304 Scientific Intelligence. 
dron.” ‘In speaking of the areoles, I take it for granted that 
the curvature of the cast represents that of the stem.” “The 
specimen may, however, have been a bit of bark pressed out 
of shape.” 
My own opinion, after a careful examination of the original, 
is that the curvature of the cast does represent that of the stem, 
and consequently that Dr. Dawson’s remarks on its resemblances 
are wellfounded. The bark of Lepidodendra, etc., when pressed 
as usually occurs in the Coal-measures, is constantly flattened. 
In a subsequent communication, Dr. Dawson alludes to the 
possibility suggested above, that the fossil may exhibit a com- 
posite character partaking of the character of more than one 
existing genus. The wide diffusion of the type which it most 
resembles in the Lower Carboniferous is good reason for be- 
lieving that it is very ancient, and therefore its occurrence so low 
as the Clinton limestone is the less surprising. 
In conclusion, I gladly express my indebtedness to Dr. J. W 
Dawson, of Montreal, for valuable aid cheerfully rendered, and 
Mr. Leo Lesquereux, of Columbus, in this State, for prompt 
and kind replies to letters of enquiry. 
SCIENTIFIC INTELLIGENCE. 
I. CHEMISTRY AND PHYsICcs. 2 
1. On certain Fundamental Thermo-chemical Data.—BERvHE- 
Lot has re-determined with great care the heat data belonging to 
certain chemical reactions, using an improved calorimeter for the 
purpose, described in the memoir. The heat of formation of 
sulphurous oxide, although determined many times, was not UP 
to this time accurately known. Thus sixteen grams of sulphur 
burned to gaseous sulphurous oxide gave Dulong 41°6 calories, 
Hess 41-1, Andrews 36°9, and Favre and Silbermann 35°6, the 
. 
glass, and the sulphur used the octahedral variety. The mean 
result was, for sixteen oe of sulphur, 34°55 calories. From 
lates the heat of formation of sulphuri¢ 
diamond, in burning to C,O, evolves 94, C, in burning to C,0, 
evolves 94 —68 2=25°8, or for amorphous carbon 28°8. Ethy lene 
twenty-eight grams, yields 334-5 calories, acetylene twenty-5!* 
