RKVIKWS. 
405 
On compnrinp; the results obtained in Dolcoatli in 1821-22 and 1827, it nppears 
that the tc-nipciaturc was increased ouly 4" in one level, with an increased depth 
of 252 feet, giving a ratio between the stations of 1° increase in C3 feet ; and in 
another level the tiiiipeiature was actually 2"lo 2° 5' less than in 1822, although 
252 feet deeper than tlie mine was then. " Tliese experiments," Mr. Fox says, 
'• were made with great care, and thi.s exceptional case may probably be due to 
the greater hnn'ri'-ss and compactness of the loJe in the deeper lev^l and the 
diuiinislied quantity of water." 
The dcptli of Tresavean was increased 540 feet, between 1837 and 1853, and 
the temperature 8° 5' in the deepest level, or in the ratio of 1" in 63-5 feet. 
Mr. Fox has not included in the above tables the recent results in the United 
Mines nor Fowey Consols, the experiments not haviii<r been made in the di^epest 
levels; but the hot spring at 116°, at the depth of 255 fathoms in the United 
Mines, gives a ratio of 1" increase;.in in 2o-2 feet ; and the rock in another level, 
also 255 fathoms deep, 1° in 47 feet. 
In 1853, the botti>m of the United Mines was 275 fathoms, and the rock 94", 
or in the ratio of 1° in 37-5. At Fowey t'onsols, the rock, in a level 288 fathoms 
deep, was 93", or in the j-atio of 1° in 40 2 feet. 
" Widely," continues Mr. Fox, " as the ratios differ from each other in different 
mines and in different parts of the same mine, the results tend to confirm the 
statement that the temperature in general increases less rapidly in deep mines 
than in those which are of inferior de])t!i ; and this is more especially observable 
when experiments are made, from time to time, at the bottom of a mine as the depth 
increases, unless the results be modified by an increase of water coming from 
greater depths. It is not, however, to be inferred that the diminishing ratio of 
temperature in descending into the earth extends to an indefinite depth ; it may, 
on the contrary, and probably does, increase much more uniformly at depths 
where the circulating w.iter has little or no iniiuence." 
" A copious spring of warm water gushing from a vein is hailed by the miners 
as a favourable indic.ition of the proximity of ore, and so is a pervious or 
' hollow ' lode ; but the former ciearly results from the latter, the warm water 
rising through the lode." 
"Sh: Fox then briefly remarks upon the qualities of these subterranean waters, 
and the general absence iu them of saline or mineral matter at their issue ; 
while, on the other hand, it is observed that the water collected in the pools in 
tiie levels frequently contain metallic salts derived from the ore-heaps broken 
from the lodes, and exposed to the joint action of air and water. The phenomena 
observed in mineral veins, however, alibrd strong presumptive evidence that the 
water circulating through them has, from time to time, varied much in its 
properties, sometimes depositing minerals, and at others decomposing them. In 
concluding, Mr. Fox adds that, on. comparing the specific gravities of pieces of 
difl'erent rocks taken from the deepest parts of some of the mines with others of 
the same kind occurring at or near the surface, he has not found any decided 
difference between them in that respect. 
Mr. Fox's paper is marked by a conciseness and precision which render it 
difficult to abbreviate it, and in this abstract we have used his own expressions, and 
have given the details as much length as possible, .as there is not even a really 
superfluous word in the original memoir. 
The I'eport on the Marine Zoology of Strangford Lough, in the Irish (lhannel, 
by Dr. Dickie, is valuable to the geologist as well as the naturalist, as a record of 
the characters of sea-bottom with which certain forms of mollufsca are associated, 
and for the notings of the species to which the broken and dead shells in each 
locality dredged belonged. 
Mr Bowerbank contributes a further report on tlie vitality of the Spong'adse. 
In the former paper by this gentlemen, read at tlie previous meeting, his observa- 
tions on the inhalations and i:xhalation of water through the pores and oscula of the 
British marine s'^ougnllymeniacidon caruncula were recorded, showing the capability 
which that sponge possesses of opening and shutting those tubula cavities at 
pleasure. The present investigations were undertaken to determine the nature 
and power of the imbibing pores, which can only be seen in young and transparent 
