Ozone to Hyponitric Acid. 435 



which is similar to that of common aquafortis, and slightly 

 analogous to the smell of chlorine. It is likely that the odour 

 mentioned belongs to the vapour of our supposed peroxide 

 of nitrogen and hydrogen, and that it is that compound which, 

 if inhaled, causes the sensation before mentioned. With re- 

 gard to the subject under discussion, it seems to me that the 

 way in which the mixture, formed from hyponitric acid and 

 water, acts upon a solution of the yellow prussiate of potash, 

 offers peculiar interest. 



My experiments having demonstrated that the salt just 

 mentioned (be it solid or dissolved in water) is readily trans- 

 formed into the red cyanuret by ozone, and considering the 

 acid mixture before alluded to as an aqueous solution of nitric 

 acid and peroxide of nitrogen and hydrogen, what must happen 

 if that mixture be put together with a solution of the yellow 

 prussiate of potash ? Supposing 1 equiv. of the said peroxide 

 and 1 equiv. of nitric acid in the acid mixture to act upon 2 

 equiv. of the yellow cyanuret, we must obtain from such a re- 

 action 1 equiv. of nitrate of potash, 1 equiv. of the red sesqui- 

 ferrocyanuret of potassium, 1 equiv. of deutoxide of nitrogen, 

 and 2 equiv. of water, for 



(N0 4 + H0 2 ) + (N0 2 +H0 2 ) + 2(2PCy + FeCy) = PON0 6 

 + (3PCy + Fe 2 Cy 3 ) + N0 2 + 2HO. 



If a glass tube, open at one end, be half-filled with our acid 

 mixture and half with a dilute solution of the yellow prussiate, 

 on mixing the liquids together a lively disengagement of gas 

 takes place ; and if the open end of the tube be put into a ves- 

 sel holding water, a colourless gas will fill the upper part of 

 the tube. On adding oxygen or atmospheric air to the gas 

 disengaged under the circumstances mentioned, the latter will 

 turn brownish red and exhibit all the properties of deutoxide 

 of nitrogen. As soon as the acid mixture comes in contact 

 with the nearly colourless solution of the common prussiate of 

 potash, the latter turns deeply yellow, and it is very easy to 

 ascertain that the coloured fluid contains nitrate of potash, 

 sesqui-ferrocyanuret of potassium, and no trace of the yellow 

 prussiate, provided a sufficient quantity of the acid mixture 

 had been employed. The reactions indicated are therefore 

 such as they ought to be, if, according to our supposition, the 

 acid mixture contains nitric acid and peroxide of nitrogen and 

 hydrogen. I need hardly say that the disengagement of deut- 

 oxide of nitrogen and the transformation of the yellow cya- 

 nuret into the red one, which take place under the circum- 

 stances mentioned, cannot originate in the nitric acid contained 

 in the acid mixture, for it is well known that dilute pure nitric 



