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H. Goadby on making wet Preparationsof Animal Subst 233 
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of contraction of the A fluid. I then as gradually increased 
the temperature to 100° and noted the expansion of the fluid. 
I went through a similar course of proceeding with the A2 
and the B fluids respectively, always taking 60° as the mean, 
and 100° and zero as the maximum and minimum temper- 
atures, i 
From these experiments I deduced the following: in all the 
fluids the contraction was not equal to the expansion; neither 
were the results similar with any two fluids; that, the expan- 
sion was in direct ratio to the density of the fluid; thus, it is 
preparation. ‘The experiment with the A2 fluid induced me to 
think that the expansion and contraction of the glass agreed very 
nearly, or quite, it might be, with the fluid; and that the marine 
glue and black cement fully sympathized. I took, therefore, a 
sound preparation contained in a large cell, the top cemented 
with the black cement, and placed it in the water at 60°, an 
from this point I continued the experiment down to zero, up to 
100° as before described, and continued to do this alternately for 
hearly two hours—to this time it has not undergone any change. 
have sometimes been asked, “what provision I made against 
freezing of the fluid ;” no provision is necessary, as it cannot 
freeze. A fluid of the specific gravity, therefore, of the A2 fluid, 
may be regarded as the maximum density that can weather the 
temperature of the atmosphere through all its phases, and the 
knowledge of this fact makes me fear for the permanency of 
valuable preparations by my hand, preserved in the denser fluids 
and now in. Europe. 
Another fact has resulted, that if a preparation be well and 
thoroughly preserved in either of the fluids before described, and 
Which may be best adapted to the particular animal, it may. 
sealed down hermetically without air in a fluid of less specific 
8tavity, and it will be permanent. i . 
"he square glass boxes are eminently calculated to give the 
best effects, as preparations, to a vast number of the invertebrate 
animals. If a bottle be used, no matter what its shape, the ope- 
rator has no alternative, but must suspend his specimen from the 
top, whether it be an ani hose natural habitat is the bottom 
of the ocean fixed firmly to a solid rock or otherwise, there it 
Szconp Sexzes, Vol. XIII, No. 38—March, 1852. oa Lees ee 
