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2. Some Miscellaneous Observations on the Tadpole, and on 
the Albumen of the Newly-laid Egg. By John Davy, M.D., 
F.R.S. Lond. and Edin. 
On the Tadpole of the Frog . — The author first notices the jelly — - 
the peculiar enveloping matter of the ova — describing its proper- 
ties and uses, — the latter, according to him, for the double purpose 
of defending the eggs before being hatched, and affording the tad- 
poles food after their hatching. He considers the substance of the 
jelly a variety of albumen. 
Secondly , He notices the ova, which he describes as resembling, in 
their properties and composition, those of fishes. 
Thirdly , He enters into some details respecting the growth of the 
tadpole and its metamorphosis, specially dwelling on the fact, that 
whilst in the change to the advanced form there is a diminution of 
volume, there is an increase of solid matter-— the young frog having 
a bony skeleton, which the tadpole is destitute of. 
Fourthly , Experiments are given showing the effect of different 
degrees of temperature on the tadpole, and that of salt water of 
different degrees of saltness. From the last it would appear that 
even brackish water is fatal to them, thus limiting the habitat of 
the species ; from the former, that a temperature exceeding 98° or 
100° has the same effect ; whilst one a little lower seems to promote 
a torpid state, such as the alligator is said to acquire during the 
season of tropical heat and drought. 
On the Albumen of the Newly-laid Egg of the Common Fowl.— 
From the experiments described, it would appear that the albu- 
men of the newly-laid egg differs from that of the egg kept for 
some time: 1st, In becoming milky at about 150° Fahr., owing to 
the formation of innumerable granules, so small as barely to be seen 
with the microscope, — a quality which may be preserved for a con- 
siderable time by the exclusion of oxygen, effected by lubricating 
the shell with oil or butter; 2dly, In forming, at a higher tempera- 
ture, a softer coagulum. 
7 O 
3. On Acupressure, a New Method of Arresting Haemorrhage. 
By Professor Simpson. 
Professor Simpson made a communication on acupressure, as a 
new mode of arresting surgical haemorrhage. After describing the 
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