Royal Society : Prof. Faraday* s Researches in Electricity. 4 1 1 



have happened in collieries where the '• Davy lamp" is used, to the 

 ignorance and wilfulness of the workmen, proposes, for the security 

 of the lamp from injury and mismanagement, that the body of it 

 should be formed of a strong spherical glass, furnished with a cop- 

 per tube above and below, and that surfaces of wire gauze should 

 be placed at these points, protected by parallel metallic plates, so as 

 to be inaccessible to the workmen. The glass is defended externally 

 by strong arched wires. It is also provided that the upper and lower 

 parts of the lamp should be connected by means of a spring, so as to 

 permit of a sliding motion, for the purpose of deadening in one di- 

 rection the effect of any shock or concussion. According to this 

 arrangement the air can only enter below the flame and pass up 

 within and through it, and the products of combustion are conducted 

 directly upwards to a proper aperture in the cover of the lamp. 



Professor Graham noticed with regard to safety lamps, on the 

 theory of which he has been some time engaged, that wire gauze is 

 rendered much more impervious to flame by being first dipped in an 

 alkaline solution, which also protects the wire from oxidation. 



On a new Electrometer. By William Snow Harris, F.R.S., <^c. 



Report of the Committee appointed to consider the subject of Chemical 

 Symbols. By Dr. Turner. 



[This Report, with remarks of several of the members of the 

 Committee, will appear in the next volume of the Transactions of 

 the Association.] 



ROYAL SOCIETY. 



June 4% — Professor Faraday's Tenth Series of ft Experimental Re- 

 searches in Electricity, " was read. 



This paper relates altogether to the practical construction and use 

 of the voltaic battery. Guided by the principles developed in former 

 series, the author concluded that in voltaic instruments in which the 

 copper surrounded the zinc, there was no occasion for insulation of 

 the contiguous coppers, provided they did not come into metallic 

 contact^ and therefore in the construction of some new instruments 

 he interposed paper only between the coppers instead of the usual in- 

 sulating plate of porcelain or glass. The battery thus constructed is 

 essentially the same with Dr. Hare's j and the author recommends 

 even his form of trough for the purpose of putting the acid on to, and 

 moving it from the plates. By attending to certain points described, 

 as many as 40 pairs of plates could be packed into a space not more 

 than 15 inches in length, and thus a very portable, and, at the same 

 time, powerful and convenient trough might be obtained. 



In comparing this form of trough with others, the author used acids 

 of constant strength, took note of their quantity, allowed them to 

 act in the troughs until the power of the apparatus had nearlv ceased, 



3 G 2 



