244 Mr. B. C. Brodie on Myricine. 



thesis of the problem is at fault; that it is not allowable to 

 make the supposition of plane-waves. 



Mr. Airy's views, as I have said, are not borne out by any 

 experiment. On the contrary, an experiment may be adduced 

 which contradicts them. The possibility of hearing distinctly 

 words spoken at a distance, depends on the faithfulness with 

 which the air transmits the impressions made on it by the organs 

 of voice. As the difference between the sound of one letter and 

 that of another corresponds to a difference in the form of the 

 curve representing the succession and magnitudes of the con- 

 densations impressed, it is necessary that that form should 

 remain unchanged by distance of transmission in order that 

 words heard at different distances may be the same sounds. 

 The law of transmission expressed by the formula a + iy, which 

 is the basis of Mr. Airy's speculations, is opposed to this 

 constancy of form. M. Biot, however, has recorded an ex- 

 periment made at Paris, according to which, words pro- 

 nounced at one end of a cylindrical tube SI 20 feet in length, 

 were perfectly distinct at the other end. 



Cambridge Observatory, 

 August 22, 1849. 



XXX III. An Investigation on the Chemical Nature of Wax. 

 By Benjamin Collins Brodie, Esq.* 

 [Continued from vol. xxxiii. p. 391 .] 

 Ill.f On Myricine. 



I HAVE placed the investigation of the Chinese wax be- 

 tween that of the cerotic acid and of the residue of the 

 bees'-wax which remains after that substance has been sepa- 

 rated from it. By the saponification of this Chinese wax we 

 procure, as I have shown, an acid identical with the cerotic 

 acid from bees'-wax, and also the alcohol of this acid, so that 

 the chemical history of these substances is closely connected. 

 We have moreover in the Chinese wax to deal with a sub- 

 stance found in nature in a state of great purity, the products 

 of the decomposition of which by alkalies and by heat can 

 readily be prepared and examined. The knowledge of the 

 relation of these products to one another throws great light 

 upon the nature of myricine, which is not a pure substance, 

 and the chemical relations of which are complex. 



I have stated that the first extracts of wax with alcohol give 

 with acetate of lead an abundant precipitate in a hot alcoholic 



* From the Philosophical Transactions for 1849, part i. j having been 

 received by the Royal Society May 11, and read November 23, 1848. 



t Part I. was inserted in vol. xxxiii. p. 217, and Part II. at p. 378 of the 

 same volume of this Journal. — Ed. 



