124 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
— Never use a 4 green ’ cell. The older the cell the better, and, at 
ordinary temperatures, two weeks is the shortest space of time in which 
a cell of medium depth will become seasoned. 
Assuming the mount to be a section of vegetable tissue, the steps 
involved in its preparation would be the cutting, staining, washing, and 
dehydrating. The length of this article will not permit any reference 
to cutting, so the process of staining is next noticed. Any stain 
insoluble in the glycerin may be used. It is best applied immediately 
after the cutting of the section. After the section has acquired the 
proper depth of colour, it should be thoroughly washed, and then placed 
in glycerin. From here it goes through the next process — placing in 
the cell. In placing the section care should be exercised to have it 
exactly in the centre of the cell. With the section thus situated a drop 
of glycerin is allowed to fall upon it from the dropping-bottle. Take 
the clean cover-glass between the left thumb and forefinger, and place 
the left side in contact with the drop of glycerin ; draw it over until 
supported on the left edge of the cell- wall ; loose the hold of the left 
hand and allow the cover-glass to fall gradually by supporting the right 
edge with a needle. Having thus placed the cover-glass and centered 
it, place a clip upon it. The superfluous glycerin thus forced out is 
washed away by means of a jet of water from the wash-bottle so 
directed as not to strike under the cover-glass. Some water does get 
under, but this does no harm, as it supplies moisture which the glycerin 
otherwise would have by ‘ creeping * from the cell. 
When thoroughly dried by means of strips of bibulous paper the 
slide is ready for the last step — securing the union of cover-glass and 
cell-wall. This result is best obtained by ringing once around the 
cover-glass and allowing this coat to dry before applying cement enough 
to hide the junction of the cover-glass and cell-wall. When this latter 
step is accomplished the mount is essentially complete, but no one who 
has a pride in his work will leave the slide unstriped. There is no 
more beautiful slide than one formed of white cement and ringed with 
black. Properly labelled and cleaned, the slide is ready for the cabinet ; 
and if the due amount of care has been exercised in its preparation, it 
will always be a source of pride and pleasure to its owner.” 
An Aqueous Solution of Hsematoxylin which does not readily 
deteriorate.* — Prof. S. H. Gage writes as follows : — “ For most of the 
purposes of histology there is no more satisfactory and generally 
applicable stain than hasmatoxylin ; and experience has shown that 
aqueous solutions are on the whole preferable to those containing a 
considerable quantity of alcohol. Every microscopist knows, however, 
that aqueous solutions of haematoxylin soon begin to deposit a dark 
precipitate on the bottle and become filled with granules, and frequently 
with threads or fungus mycelium. 
As so many chemical changes are due to living ferments, bacteria, 
fungi, &c., it occurred to the writer that the deterioration of the haema- 
toxylin might be due to some living ferment or ferments, and if these 
could be eliminated the solution would retain its excellence. Experi- 
ment proved the correctness of this supposition, for an aqueous haema- 
* Microscopical Bulletin and Sci. News, ix. (1892) pp. 36 and 7. 
