234 THE AMERICAN MONTHLY [Aug 
more serviceable for the nervous systém and for vegeta- 
ble sections. I find it, however, the most convenient stain 
to use for celloidin sections. Some of the sections would 
have been: improved by a little longer treatment with 
acid alcohol. In my opinion there is no better stain ‘for 
animal tissues than haematoxylin, and especially Ehrlich’s 
ammoniated haematoxylin. I would rather part with all 
the other microscopical staius than this. I would suggest 
the use of this stain for animal sections in preference to 
carmine, together with eosin asa contrast stain. Carmine 
and haematoxylin are nuclear stains; picric acid isa 
plasmatic stain and cannot supplant a nuclear stain like 
carmine, but may be used after it or in conjunction with 
it, as in the well-known picro-carmine stain. The only 
disadvantage raised against haematoxylin as a stain is 
that it is thought not to be permanent. This may be the 
case with some preparations, but I have not found it to be 
so with Ehrlich’s. The aniline stains, though permanent 
and capable when skilfully used of giving very fine 
results, and also of being very useful for special purposes, 
require care in their use, and are not very suitable to be 
put into the hands of a beginner. Further, they are 
quite unsuitable for celloidin preparations. I have used 
picric acid in conjunction with aniline blue as a nuclear 
stain, but the differentiation is not so sharp and the re- 
sult not so good as that obtained by heomatoxyli# and 
eosin. —J. R. L. Dixon. 
I have seen some very good’ slides prepared in Germany 
by injecting the-the blood-vessels with a solution of 
gelatin colored, I believe, with cochineal. I have had 
some of the slides more than twenty years, and the color 
is good now as at the first. The condition of the epithe- 
lium of a mucous membrane can be readily seen, and this 
is important in some diseases.— F’. Bossey. | 
The picro-carmine staining slides of the same tissue are 
interesting if put up with: (a) Picro-carmine and Far- 
a Pe a . = 
os oe 
