EXPERIMENTS ON MURIATIC ACID CAS. 125 



indeed when it is considered, that in France much more 

 frequent opportunities are afforded of examining the stratifi- 

 cation iramedmtely above the chalk than in England, it will 

 not be regarded as improbable, that several of these beds or 

 patches may exist here, the discovery of which would render 

 the accordance of the two series of strata much more close. 



Even from the examinations, which have been already 

 made, the identity of the French and English chalk is esta- 

 blished. The British strata above the chalk are also found 

 to contain patches of plastic clay, of most of the varieties 

 mentioned in the French strata, as well as patches of coarse 

 limestone, with its accompanying sand and its peculiar 

 fossil shells, such as are found to exist in the corresponding 

 French strata. 



The other difference, the existence, in France, of beds 

 of sand and of sandstone above those of gravel, which are 

 the highest strata of this island, is very remarkable. May 

 it not be attributable to tHe abruption, from this island, of 

 the superior strata or beds of this formation, by that catas-> 

 trophe, instances of the astonishing force of which have been 

 already noticed ? 



VII. 



Experiments on Muriatic Acid Gas : by J. Murray, t.e&i 

 t^rer on Chemistry^ Edinburgh, 



To Mr, NICHOLSON. 

 SIR, Edinburgh^ Dec. 28, 1811. 



JL HE state of my health h^s not allowed me to send you Reason ef 

 an earlier account of the farther experiments on the nature ^^'*Ti 

 of muriatic and oximuriatic acids, which lannouncsd in my 

 last communication. I now beg leave to submit them to 

 the attention of your readers. 



I have already observed (Joui'nal, vol. XXVIII, p. 139,) Two modes of 

 that there are two modes of investigation, by which the Se"of oxi- 

 question at present under discussion with regard to the muriatic ^cid, 



nature 



