of Simple Bodies, according to Thomson and Berzelius. 165 



There is an evident oversight here ; and we can only reconcile 

 fluoboric acid to the fluorine theory, by supposing it analogous 

 to phosgene gas. If the oxygen theory be adopted, the base 

 of fluoric acid will of course weigh two less than " fluorine." 



(i.) Glucinum : subject to similar observations with alu- 

 minum (Note a.). 



(k.) Mercury. — I have, on a former occasion*, offered some 

 reasons for conceiving the black oxide and calomel a suboxide 

 and subchloride of mercury ; and consequently that the atom 

 of metal is only half the weight assigned by Thomson. My 

 reasons are shortly these : The red oxide is formed floating on 

 the mercury, in calcination per se ; the same oxide is produced 

 by boiling mercury with sulphuric acid, in which process sul- 

 phurous acid gas is given off"; and water decomposes the salts 

 of this oxide, precipitating a portion of it, unless there be an 

 atom of acid for every 12*5 parts of mercury. Solution of cor- 

 rosive sublimate produces no effervescence with solution of 

 carbonate of soda, though mixed boiling hot ; nor, mixed in 

 solution with oxalate of soda, evaporated to dryness, and 

 subjected to distilled water, does it affect turmeric or litmus 

 paper, unless the sublimate be in excess. And the most inti- 

 mate combination of mercury with sulphur is cinnabar, com- 

 posed of mercury 12*5, sulphur 2. 12*5 may not be the pre- 

 cise number, though I think nearer than that of Berzelius. 

 12*55 (Wollaston's number) is preferred. 



{I.) Nickel. — See note on Cobalt. 



(m.) Phosphorus. — The experiments of Dumas, corrobo- 

 rated by Buss {Ann. Ch. xli. 220), show that phosphuretted 

 hydrogen contains 150 hydrogen in 100 cubic inches ; and 

 requires 200 oxygen to produce water and phosphoric acid. 



150 of hydrogen consume 75 of oxygen; and the remain- 

 ing 125, weighing 42*36 grs., require (from Berzelius's syn- 

 thesis, phosphorus 100, oxygen 128; on a larger scale than 

 Davy's) 33*1 of phosphorus; which must have been present 

 in the gas. The condensation of the hydrogen, analogous to 

 that in ammonia, would indicate the atomic proportion 3:1; 

 and in that case the 125 oxygen ( = to 250 hydrogen) will be 

 5:1. The atomic weight of phosphorus will then turn out 



("150 cub. in. of hydrogen weigh 3*177 grs. 

 From the J The combined phosphorus was 



hydrogen j found to be 33*1 



LAnd-^r^:33*l :: 0*125: .... 3*9 atom ofphos. 

 f 125 cub. in. of oxygen weigh 42.36 grs. 



From the<( The phosphorus 33*1 



oxygen ^And -^^- : 30*1 : : 1 3*9 atom ofphos. 



* See Phil. Mag. and Annals, N.S. vol. vi. p. 167.— Edit. 



Then 



