OF MICROSCOPIC OBJECTS. 125 
per) a small piece of camphor. This requires no cell, as the 
adhesive power is sufficient. 
Derane’s CompounpD.—This is usually deemed about the 
best medium for preserving Alga, mosses, &c., and is thus 
prepared :—Soak 1 oz. of best gelatine in 4 oz. of water 
until the gelatine becomes soft, when 5 oz. of honey heated 
to boiling point are added; boil the mixture, and when it 
has eooled, but not enough to become stiff, add 4 oz. recti- 
fied spirit with which 5 or 6 drops of creosote have been 
well mixed, and filter the whole through fine flannel. This 
compound when cold forms a stiff jelly, the use of which 
will be described elsewhere. 
GLYCERINE JELLY.—This mixture closely resembles the 
above, but as the composition differs a little it may be men- 
tioned here. It is strongly recommended by Mr. Lawrance 
in the Microscopic Journal, where he states “that the 
beautiful green of some mosses mounted two years ago, is still 
as fresh as on the day they were gathered ;” and that this 
is the only medium he knows which will preserve the natural 
colour of vegetable substances. He takes a quantity of 
Nelson’s gelatine, soaks it for two or three hours in cold 
water, pours off the superfluous water, and heats the soaked 
gelatine until melted. To each fluid ounce of the gelatine, 
whilst it is fluid but cool, he adds a fluid drachm of the 
white of an ege. He then boils this until the albumen 
coagulates and the gelatine is quite clear, when it is to be 
filtered through fine flannel, and to each ounce of the clari- 
fied solution add 6 drachms of a mixture composed one part 
ot glycerine to two parts of camphor-water. 
At the Academy of Natural Sciences of Philadelphia, 
Mr. W. H. Walmsley stated, that, owing to the heat of that 
climate, the above formula for glycerine jelly was not satis- 
factory, and recommended the following :—Take one pack- 
age of Cox’s gelatine, wash repeatedly in cold water; allow 
it to soak in water sufficient to cover it for an hour or two, 
add one pint of boiling water, and boil ten or fifteen 
minutes. Remove, and when cool but still fluid, add the 
