505 



3. That the sources from which the various kinds of 

 malaria arise, are the decomposing animal and vegetable 

 matters which are wholly or partly excluded from the free 

 contact of atmospheric air; and that the kind of decom- 

 position taking place under such circumstances depends on 

 temperature and other causes. 



4. That organic matters, freely exposed to the air and 

 not saturated with water, will not produce compounds of the 

 nature of malaria. 



5. That the conditions necessary to prevent the formation 

 of malaria are (in addition to a free access of atmospheric 

 air) the same as those we should use to prevent putrefaction; 

 and the means used to destroy it would be by the action of 

 oxydizing agents and antiseptics. 



A discussion followed, in which the Chairman, Mr. Hay- 

 wood, Dr. Alexander, the Rev. W. Thorp, and Mr. W. S. 

 Ward took part, and the obligations of the Society were 

 expressed to Mr. Haywood for his valuable and opportune 

 paper. 



A Paper was then read — 



ON A MECHANICAL COMMUNICATION FOR THE WORKING 

 OF SIGNALS AND BREAKS ON RAILWAYS. BY WILLIA.M 

 SYKES WARD, ESQ., OF LEEDS. 



Much attention has lately been paid to the effecting a 

 communication between the engine drivers of railway trains 

 and the guards in charge of the carriages ; and also to 

 provide means of communication between the passengers 

 and the guards or engine drivers ; but no method has yet 

 been suggested so unobjectionable as to meet with general 

 encouragement or support. 



The directors of railways object to the expense of making 



