482 



So also silicated fluate of ammonia, or fluoborate of ammonia, "when 

 acted upon by chlorine, yield no silica, or boracic acid, unless in con- 

 sequence of the presence of moisture ; but they form muriate of 

 ammonia, and either silicated fluoric or fluoboric gas. 



When charcoal was ignited in either of these gases no decompo- 

 sition was effected, but only a disengagement of a little inflammable 

 gas from the charcoal. Neither was liquid fluoric acid decomposed 

 by charcoal heated to whiteness in a tube of platina. 



According to the author's experiments on the decomposition of 

 fluor spar by sulphuric acid, the sulphate of lime which remains 

 after complete decomposition weighs more than the spar decomposed 

 in the proportion of 175 to 100. But in order to obtain this result, 

 it is necessary to collect the very purest white Derbyshire fluor, and 

 to distil repeatedly to dryness, after the addition of fresh acid at each 

 repetition. By computing upon the eighth result, and supposing the 

 number representing calcium to be 40, that for fluorine is estimated 

 to be 34-2. 



By forming fluate of potash from a known quantity of subcarbonate, 

 the number obtained for fluorine appeared to be about 32*6. 



From these experiments, and others made on the quantity of fluate 

 of potash obtained from hydrate of potash, the author infers that the 

 number representing fluorine may be estimated at about 33. 



Two cubical inches of ammoniacal gas, weighing 36 grains, were 

 found to combine with one of silicated fluoric gas, which were found 

 to weigh 110'7, the number for which is thence inferred to be 98'4 ; 

 and it is presumed to consist of two parts fluorine, and one of silicious 

 basis. 



The author has made many experiments with the hope of deter- 

 mining the quantity of oxygen in silica, but has not succeeded to his 

 satisfaction. However, since one part of silica requires more than 

 three times its weight of potassium to decompose it, this seems to 

 show that silica cannot contain much less than half its weight of 

 oxygen. But he has not been able to obtain its basis in a separate 

 state so as to ascertain its exact nature. 



Sir Humphry Davy has at various times made many experiments 

 to endeavour to detect oxygen in chlorine, in conformity to the 

 opinion still maintained by many persons, that this is one of its 

 elements, but without success. Sulphuret of lead when acted upon 

 by chlorine, gave the muriates of sulphur and of lead, and not sulphate 

 of lead, as might possibly be expected. Neither is muriate of lead 

 decomposed by sulphureous acid gas, which might be expected to 

 take oxygen if any were present. 



It appears, on the whole, to the author impossible to give stronger 

 evidence of chlorine being undecompounded. In his estimation it 

 ranks with gold, silver, hydrogen, or oxygen. He admits that per- 

 sons may doubt whether these are elements, but thinks it not philo- 

 sophical to doubt whether it has yet been decompounded. 



In reply to some arguments lately advanced by Professor Berzelius 

 in favour of the presence of oxygen in chlorine, deduced from the 



