Dr.Vve on Chlorifk of Lime. 25 



of manganese to that of carbonic acid, 2.75. We shall pre- 

 sently see, however, by another experiment, on Richter's prin- 

 ciple of reciprocal saline saturation, lately revived by Doctor 

 Thomson, that 4.5 is the true number, in exact accordance 

 with this chemist's late atomical determination *, Hence, 

 instead of 35.4 grains of carbonic acid, 35.2 should have been 

 obtained; an error within the limit of careful experimenting. 

 The proto-carbonate, formed as above, consists, therefore, 

 of carbonic acid . . . 2.75 35.2 



Protoxide of manganese 4.50 57.6 



Water, 1 atom to 2 atoms 



carbonate ... 7.2 



100.0 

 Sulphate of manganese dried at a heat of 212° F., consists of 

 one atom of water and one atom of sulphate of manganese. 

 Of the same salt, exposed to very gentle ignition, I took 9 § 

 grains (= 5 acid + 4.5 oxide), and dissolving them in water, 

 added to this solution, another containing 13.25 of muriate of 

 barytes (=45 chlorine + 8.75 barium). After subsidence of 

 the sulphate of barytes, the supernatant muriate of manganese, 

 was found to be entirely free from every trace of both sulphuric 

 acid and barytes. Therefore, 5 sulphuric acid are equivalent 

 to 4.5 protoxide of manganese ; and, of course, 2.75 carbonic 

 acid to the same weight of oxide. 



Thirty grains of proto-carbonate, containing, as above, 17.31 

 of protoxide, formed by ignition in a platina capsule 21 of 

 black peroxide. But 17.31 : 4.5 :: 21 : 5.46, a number which 

 clearly indicates 5.5 to be the atomic weight of this substance, 

 which is therefore a deutoxide. The prime equivalent of the 

 metal is consequently 3.5 ; the intermediate oxide of which 

 Dr. Forschammer treats, appears to me to b3 the result of a 

 combination of the above two, or it holds the same relation to 

 them that minium does to lithage, and to the puce-coloured 

 oxide of lead. 



We may now conclude that 5.5 parts of pure deutoxide of 

 manganeee, when acted on by muriatic acid, should afford 4.5 

 * 'jwuih nf Phil., Neu- Series I. p. 241. 



