90 r.EGL TOOXS. 



scrvatwti xsottli notkc, and arc able to give me an aclcqnafji 

 CNplanalion, I shaTi be much obliged by your insertion of this 

 c\ies\vm as to note in some future number. 'Can it be owing to any chemi- 

 cal action rxcrted on the line edge of the metal bv the oxigen- 

 ous part of the t^fmosphere, whereby its qualify is so changed 

 as to cause it to yield more to the strap than it did before ? 

 I am, Sir, your constant reader, 



E. D. 



Tlipediior re- P. S. I waS pleased to see your annotations on the notice 

 ^roml^e're-'^* ^^ ^'^^' ^^^'■^ celebrated Lavoisier's posthumous collection of mc- 

 spoctin;!: f ;;- moirs ; and tio])e you hare not relinquished your intention of 



to thetlioorvof ^'''^''"-"^^'•"■'^ ^'^^•'"''^ ^''^'"^^'^^ '^"'- own plnlosophers agauist the 

 oxifhatifjii, unqualified claims of that author. 1 subj'oin the following re- 



page 84 marks whjch I lately met with on oxidation. By an expeii- 



Lavoisier was i^^ont of Mr. Ilomberg's, four ounces of regulus of antimeuy 

 nottbefiret being calcined by a burning-glass for an hour together, wert" 

 tlK- iiK-rease of ^^und fo have imbibed and fixed seven drams of the substance 



vv^-i^ht in o\i- of ]i(T],t. ' llcrc t!ie increase of weight by calcination is dec;- 



datioit of uie- . " ,,,.,.. ... , 



tais, sively remarked • Ihougli it is attibutcd to a wrong cause. 



HomlMT- ob- Put Dr. Hales says, " if fire was a distinct kind of body m- 

 scrvcd it in an- , T>rTTi it ■• 



tiinonyoxirlcd " Hcrent Hi sulpliur, as M, ilombcrg" and l-.cmerv nnagme,' 

 by solar heat, a (j^pn such bodies when ignited would rarefy and dilate all 

 Hales found l,y ^^ , . ,• , ■ t ■, ■ ,- , , 



experimeiittiiat ^'^^ Circumambient air, whereas it is tound by many of Ih" 



the £;aiii is from " preceding experiments that acid sulphureous fuel attracts 

 absorbed air. ' f ^ . , , , r . ■ 



" and condenses a considerable part ot the circumambient elas- 



" tic air."t And again he says, speaking of the weight which 



lead acquires by calcination, " that there is good store of air 



He separated " added to the minium, I found by distilling lirst 10-2i2 grains 



the air again " of lead, from whence I obtained only seven cubic inches of 



from the minium. ,, . i . r ..^/-.^ • i • i \ ■ - \ c- i 



" air; but from 1922 gauis, which was a cubic mch of red 

 " lead, there arose in the like space of time thirt}'^four cubic 

 " inches of air. It was therefore doubtless ihis quantity of air 

 ** in minium which burst the hermctrically sealed glasses of tho 

 " excellent Mr, B' vie, when he heated the m.inium contained 

 " in them by a burning-glass : but the pious and learned Dr. 

 " Nieuwentyt attributes this efiect wholly to the expansion of 



* Bp. Berkley's Slrius, par, 1G9. 

 t Ccg. Statice, 4th edit, p. 285,— Ibid. 209. 



-the 



