•ON TriK NATURE OF OXIMURIATIC CAS. 41 



a simple expression of facts, and the latter a series of sup- 

 , positions. 



I shall studiously avoid discussion in the remaining part 

 of this paper: it is my intention to confine myself to facts, 

 which speak for themselves, and are the only legitimate 

 l5upport8 of a theory. 



Mr. Murray asserts, that Mr. Davy is obliged to sup- Water pro- 

 .posCf that water is produced in the common mode of mak- oxide of man- 

 , liijy oximuriatic gas from muriatic acid, by means of the ganese is heat- 

 black oxide of manganese. Mr. Davy has ascertained the acid gaT.""*'^*^ 

 fact, that oximuriatic gas and water are produced, when ^ 



black oxide of manganese is heated in muriatic acid gas. 



Mr. Murray imagines a great intricacy in some parts of Mr. Dayy's 

 Mr. Davy's theory, which does not really belong to it; for gf^^'i^^J'* 

 theory, being an expression of facts, must be as simple as Mr. Munay 

 /the facts themselves. Mr. Murray, for instance, conceives, supposes. 

 /|bat, in the solution of muriate of potash in water, water 

 is decomposed ; and that it is recomposed at the moment 

 of its expulsion by heat. These are conjectures. In Mr. 

 pavy's theory, fused muriate of potash, I conceive, is a 

 compound of oximuriatic acid and potassium ; and the so- 

 lution of muriate of potash is a compound of oximuriatic \ 

 acid, potassium, oxigen, and hidrogen. The mutual de« 

 composition of nitrate of mercury and common salt is ano^ 

 ther supposed complicated instance pointed out by Mr. 

 Murray. It is this gentleman who imagines the changes 

 complicated. The facts are merely these : sodium surren- 

 ders its oximuriatic acid to the mercury, and receives in 

 return its oxigen and nitric acid, and thus calomel and ni- 

 trate of soda are very simply formed. 



Mr. Murray seems to consider every thing anomalous. Tilings not a«- 

 that is not accounted for; thus the want of action between always anoma- 

 charcoal and oximuriatic gas is in his opinion an anomaly lous. 

 in Mr. Davy's theory. Can Mr. Murray account for the 

 want of action between charcoal and nitrogen, and between 

 the metals and nitrogen ? and, if he cannot, does he conse-r 

 quently consider these facts anomalous .-* 



Mr. Murray doubts what I have alleged to be fact ; viz. Mercury de- 



that the composition of muriatic acid cas is uniformly the c°"?Pose'5 mu- 

 -, , /. , -M^ riatic acid ga$ 



game. 1 do not pretend to accoimt for the results of Dr. and forms ca. 



Henry's ^^*^- 



