Chemical Notices. 107 



veiled over water than when it has travelled over land, — show- 

 ing that the object was more distant than would be given by a 

 calculation with the velocity of sound ordinarily used. This is 

 explained by the velocity being slightly greater over still water 

 than over the rough surface of the land ; and we know that sounds 

 are heard much further over still water than over land. The 

 artillery solution of the fact, that " the water attracts the shot' 3 

 we may leave to their own system of natural philosophy. 



The challenge which I gave in my paper "On Hydrody- 

 namics" in the Philosophical Magazine for March 1851, that 

 the properties of diverging streams of air in Roberts's experi- 

 ment (often called Clement's experiment), described in the fifth 

 volume of the new series of the Transactions of the Literary and 

 Philosophical Society of Manchester, could not be solved by the 

 received equations for fluid motion, has never been answered; 

 nor has any valid solution, except my own based on atomic con- 

 siderations, been published that I am aware of. If any method 

 of treating hydrodynamics fails to solve so simple a problem, it 

 has no claims to our respect. 



As to the mutual support which the theory of sound and the 

 mechanical theory of heat afford to each other, as stated by Dr. 

 Le Conte, the less that is said about it the better, whilst the 

 objection*, "His method of calculating the specific heat of 

 gases, from the mechanical effects which they produce, leads to 

 results which materially differ from those obtained by the ob- 

 servations of De la Roche and Berard," and, we may add, now 

 from those obtained by M. Regnault also, is unanswered. 



XXI. Chemical Notices from Foreign Journals. 



By E. Atkinson, Ph.D., F.C.S. 



[Continued from vol. xxvi. p. 542.] 



ZWENGER and Bodenbender have contributed the results of 

 an investigation on cumarinef. It had already been ob- 

 served that the accounts given of the properties of this substance 

 differ with its source, and so considerably that the bodies cannot 

 be identical. They investigated first of all the cumarine from Me- 

 lilotus. The aqueous extract of this substance is treated with ether 

 until the solution has scarcely an acid reaction, and then the ether 

 is removed by distillation. A greenish, partly slimy and partly 

 crystalline mass is left, which dissolves by repeated treatment 

 with boiling water, with the exception of a small residue. On 



* Annual Report of the Progress of Chemistry and the Allied Sciences, 

 by Professors Leibig and Kopp. The translation by Drs. Ilofmann and 

 Bence Jones. Vol. hi., for 1849, p. 20. 



t Liebig's Annalen, June 1863. 



