54(3 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Excess of fixing-fluid and paraffin can now bo wiped from the slide. 
Staining can be at once proceeded with, or the slides can stand for a time 
protected from dust 
(5) Staining . — Dissolve the paraffin from the section by two or three 
washings of naphtha, which is allowed to stand on the slide for about a 
minute. Then wipe the slide, and wash off the superfluous naphtha with 
methylated spirits. 
The following stains give splendid results : — Logwood, logwood and 
eosin, logwood and Bismarck brown, and alum-carmine. To get the 
best results with logwood, the following method should be used : — Stain 
the section for three minutes or more in the Ehrlich's hematoxylin 
solution. Then place it in a bowl of distilled water containing a few 
drops of hydrochloric acid until it appears of a pale port wine colour. 
The acid dissolves the stain from all parts save nuclei. Then place in 
a very dilute alkaline solution (sodium bicarbonate) until it turns blue. 
The alkali deepens the stain in the nuclei. 
If eosin is to be used as a contrast stain, wash the section in water 
and place it in 1 3 per cent, eosin solution (if Bismarck brown, in a 1 4 
per cent, solution) for two minutes. Wash in water, then in methylated 
spirits, and finally dehydrate in absolute alcohol. Clear up in clove 
oil or xylol ; mount in balsam dissolved in xylol, naphtha, or benzol. 
It is to be observed that naphtha serves for the early stage of soaking 
in paraffin, for dissolving the paraffin from the mounted sections, and for 
dissolving the balsam which covers them. 
If it is desirable to stain the tissue en masse before cutting, the follow- 
ing method is valuable: — Stain the spirit-hardened tissue for 18-24 
hours in a borax-carmine solution prepared as follows : — Add 4 grm. 
borax to 100 ccm. aq. dest., and heat to boiling point. Add 2J grm. 
carmine, and boil for 12 minutes. Allow it to cool, and add an equal 
bulk of a 70 per cent, solution of alcohol. After allowing it to stand 
for three or four days, filter. 
The now deeply stained tissue is partly decolorized by being placed 
for 12 or 15 minutes in a mixture of acid, hydrochlor. 4 drops, abs. 
alcohol 70 ccm , aq. dest 30 ccm. 
It is then placed in methylated spirit for three hours, and afterwards 
in alcohol for 18-24 hours. Clear up in clove-oil— denoted by its 
sinking. 
It is now ready for the paraffin process, being first soaked in naphtha, 
Ac. When the sections are cut they are fixed on the slide in the usual 
manner, the paraffin dissolved out with naphtha, and the mounting com- 
pleted with balsam/’ 
Sections of Staminate Cone of Scotch Pine.* — 5Ir. Charles E. Bessey 
sends the following contribution from the Botanical Laboratory of the 
University of Nebraska to show what can be done by the paraffin 
imbedding process in cutting and mounting objects which otherwise 
would fall to pieces. The preparation was as follows in detail : — 
The cone was first put into 35 per cent, alcohol for 12 hours. Then 
successively 12 hours each in 50 per cent, alcohol, 75 per cent, alcohol, 
haematoxylin, 90 per cent, alcohol, absolute alcohol, alcohol and turpen- 
* Amer. Mon. Micr. Joura., xii. (1891) p. 56. 
