[71] _On the Effect of Heat in lessening the affinities of the Elements of Water_: by the Rev. Thomas Romney Robinson, D.D.--Transactions of the Royal Irish Academy, vol. xxi. part 2. [72] _An Inquiry concerning the Chemical Properties that have been attributed to Light_: by Benjamin, Count of Rumford.--Philosophical Transactions, vol. lxxxviii. p. 449.--The results obtained by Count Rumford were probably due to the non-luminous heat-rays--parathermic rays--which are known to be given off by boiling water. [73] For Dr. Drapers paper, see Philosophical Magazine for May, 1847, vol. xxx. 3rd series. [74] _On the Action of the Rays of the Solar Spectrum on Vegetable Colours_: by Sir J. F. W. Herschel, Bart. The proof of the continuation of the visible prismatic spectrum beyond the extreme violet may be witnessed in the following manner:--“Paper stained with tincture of turmeric is of a yellow colour; and, in consequence, the spectrum thrown in it, if exposed in open daylight, is considerably affected in its apparent colours, the blue portion appearing violet, and the violet very pale and faint; but beyond the region occupied by the violet rays, is distinctly to be seen a faint prolongation of the spectrum, terminated laterally, like the rest of it, by straight and sharp outlines, and which, in this case, affects the eye with the sensation of a pale yellow colour.”--Philosophical Transactions, p. 133. [75] The most complete exposition of the theory that animal heat is derived from chemical action only, will be found in _Animal Chemistry, or Chemistry in its applications to Physiology and Pathology_, by Justus Liebig: translated by Dr. Gregory. The conclusions arrived at by the author, notwithstanding his high--and deservedly high--position in chemical science, must, however, be received with great caution, many of them being founded on most incorrect premises, and his generalizations being of the most hasty and imperfect character. At page 22 the following passage occurs:--“If we were to go naked, like certain savage tribes, or if in hunting or fishing we were exposed to the same degree of cold as the Samoiedes, we should be able, with ease, to consume ten pounds of flesh, and, perhaps, a dozen of tallow candles into the bargain, daily, as warmly clad travellers have related with astonishment of these people. We should then also be able to take the same quantity of brandy or train-oil without bad effects, because the carbon and hydrogen of these substances would only suffice to keep up the equilibrium between the external temperature and that of our bodies.” A brief examination will exhibit the error of this. The analysis of Beef, by D. Lyon Playfair, is as follows:-- Carbon 51·83 Hydrogen 7·57 Nitrogen 15·01 Oxygen 21·37 Ashes 4·23 And the following has been given by Chevreul as the composition of mutton tallow:-- Carbon 96 Hydrogen 16 Nitrogen 16 Oxygen 48