"14 Sketch o/' the latest Improvements [Jax. 



Christian Frederick Bucholz made a set of esperiments, ia iyi2, 

 to determine the quantity of oxygen which can be obtained from 

 hyper-oxymuriato of potash. His experiments were not attended 

 with much success ; but he ascertained that a red heat is necessary 

 to drive off this gas. 1 have myself repeated this experiment more 

 than once, and obtained a result which approached very near to 

 that previously established by the experiments of Chenevix. 



3 Fluorine. — Sir H. Davy has published several papers upon tliis 

 hypothetical basis of fluoric acid ; but all attempts to obtain it in a 

 separate state have hitherto failed. Indeed, supposing it to exist, 

 its action upon all other bodies seems necessarily to be so violent 

 that there can be little hopes entertained of ever procuring it except 

 in a state of combination. 



4. Azote. — The two laws of Berzelius relative to chemical pro- 

 portions do not hold when applied to the combination of azote with 

 oxygen. The reason of this he conceives to be, that azote is not an 

 element, but a compound of oxygen and an unknc^n base, to 

 which he lias given the name of iiitrkum. He has calculated from 

 his theory the quantity of oxygen which azote must contain; and 

 he shows that when this correction is made, tlie nitrates, as well as 

 other bodies, couie under the dominion of his two laws. 



Mr. Miers, of London, had been of opinion for several years 

 that azote is a compound of oxygen and hydrogen, and that the 

 experiments of Girtanner were not so inaccurate as has been sup- 

 posed. In a paper published in the Annals of Pliilusophi/, vol. iii. 

 p. 364, he shows that the supposition, that it is a conijiouiid of one 

 atom oxygen and six atoms hydrogen, will tally exactly with the 

 atomic theory, and give the weight of the different atoiris into which 

 azote entered tiie very same as they are at present, sujjposing azote to 

 be a simple substance. This ingenious paper was sufficient to show us 

 that the opinion of Mr. Miers was neither impossible nor impi'obable. 

 It was not, however, suflicient to determine the opinions of chemists' 

 in favour of an hypothesis of so much imjjortance, that the conse- 

 quence of admitting it would be an almost entire change in the 

 notions at present entertained respecting chemical coiiibination. 



Mr. Miers, sensible of the necessity of direct experimental proof 

 in order to give currency to an opinion of such magnitude, has had 

 recourse to direct experiment, and has published a very curious and 

 valuable paper on the subject in the Annuls of Philosophy, vol. iv. 

 p. 1 80 and 260. His object in these experiments was to deprive 

 water of a portion, but not the whole, of its oxygen, and thus to 

 convert it into azote. The experiments of Girtanner were directed 

 to precisely the same view, it occurred to Mr. Miers that sul- 

 phureted hydrogen gas would probably answer tlie purpose. Accord- 

 ingly he passed a mixture of vapour of water and sulphureted 

 hydrogen gas through a copper tube. In one experiment the whole 

 gas that came over possessed the properties of common air, and was 

 a mixture ot'80 azote and 20 oxygen. In another a gas was formed, 

 which Mr. Miers considered as sulphureted azotic gas. In a third 



