540 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
in 4 fluid draclims of benzine (C 6 H 6 ) at a temperature of about 45° C. t 
and strain. Add 4 fluid oz. of carbon bisulphide, agitate thoroughly, 
and allow to cool, when the tolu solution will separate and the carbon 
bisulphide with cinnamic acid in solution can be decanted. Add 
another portion of the carbon bisulphide and treat as before. Finally 
pour the tolu solution into a glass tray and evaporate the benzine. 
Place in a 1/2 oz. glass-stoppered phial 1 fluid drachm of naphtha- 
line monobromide, and add gradually about three times its volume of 
the resin of tolu, or sufficient to make the mixture quite stiff when cold. 
The solution will be effected slowly at about 45° C. The above con- 
stitutes a mounting medium which is rather easier to use than Canada 
balsam. 
Warm the medium at 40° to 45° C. until quite fluid, take up a 
minute quantity on a warm needle, place on centre of cover-glass and 
invert on slide. Use no pressure whatever, but warm the slide gently, 
when the medium will flow to edge of cover. 
After a few days ring with a non-alcoholic cement. This method of 
treating balsam tolu does not remove an atom of resin, and does not 
allow an atom of cinnamic acid to remain. 
The subsequent solution in naphthaline monobromide produces a 
medium of higher index (l* 73) than the resin alone, permanent in 
structure and volume, and free from objections to which any medium in 
a volatile solvent is subject.” 
Tolu and Monobromide.* — Mr. H. L. Smith writes to the Editor of 
the c Microscopical Bulletin ’ : — 
“ I meant to reply to your letter before. The bromide medium will 
keep if tightly sealed , but almost all cements, and some coloured waxes, 
decompose it. I must say I am not satisfied, and would not advise any 
one to use it. The yellow medium can be made to keep, but I don’t 
like the colour. 
Mr. Weir, of Norwich, Conn., sent me a compound of monobromide 
of naphthaline and tolu, which is best of any of the high mediums yet — 
no crystals, easy to use, and very satisfactory. 
He is about publishing the formula. I wish somebody — you or 
some one — would make it for sale, as he does not intend to do this. 
It has full as high index as monobromide, and none of its disadvantages. 
It has consistency of ordinary balsam, and is used like that. It can 
be hardened by careful heat; or better, mount without heat, and in a 
day or so it will harden to allow asphalting, or in a few more days 
will need no ring. It is going to do the thing, I guess. 
Nothing could please me more than to have you make the bromide 
medium if I could advise it. It keeps perfectly well in the bottle. I 
have it two and three years old. No decomposition at all, but it acts so 
powerfully on all cements, that this prevents its usefulness. The index 
is considerably above monobromide, but the latter is high enough, and 
I am pretty well pleased with it.” 
Fixing Sections with TJncoagulated Albumen.f — Dr. J. Rabinovicz 
has found that albumen may be used for fixing sections to the slide by 
* Micr. Bull, and Sci. News, vii. (1890) p. 24. 
f Zeitschr. f. Wiss. Mikr., vii. (1890) p. 29. 
