188 On some new analytical Researchei 



' strongly ignited together, and the emission of ammonia 

 from them. I thought it possible, that in this case a sub- 

 stance mioht be formed siinilar to the residuum described 

 in pasre 487 (Philosophical Magazine, vol. xxxiii.) ; but by 

 coolino" the mixture out of the contact of nitrogen, 1 found 

 that no anniionia was formed ; and this substance evi- 

 dently owed its existence to tlie absorption of atmospherical 

 air by the charcoal *. 



The experiments that I have detailed on the acids, offer 

 some new views with respect to the nature of acidity. That 

 a compound of muriatic acid with oxide of tin or phospho- 

 rus should redden veoetable blues, might be ascril)ed to a 

 species of neutralization, by the oxide or inflammable body; 

 but the same reasoning will not apply to the dry compounds 

 which contain acid matter only, and which are precisely 

 similar as to this quality. Let a piece of dry and warm 

 litmus paper be moistened with the compound of muriatic 

 and phosphorous acid, it perfectly retains its colour. I>ct it 

 then be placed upon a piece of moistened litmus paper, it 

 instantly becomes of a bright red, heats and develops mu- 

 riatic acid gas. 



All the fluid acids th;it contain water are excellent con- 

 ductors of electricity, in the class called that of imperfect 

 conductors; but the compounds to which I have just al- 

 luded, are non-conductors in the same degree as oils, with 

 which they are perfectly miscible. When I first examined 

 muriatic acid, in its combinations free from moisture, I 

 had great hopes of decomposing them by electricity ; but 

 there was no action without contact of the wires, and the 

 spark seemed to separate no one of their constituents, but 

 only to render them gaseous. The circumstance likewise 

 applies to the boracic acid, which is a good conductor as 

 long as it contains water; but which, when freed from 

 water and made fluid by heat, is then a non-conductor. 



* Potash or pearlash is easily decomposed bv tlie combined attractions of 

 charcoal and iron; but it is not decomposable by charcoal, or, when per- 

 fectly dry, by iron alone. Two CDinbustible bodies seem to be required by 

 their combined affinities, for the ellect ; thus in the experiment with the jruu 

 barrel, iron ir.d hydrogen are concerned. I consider Homberg's pvro- 

 phorus as a triple compound of potassium, sulphur, nnd charcoal; and in 

 this ancient process, the potash is probably decomposed by two aiiinilies. 

 The substance is perfectly imitated by heating together ten parts of char- 

 coal, two of potassium, and one of sulphur. 



M'^hen 1 first showed the production of potassium to Dr. Wollaston in Oc- 

 tober 1807, he stated, that this new fact induced him to conceive that the 

 action of potash upon p'atina, was owing to the formation of potassium, and 

 proposed it, as a matter of research, whether the alkali might not bo de- 

 composed by the joint action of platina and charcoal, 



8 The 



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