so that it 
may be sectioned, the author uses a greater quantity of osmic acid (25- 
30 ccm. ammonium picrate solution ; 1-2 ccm. 1 per cent, osmic acid). 
In this solution the object remains for 24 hours, after which it may be 
imbedded e. g. in elder-pith, liver, &c., and sectioned. 
Hints on Preparation of Tumours injected during life with anilin 
pigments. t — In order to examine sections made from malignant tumours 
which have been treated by injection with aqueous solutions of chemi- 
cally pure anilin dyes, it is necessary, says Dr. E. Hang, to adopt a 
certain procedure. The dyes usually injected intra vitam by the surgeon 
are methyl-violet and methylen-blue. If, therefore, a piece of a tumour 
injected with these dyes be excised before their absorption, a blue-violet 
mass is obtained. This mass must be hardened, and for this purpose 
alcohol must be altogether excluded. Hardening may be effected in 
Erlitzki’s fluid or some other combination of chromic acid salt and 
copper, or picric acid ; better than these is cold saturated solution of 
sublimate. In this pieces, the sides of which are about 0*75 cm., 
are left for about 24 hours. The sublimate crystals are removed by 
* Zeitschr. f. Wiss. Mikr., viii. (1891) pp. 15-9. t T. c., pp. 11-15. 
