50 



COMBINATIONS OF OXIMURIATIC ACID AND METALSr 



peroxide, and the former the protoxide, it is natural to in- 

 fer, that the proportion of muriatic acid is similar in both. 

 But the proportion of muriatic acid in the Submuriate of 

 copper is apparently half of that which exists in the muriate ; 

 hence, supposing the composition of the submuriate of tia 

 to be similar, 100 of it will consist of 



70*4 gray oxide 

 lO'O muriatic acid 

 IQ'6 water 



100- 



Probability alone can be attaclied to this estimate. I have 

 not given tlie calculations by which it was made, as their data; 

 are liable to objection. 



3. On the Combinations of Iron and Chlorine* 



Two com- As there are two oxides of iron, so there are also two dis- 



pounds of iron tinct combinations of this metal and chlorine. One may be 

 atic acid. directly formed by the combustion of iron wire in chlorine 



2d compound, gas ; it is that volatile compound described by sir Humphry 

 Davy in his last Bakerian Lecture, which condenses after 

 sublimation in the form of small brilliant iridescent plates.* 

 1st compound. The other, I find, may be procured by heating to redness, 

 in a glass tube with a very small orifice, the residue which is 

 obtained by evaporating to dryness the green muriute of iron ; 

 it is a fixed substance requiring a red heat for its fusion; it 

 is of a grayish but variegated colour, of a metallic splendour, 

 and of a lamellar texture. As it absorbs chlorine when 

 heated in this gas, and becomes entirely converted into the 

 volatile compound ; and as the volatile compound may like- 

 wise be obtained by heating in a glass tube, nearly closed, 

 the residue from the evaporation of the red muriate, it is evi- 

 dent, that the fixed compound contains less chlorine than the 

 volatile, and that the former, consequently, may be called 

 ferrane, and the latter ferraiien, 

 Itsjulution in Ferrane dissolves in water and forms the green muriate of 

 *'''^'^' iron; but the solution of the whole substance is not com- 



* Journal, to), XXIX, p 226, 



plete 



