268 On Aphlogistic Phenomena 
French inches; temperature supposed 10° of De Luc’s thermo- 
meter, or 17:14] English measure at 60 F.; water boiled at 
68-993°, which, as 80° was the boiling point for 27 French inches, 
is equal to 185-51° Fahrenheit. 
Now 17°141—:09=17°051=I1. Log. =1:23175 
+6 =0:20529 
+ 2°22679 
2:43208= 270-45 — 
§5 =185'45°, which corresponds. nearly with observation. A 
few more comparisons with experiments on mountains may be 
made ; Inches. Evp. Calc. 
On Buet, by De Luc 20964 194:°87° 194:72° 
Grenairon, De Luc 21:765 19660 196:48 
Mt. Cenis, Saussure 23-776 200-71 200°67 
Near Geneva, Shuckburgh 26-000 204-91 204-98 
As little dependance can be placed on any theorem for calcu- 
lating the force of steam much beyond the range of experiment, 
it is only an object of curiosity to examine what pressure would 
confine red hot water: suppose the heat 1000° F. and calcu- 
lating as before, gives 71,000 inches of mercury, or above 2300 
atmospheres, approaching to six miles of granite, which may 
perhaps be two or three miles too much. Steam of 2300 atmo- 
spheres would be more dense than water. 
Iam, &c. 
Soho, Staffordshire, March 1819. Wo. CREIGHTON. 
XLIV. On Aphlogistic Pheenomena and the Magnetism of 
Violet Light. By Mr. J. Murray. 
To Mr. Tilloch. 
Paris, March 24, 1819. 
Sir, — I. my Elements of Chemical Science, second edition 
(published by Messrs. Underwood of Fleet-street), I have, in com- 
mon with others, considered the aphlogistic phenomena dis- 
covered by Sir Humphry Davy, peculiar to the metals platinum 
and palladium; and assigned their relations to caloric as the 
cause, though I had early observed and pointed out the feeble 
phosphorescent flame which accompanied other metals, char- 
coal, glass, &c. when heated, and plunged into inflammable me- 
dia in contact with air. The opinion there given, I beg now to 
revoke. 
When at Naples, Professor Sementini informed me that silver 
and copper manifested the phenomena in questioa, and he was 
so good as to repeat these experiments, among others, before 
me, The light exhibited by the copper is less brilliant than a 
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