Mr. R. Phillips's Lettei- to Dr. D. Boswell Reid. 425 



converted into peroxide; and consequently your assertion, 

 that protoxide only is obtained, and your diagram, by which 

 the assertion is illustrated, are both blunders. 



There now remains only one fact more for me to attend to; 

 and as you have not alluded to it in the Continuation,^ I should 

 have imagined that you had as tacitly admitted my correction 

 of this as of the fifty other mistakes already alluded to, if 

 you had not repeated it in the second edition of your Ele- 

 me7its, at p. 61. 



You tell us that you can see white vapours of nitrate of am- 

 monia blended with the nitrous acid vapours that are formed 

 when nitric acid is decomposed by a metal having great affinity 

 for oxygen. In my Letter I showed that no nitrate of am- 

 monia whatever was volatilized; and I challenge you to make 

 any experiment, to prove that nitrate of ammonia goes off in 

 white fumes; or to repeat the following, which shows that it 

 does not. I added at intervals nitric acid, ofsp.gr. 1*237, to 

 1200 grains of tin in a retort, till gas ceased to be evolved; 

 the very dilute nitric acid thus obtained was reduced to a 

 small quantity by evaporation, and lime was ihen added to it; 

 but not the slightest smell of ammonia was perceptible, nor 

 was any change produced in the colour of moistened turmeric 

 paper held over the mixture. Now this dilute acid must have 

 condensed the vapours of nitrate of ammonia had any been 

 produced. The test of turmeric paper used in this way is so 

 exceedingly sensible, that I found it detected the ammonia 

 formed by the action of nitric acid upon ten grains of tin. 

 The white vapours then which you have seen, but which you 

 have never examined, are not nitrate of ammonia. 



I shall now briefly state some assertions of yours, which I 

 call upon you to prove by experiment: — 



First : That antimony has less action with nitric acid of the 

 density of 1*48 than when it is either a little stronger or a little 

 weaker. 



Secondly: That nitrous acid is produced by the direct ac- 

 tion of mercury and some other metals upon nitric acid. 



Thirdly: That nitrate of ammonia sublimes at a lower tem- 

 perature than that required for its decomposition. 



Fourthly : That when 200 parts of mercury are heated with 

 300 of sulphuric acid, though not to dryness, no bi-persulphate 

 of mercury is formed. 



Fifthly : That when a metal having great affinity for oxygen 

 is acted upon by nitric acid, white vapours of nitrate of am- 

 monia are produced. 



In concluding, I beg leave to assure you that I shall have 

 great pleasure in publishing your reply to this letter ; and 



N.S. Vol. 11. N0.G6. JunelSS'l. 3 I perfectly 



