ON POTASSIUM, 8«DIUM9 AND OXIMURIATIC ACID. 22^ 



VII. 



Remarks on Potassium y Sodium, Sfc, ; in Reply to the Com* 

 municalions o/Jvstuh. By John Dalton* 



To Mr. NICHOLSON^ 

 SIR, 



-ilN perusing the former of the two communicationg, pur- 

 porting to be a reply to the remarks on potassium and so- 

 dium in ray New System of Chemical Philosophy, (Journal, 

 vol. ^iS, p. 67) I felt interested in various acute observa- 

 tions of your correspondent; but at p. 72, where he inves- Quantity of 

 tii^ates the quantity of oxiwn in a eivcn volume of oximu- oxigen in oxi- 

 • *• • I T * . 1 ? • u u , J muriatic acid, 



natic acid gas, I am quite at a loss to conceive now he had 



obtaIn»ed so small a portion as 30*24 percent, when I had 

 found 50, (New System, p. 56O) calculating from the best 

 data I could procure, and which I was confident from my 

 own experience could Tiot be materially incorrect. Being 

 at that time particularly engaged, I could not attend to the 

 subject farther than to write a short note (Journal, p. I57J 

 requesting an explanation. This was given in the ensuing 

 number, (p. 219.) When I stated, that his data were de- 

 fectivey I did not mean erroneous ; no mathematician would 

 have understood me in that sense; I meant, that he had not 

 given sufficient data, and consequently that he had made 

 the problem an unlimited one. If I should propose the fol- 

 lowing question to your correspondent, namely, IJoxo long 

 7vouJd a body he in moving with a uniform velocity from the 

 Earth to the Moon, or through a space of 240,000 miles — 

 would he not find it necessary, that the velocity should be 

 given? Yet he has found means to answer a similar ques* 

 tion without the requisite data. The accuracy of the 

 answer then may well be suspected. It may be of service 

 toyourcorrespondent, and perhaps to others of your readers, 

 if I make out this charge more particularly. According to 

 Chenevix, 

 77*5 mur. acid + 22*5 oxigen zr lOOoximur. acid, by wt, 



1*73 



then, by measure 77*5 mur. acid X 22*5 oxi. =115: 



1 '\i.5 

 measures; 



Vol. XXIX.-.JUNE, 1811. ^ Thit 



