262 On the red color of flame as affected by certain minerals. 



As might be expected, the sulphates of lime, when similarly treat- 

 ed, are deficient in the character of reddening flame, unless, as is 

 not uncommon, some carbonate of lime is present. 



With regard to the sulphate of strontian found at this place, I 

 am inclined in this case also, to attribute the rose red color which, 

 when treated with muriatic acid, it communicates to flame, to the 

 presence of some carbonate of lime ; for, after digesting its powder 

 in muriatic acid and washing it, a repetition of the process before 

 found to be successful, fails to produce the red color. 



Having just perused your note upon this subject, in the last number 

 of the Journal, I feel more inclined to think the above opinion correct. 

 Had carbonate of strontia been present, the washing would not have 

 prevented the exhibition of the colored flame.* 



I converted a portion of the sulphate of strontian into a sulphuret, 

 by mixing it, in a state of powder, with one eighth of its weight of 

 charcoal and submitting the whole in a crucible to a red heat 

 for four or five hours, but I found that it still required the presence 

 of muriatic acid to develop the rose colored flame, and I could 

 observe no other effect produced, in that respect, than an increas- 

 ed development of the coloring matter both in point of quantity and 

 strength. From these observations it appears to me 



1st. That to give a red color to flame is not peculiar to strontian. 



2nd. That the natural sulphate found here, does not appear to do 

 so, unless muriatic acid and lime be present. 



3rd. That the earths of barytes would also appear to exhibit that 

 character if moistened with muriate of lime. 



4th. That however distinguishing this character may be between 

 the two earths in the state of purity, it is not one, upon which any 

 dependence can be placed in order to distinguish them in their natural 

 state unless any portion of lime which may be accidently present is 

 removed previously to decomposition. It would be an interesting in- 

 quiry how far the coloring principle in the muriate of lime and pure 

 strontian may be the same, an investigation which might repay the 

 individual who engaged in it, by some interesting discovery. 



In the absence of that satisfactory species of evidence which 

 chemical analysis affords and in consequence of what has been 



* It appears reasonable in consequence of the interesting facts stated by Lt. Bad- 

 deley, to attribute the red color in this case, to the presence of carbonate of lime ; 

 but had carbonate of strontia been present, it would, by the same treatment, have 

 been turned into muriate which would have also reddened flame, and being a very 

 soluble salt, it would have been removed by the washing. — Editor. 



