348 Proceedings of the British Association. 



Section G. — Mechanical Science. 



President — Davies Gilbert, Esq. 



Vice Presidents — M. I. Brunei, Esq., John Robison, Esq. 



Secretaries— T. G. Bunt, Esq., G. T. Clark, Esq., William 

 West, Esq. 



The discussions were opened by some observations of Professor 

 Moseley on the theory of locomotive carriages. 



Dr. Lardner next laid before the meeting many details in regard 

 to Railroads. Afterwards Mr. Russell of Edinburgh read an im- 

 portant memoir on the traction of boats in canals at different velo- 

 cities. 



Tuesday, Axigust 23. • 



Section A. — Mathematics and Physical Science. 



Mr. Russell gave an interesting statement of a series of experi- 

 ments regarding the laws of the Motions of Waves excited in 

 Water. 



Prof. Powell read a paper respecting the Refractive Indices of 

 several Substances. 



A paper was then read, contributed by Sir D. Brewster, " On 

 the Polarizing Structure of the CrystaUine Lens of the Eyes of An- 

 imals after Death." 



The Rev. J. W. M'Gauley read an account of "A Series of Ex- 

 periments in Electro-Magnetism, with reference to its application as 

 a Moving Power." 



Section B. — Chemistry and Mineralogy. 



Mr. Exley read a very interesting memoir on a new theory of 

 chemical combination, deduced from mathematical data, and demon- 

 strated mathematically. 



Dr. Charles Henry read an account of some experiments made 

 with a view to determine the mode in which certain gases act in 

 preventing the action of spongy platinum upon a mixture of oxygen 

 and hydrogen. The gases he examined were carbonic oxide and 

 defiant gas. He found that carbonic oxide was the most powerful, 

 and that carbonic acid was always the result. Hence it is evident 

 that oxygen and hydrogen are prevented from combining by the su- 

 perior attraction of the carbonic oxide for the oxygen. Olefiant gas 

 he found not to be decomposed, and hence the attraction which pre- 



