382 General Notes. 
holic borax-carmine (twenty-four hours), transferred to 70 per cent. 
alcohol plus 1 per cent. hydrochloric acid (twenty-four hours), and 
finally placed in pure alcohol. 
or examination, glycerine is preferred to clove oil. If the egg- 
sacks are removed from alcohol to a mixture of glycerine (1 part) 
and absolute alcohol (3 parts), and then allowed to stand until the 
alcohol has evaporated, the eggs do not shrink. It will be found, 
however, that the eggs are not all equally well preserved with the 
cold mixture, owing probably to individual differences in the con- 
stitution of the membranes, some being more, others less, perme- 
able to the fixing reagent. 
AN INEXPENSIVE SECTION-SMOOTHER.—The cut shows a device 
for preventing the curling of paraffine sections, which is extremely 
simple and easily made. After cutting off the head and point of 
an ordinary brass pin, fix it parallel to the edge of the knife by 
pressing its ends into two small pellets of beeswax. The pro 
elevation is easily determined by testing on the waste paraiiine 
before the object is reached. The pin can only be used with the 
transverse knife. With the knife set obliquely, a piece of drawn 
wire will serve the same purpose.—H. C. Bumpus. 
TABLETS FOR ANATOMICAL PREPARATIONS.—Lhe following 
information respecting the materials used for mounting tablets 1m 
the Museum of Comparative Zoology has been furnished by Pro- 
fessor E. L. Mark :— 
For dry objects, various materials haye been used at different 
times: (1) Glass painted on one side; (2) plaster of Paris slabs, 
white or colored ; (3) pasteboard ; (4) wood, thin layers glued, with 
grain running at right angles; (5) slate; (6) cement, The last 
is worthless. Slate is now preferred. 
Samuel Garman was the first to use the plaster tablets for alco- 
holic preparations. In the Annual Report of the Curator for 
1877-8, p. 25, Mr. Garman says: “It is found that by mounting 
the majority of the Sauria and Batrachia on plaster tablets in jars 
of alcohol their value for purposes of exhibition is greatly enhanced. 
This takes considerable labor ; but once mounted, they will need no 
further attention for a long period.” 
Garman used these tablets in his own room as early as 1875, but 
they were not introduced into the exhibition rooms until 1877. 
