On the Idenllty of Silcx and Oxygen. J 63 



The same thing: may also be proved by looking at an 

 object th()ii(2,h perioralions of dilVerent dimensions 5 tor it 

 will appear snialier through a perforation of yJi-jj- of an inch, 

 than through one that is four times as large; and an object 

 viewed through a perforation as large as the pupil, appears of 

 the same magnit-ideas to the naked eye. 



Whence it is manifest, that all tenestiial objects appear 

 larger to the naked eye in the mornings and evenings, 

 when the pupil is large, than at noon when the pupil is leis ; 

 and for the same reason they appear larger in winter than in 

 summer. 



I ani; sir, your humble servant, 



E. Walker. 



Lynn, 

 March 18, 1808. -^ 



XXXII, On tlw Identity of Sllex and Oxygen. By Mr, 

 Hume, of Long- Acre, London, ' 



7b Mr, Tilloch, 



SIR, 



JL o inculcate any science with success, there is nothing so 

 essential as a simple and perspicuous display of its lirst prin- 

 ciples ; and if there be any department in j)hil()Sophy to 

 which this observation is uiore peculiarly applicable, it is 

 certainly the study of chemistry, than which there is, pro- 

 bably, none more useful to man. 



The present period is, of all others, the most opportune 

 for an improvement in chemical theory, as, from the very 

 brilliant discoveries of Professor Davy, it is ob-.''ous that a 

 most material revolution is now dawning upon tlic modern 

 system of chemistry, anfl, possibly, an entirely new struc- 

 ture must eventually prevail. 1 now allude to the word 

 oxygen particularly, which, in its present limited sense, 

 stands as a solecism in language, and a mere absurdity in 

 the nomenclature of the day, since it has been lately proved 

 to be at once the principle of acidity and likewise that of 

 alkalescence, 



Jn all modern authors, the classification of simple and 

 L 3 eknien- 



