23 ELECTRIC LIGHTING. 



liquid, and is then withdrawn completely amalgamated, and 

 with i litre of the liquid 150 zincs may be amalgamated. 



The zincs are also amalgamated by plunging them into a 

 vessel filled with water acidulated with hydrochloric acid 

 into which some mercury has been poured, and by rubbing 

 them with a metallic brush dipped into mercury. But it is 

 best to use zincs amalgamated throughout their whole mass. 

 Dronier has succeeded in forming zincs of this kind by 

 uniting mercury to the zinc during its fusion in a closed 

 vessel. 



Tommasi has recently arranged Bunsen's cell in such a 

 manner as to produce the electric light under relatively good 

 conditions. According to an article published by Moigno 

 in Les Mondes of the 24 Juillet, 1879, Tommasi has even 

 succeeded in making this battery inodorous by hermetically 

 closing the porous vessels containing the nitric acid. The 

 upper part of these vessels is enamelled, and serves as a 

 reservoir for a certain quantity of the liquid that is periodi- 

 cally renewed by means of an opening which is again closed 

 up, and a combination of syphons to maintain the contents 

 of the outer vessels at the same level. An upper vessel 

 containing a part of the acidulated water permits it con- 

 stantly to flow in small quantity into the first of the outer 

 vessels, distributes it by the syphons to all the cells of the 

 battery up to the last, and this discharges its overflow into a 

 vessel which leads it into a waste-pipe. The zincs stand in a 

 small circular trough placed in the acidulated water, and 

 containing mercury to keep up the amalgamation. 



"After three months of constant experiments and observa- 

 tions," says Moigno, " we have been able to ascertain that the 

 expenditure of the battery for a lamp by incandescence is about 

 i litre of nitric acid and 2 litres of acidulated water a day, 

 and the expenditure of the lamps is from 15 to 20 centimetres of 

 carbon per hour." 



We must add that this arrangement of the battery is nothing 

 very novel, and we have described several systems of this 



