6 P. C. Ray— On Mercuroue Nitrite. [NY>. I, 



Evidence as to the salt being a nitrite pur i e and simple. 



As the Crum-Frankland does not enable us to discriminate between 

 the nitrate and the nitrite, use was made of the well known reaction 

 between urea and nitrous acid.* 



It was found that the solution of the ous and ic salt was only 

 slowly and imperfectly acted upon by dilute sulphuric acid, it was 

 therefore treated with pure caustic soda and warmed, In this way 

 the nitrite was converted into an alkaline salt. 



Substance = 0*7285 gram. ; Vol. of Sol. =100 o.c, 



After absorption of C0 2 by strong lye : 



4 c.c. sol. = 2*85 c.c. N /t = 32 c C. 



5 do. =3*55 do. j 



10 do. =7*10 do. 'p = 756m,m. 



Whence NO =11*7 per cent. 



As the urea also gives up the whole of its nitrogen according to the 

 equation given below, the experimental error is thus diminished by half. 



2 HNO a + CON 2 H 4 = C0 2 -t^Ng+SHgO. 



Dunstan and Dymond's method of estimating nitrites was niso 

 applied ; but in this case it is extremely difficult to prevent leakage of 

 traces of air. The result in general was rather high. 



The mean of the several estimations of nitric- oxide is 11*74. 



Discussion of the Results and Theoretical Considerations. 

 The results accord well with the formula : 

 HgN0 2 +l/2H 3 0.t 



Theory. Found. 



Hg = 200*00 .78*43' 78*55 



(NO = 30*00 11*77 11*74 



I O = 1600 6*27 



1/2H 2 = 900 3-53 



255*00 100*00 



On dilution with a sufficiently large quantity of water, the salt 

 moreover undergoes dissociation ; thus : 



Hg 2 (Is T 2 ) 2 =Hg + Hg(N0 2 ) 2 , 



* For details of this process see " A gasometric method of determining nitrous 

 acid, " by P. F. Frankland. Cliera. Soc. Jour. LI 1 1, 364. 



f While correcting the proofs I may as well mention here that the salt has 

 the formula Hg 2 N0 2 . Since the memoir was presented to the Society, I hare made 

 repeated analyses of it, the mercury being estimated as sulphide, as phosphorous 

 acid gives very low results in presence of nitrous acid. The percentage of '• free " 

 mercury has been found to be 31*41, that in the ic salt, 31*41 and that in the 

 ous salt, 17'8 : total 80'62. Theory for Hg^NOg requires 81*3. 



