

Oscillation- 



Density. 



period. 



1 



1 



16 



0-5704 



14 



0-5860 



14-438 



0-5825 



Dr. VV. Ramsay on Picoline and its Derivatives. 269 



On the basis of this equation the following Table was calcu- 

 lated : — 



Name of the gas. 

 Hydrogen . . . 

 Oxygen . . . 

 Nitrogen . 

 Atmospheric air . 



From this Table it is seen that the denser gas pulsates more 

 quickly, the less dense more slowly ; the duration of an oscil- 

 lation is nearly twice as great for hydrogen as for oxygen. 



Only one brief remark more. If it is true, as we have rea- 

 sons for assuming, that in nature, on account of imperfect 

 elasticity, friction, viscosity, and the radiation of energy, re- 

 versible cyclical processes cannot actually take place, that con- 

 sequently 



k 



is ever greater than nil, then must also 



be always greater than nil. In other words, the function 



A=2iT, 



which Maupertius named " action," is (with respect to the 

 source of the energy received) absolutely less in amount at 

 the end of each variation than at its commencement. Hence 

 the hypothetic proposition, that the entropy of the universe is 

 always increasing (Clausius), can also be expressed thus : — 

 The action of the universe is continually diminishing. 



XXXIY. On Picoline and its Derivatives. By William Ram- 

 say, Ph.D., Tutorial Assistant of Chemistry in the Glasgow 

 University *. 



BASES of the pyridine series have been formed in a num- 

 ber of different ways. Perkin (Journ. Chem. Soc. [2] 

 vol. iii. p. 173) prepared pyridine by reducing azodrftiaphthyl- 

 diamine with tin and hydrochloric acid. It was found as a 

 constant product along with naphthendiamine and naphthyl- 

 amine, but only in small quantity. As pyridine has a formula 

 exactly half of that of naphthendiamine, C 10 H 10 N 2 , it is pos- 

 sible that the latter splits up into two molecules of pyridine. 

 But Perkin was unsuccessful in preparing naphthendiamine 

 from pyridine. 



* Communicated bv the Author. 



