Transactions of the Royal Society of Tdinhurgh. 31(1 
13. On a New Species of Double Refraction^ accompanying a 
remarlmhle Structure m the Mineral called Analeime. By 
David Brewster, LL.D. F.R.S. Lond. & Sec. R. S. Ed. 
—187--194. 
An abstract of this paper is already given in this Number, 
p. 255. 
14. On the Specific Heat of the Gases, By W. T. Hayciiaft^ 
Esq.—P. 195-216. 
The experiments contained in this paper seem to have been 
conducted with great care, and great attention to accuracy, in. 
every particular The results which they seem to authorise^ 
are, that all the gases examined, viz. oxygen, hydrogen, car- 
bonic acid, azote, and carburetted hydrogen^ have all their spe- 
cific heats in the mean proportion of their specific gravities ; that 
different states of combination of the gases with aqueous and 
other vapour j affect the capacities of the gases, and that proba- 
bly, in some instances, in a regular arithmetical progression, cor- 
responding with the arithmetical rate of expansive force of the 
gases, in different states of combination with vapour The 
most interesting result to the physiologist is, that the air from 
the lungs has a less specific heat than atmospheric air, at a tem- 
perature of between 100 and 95°. The air of respiration, at a 
temperature of 102® and upwards, and of 91° and downwards^ 
had the same capacity as atmospheric air. 
15. On the Forms of Crystallisation of the Mineral called the 
Sidphato-tri-Carbonate of Lead. By W. Haidinger, Esq. 
F.R.S.E.^P. 217-230. 
An abstract of this paper is already given in this Number of 
the Journal. Independent of the rnineralogical results which 
are given in this elaborate examination of the Sulphato-tri-Car- 
bonate of Lead, it establishes, beyond a doubt, the accuracy of 
Dr Brewster’s law relative to the connection between the pri- 
mitive forms of minerals, and the number of their axes of double 
refraction, which Mr Brooke had called in question from an im- 
perfect examination of the sulphato-tri-carbonate of lead. 
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