t 
Chemistry and Physics. 393 
molecule of volume, V, of any gas under any constant pressure, p, at any 
temperature, T (Tp =-=278° C. below 0° C.) two calorics (or units of 
heat) are necessary to overcome the external work for each degree C. the 
of course refer to the same unit of weight.—Sitzungsberichte, Wien, 
— lii, 417-452; Corresp. Blatt d. naturf. Vereins, Riga, 1864, xiv, 
5-44; LInstitut, 1866, p. 191. i. 
12. Ex nsion of water below C.—Dr. Wetpner has, by means of 
for — 4° C., where the first series deviates 37 millionths; on referring to 
the formula, the stated value, 513 millionths, is found to be 550°6, agree- 
ing with the other three in the sixth decimal. Taking the mean from 
the four values given by Weidner we obtain the following volumes of 
water, 
Weidner. Despretz. Pierre. 
+ 4° C. 1000000 1000000 1:000000 
+ 3* 14 8 5 
+ 2 “ 40 33 27 
| is 13 
= Of 137 127 118 
ne Bae 210 214 214 
—2* 302 308 817 
= 3 415 422 430 
aR Shs 550 562 556 
= 5 709 699 700 
a 893 918 
exch Ys 1104 1135 1054 
sad as 1344 1378 1271 
vie 1608 1631 1520 
~10°% 1001905 1803 
Above zero Weidner’s volumes are greater; but between 0° and —6° 
the three mb correspond well enough.—Pogg. Ann., 1866, 
ere 300-3 G. H. 
Saws heat of soils ——L. Praunpter has determined the specific 
ry of seventeen soils with great care. The accuracy of the method 
with a modified Regnault’s apparatus, was proved by determining the 
specific heat of water and of Lceland spar. The first showed the same 
terminations on the same piece, successively more and mo divi 
O-2 with a probable error of only 0°00006. ‘This agrees 0208 
nault’s resul 4 (from eighteen Seng empiae a ae Be opps 0 
— four determinations), thus disproving that 
0°202). For soils he fi Fag at gu heat “arti one- in and sae 
if AN 1923 and eaoeby; th ; common value is 0°25 to 0°30. 
Soils free from humus have ‘the ‘siortat specific heat, whether they con- 
