M l)r. Stenliouse^w the Action of Bromine 



velocity of the orbit being always proportional to that of the 

 body at the same instant; and the eccentricity of the orbit 

 might be any whatever, and would not at all depend on the dis- 

 turbing force. 



Now, since the orbit would be fixed, were it not for the dis- 

 turbing force, it might be argued in exactly the same manner as 

 is done by Professor Challis in the passage above referred to, 

 that the eccentricity of the orbit tnust be a function of the force 

 which causes the orbit to revolve, but this we know to be a false 

 conclusion. 



WTiat would depend on the disturbing force in this case, would 

 be, not the total amount of the fluctuation of distance in different 

 revolutions, but the number of revolutions of the body in which 

 such fluctuation would take place, or the time of revolution of the 

 apse. If the disturbing force were increased, the total fluctua- 

 tion in the value of the radius-vector in question would be the 

 same as before, but the change from one of the extreme values 

 to the other would occupy a shorter time. 



The objection mentioned by Professor Challis at the top of 

 page 283, is alone quite fatal to the supposition that the eccen- 

 tricity of the moon's orbit must have a particular value. Where 

 is the proof that the eccentricity would settle down to such a 

 value, as Professor Challis imagines, if it were initially different ? 



In fact, it is easy to show, by the method of variation of 

 elements, that there would be no such settlement, but that the 

 non-periodic part of the eccentricity would remain constant. 

 I have the honour to be. Gentlemen, 



Your obedient Servant, 



Pembroke College, Cambridge, J. C. Adams. 



June 20, 1854. 



VI. On the Action of Bromine on Nitropicric Acid, !) 

 Bij John Stenhouse, LL.D., F.R.S."^ M 



IT is stated, on the authority of Marchand, at p. 683 in the 

 5th volume of Gmelin's Handbook of Chemistry, that bro- 

 mine has no action on nitropicric acid. As this assertion 

 appeared to me highly improbable on several grounds, I was 

 induced to undertake the following series of experiments. The 

 nitropicric acid on which I operated was made by treating the 

 resin of the Xanthorrhoea hastilis (the yellow gum-resin of 

 Australia) with nitric acid. The resin, which costs only from 

 fourpence to sixpence per pound, yields nearly half its weight of 



* Commimicated by the Author. 



