478 
illustration, the cover and the dish will 
each bear the same number cut} in glass, so 
that the student, working at his desk, may 
easily avoid mixing the covers which would 
not only be detrimental by mixing incom- 
patible fluids; but, as each lid can be ground 
only to fit the dish which accompanies it, 
exchanged lids will not fit tightly. 
In order to facilitate cleaning and to 
avoid inaccessible corners, all the corners 
are rounded. 
Yr 
curs oS 
Fig. 1.—This cut is about # of the exact size of 
the dish. At A can be seen ten (10) slides, placed 
back to back and passing down between the ribs at B. 
Since this figure was drawn the width of the base has 
been increased, so that the base is now the width as 
shown in Fig. 2. 
The advantages claimed for the dish are: 
(1) Convenience, in that a number of 
slides can be safely handled at one time. 
(2) Great economy in the reagents; not 
only is the amount used less than is re- 
quired by the use of Stender dishes, but in 
SCIENCE. 
[N. 8. Von. VI. No. 143, 
ease, aS will not uncommonly happen with 
students, anything occurs which ruins the 
contained fluid the loss may be materially 
less. (8) Solidity: no other dish of the 
same height and the same capacity possess 
the same solidity. (4) Contained fluids. 
are prevented from evaporating by the 
tight-fitting top. This is not secured in the 
Naples dish. 
ZZ 
= 
Fic. 2.—This represents a transverse section of the 
dish at the point marked B in Fig. 1. In this view 
we are looking down into the dish from above ; the 
ribsand the intervening grooves areshown. The two 
arrows mark the position in which the ribs are lying 
and the two points, between which it is exactly 1 inch. 
Just to the left of the arrow is shown a transverse sec- 
tion of two slides placed back to back, as is usually 
done for staining. 
I desire to express my appreciation of 
the help given me by Messrs. Queen & Co. 
in securing working drawings from which 
the above cuts have been made. 
W. M. L. Coprin. 
JEFFERSON MEDICAL COLLEGE. 
NOTES ON INORGANIC CHEMISTRY. 
THE address of Professor William Ram- 
say, President of the Chemical Section of 
the British Association at Toronto, was out 
of the usual order. It was entitled ‘An 
