xliii 



garding their ventilation. He inspected the dioptric light of the first order, 

 which had just been constructed in France and put up by French work- 

 men, and compared its consumption of oil with the 15 Argand burners which 

 were previously in use. 



He sent to the Philosophical Magazine a paper on Static Electrical Induc- 

 tive Action. Among his notes the following occurs : — " Propose to send to 

 the Phil. Mag. for consideration the subject of a bar, or circular, or spherical 

 magnet — first, in the strong magnetic field; then charged by it; and, finally, 

 taken away and placed in space. Inquire the disposition of the dual force, the 

 open or the related powers of the poles externally, and if they can exist un- 

 related. The difference between the state of the power, when related and 

 when not, consistent with the conservation of force. Avoid any particular 

 language. Should not pledge myself to answer any particular observations, 

 or to any one, against open consideration of the subject. Want to direct 

 the thoughts of all upon the subject, and to tie it there ; and especially to 

 gather for myself thought on the point of relation or non-relation of the 

 antithetical force or polarities." 



He was made Honorary Member of the Literary and Philosophical Society 

 of Manchester, and Useful Knowledge Society, Aix la Chapelle. 



JEt. 52 (1844). 



He communicated to the Royal Society a paper on the Liquefaction and 

 Solidification of Bodies generally existing as Gases. His object was to sub- 

 ject the gases to considerable pressure, with considerable depression of 

 temperature. Though he did not condense oxygen, hydrogen, or nitrogen, 

 the original objects of his pursuit, he added six substances, usually gaseous, 

 to the list of those that could previously be shown in the liquid state, and 

 he reduced seven, including ammonia, nitrous oxide, and sulphuretted hy- 

 drogen, into the solid form. 



He sent to the Philosophical Magazine a speculation touching electric 

 conduction and the nature of matter. Elsewhere he calls this (< a speculation 

 respecting that view of the nature of matter which considers its ultimate 

 atoms as centres of force, and not as so many little bodies surrounded by 

 forces, the bodies being considered in the abstract as independent of the 

 forces, and capable of existing without them. In the latter view these 

 little particles have a definite form and a certain limited size. In the former 

 view such is not the case ; for that which represents size may be considered as 

 extending to any distance to which the lines of force of the particle extend. 

 The particle, indeed, is supposed to exist only by these forces, and where 

 they are it is." 



This was the subject of his first Friday discourse. He also gave the 

 last discourse on recent improvements in the Manufacture and Silvering of 

 Mirrors. 



For the Trinity House he only examined different cottons for the 

 lamps. 



