Notices respecting New Boohs. 213 



" All substances begin to be red-hot at the same temperature in 

 the same enclosure. 



" The Spectrum of solids and liquids contains no fixed lines."* 

 Now it may be said with very little qualification that what is here 

 attributed to M. Kirchhoff is to be found distinctly stated in the first 

 memoir in the volume before us, which was published by Dr. Draper 

 in 1847. By experimenting with a strip of platinum heated by the 

 transmission of a current whose force could be regulated, he ascer- 

 tained that the temperature at which red rays are first radiated is 

 977° lahr. He also ascertained that platinum, brass, antimony, 

 gas-carbon, and lead became incandescent at the same time with 

 the iron barrel in which they were gradually heated, and that the 

 apparent exceptions presented by chalk, marble, and fluor-spar 

 were due to phosphorescence. By raising the temperature of the 

 platinum wire and analyzing with a prism the light emitted, he 

 proved that the length of its spectrum gradually increased with the 

 temperature until at 2130° Fahr. the full spectrum of daylight 

 was attained; and it is clear that he regarded the result thus ob- 

 tained as being generally true. That the spectrum of the incan- 

 descent platinum contained no dark lines did indeed come out only 

 incidentally in the course of the investigation : still it was not by 

 any means a point seen but not observed ; for, in consequence of 

 observing it he resorted to a comparison of the spectra of incan- 

 descent platinum at different temperatures with the spectrum of 

 daylight in order to determine their extent, instead of fixing their 

 extent by the dark lines of the spectra themselves, which he had as- 

 certained to be non-existent. On the whole the above statement 

 breaks down at nearly every point. What is therein referred to 

 M. Kirchhoff was certainly ascertained before by Dr. Draper. 

 "Whether Dr. Draper was the first person to observe all these points 

 is a very different question, and one we would by no means pre- 

 judge ; indeed, without going beyond the limits of the first memoir, 

 it is pretty plain that the temperature of incandescence was known 

 with considerable accuracy before Dr. Draper's experiment with 

 the platinum wire ; and it certainly was believed (if not proved) 

 that the temperature was the same for all bodies. 



Geological Survey of Canada. Report of Progress for 1876-77. 



A. E. C. Selw*w, F.R.S., F.G.S., Director. 8vo. Pp. 531. 



Dawson Brothers : Montreal, 1878. 



Besides the Introductory Report by the Director, this volume 

 contains the following important Eeports : — 1. On Geological Ex- 

 ploration in British Columbia, chiefly on the Blackwater, Salmon, 

 and Nechaco Rivers and Francois Lake ; by G. M. Dawson ; with 

 coloured map and seven very suggestive plates of local scenery. 



*The above quotation is, we presume, to be found on pp. 463, 464, vol. iii. ed. 

 1866. If so, it is not exactly a quotation, but is made up of parts of a much 

 longer statement. We may also observe that Memoir I. of the present volume 

 is not in all respects an exact verbal reprint of the Memoir published in our 

 Journal for May 1847. This does not, however, affect the point at issue. 



Phil. Mag. S. 5. Vol. 7. No. 42. March 1879. R, 



