1872.] Notices of Books. 249 
details of spectroscopic analysis is in nearly every instance 
trustworthy; while in the few instances where there 1s room for 
questioning Dr. Schellen’s accuracy, the editor supplies, in a 
foot-note, the necessary emendation. The latter portion of 
Part II., in which the various orders of spectra are described, 
and the application of the analysis to the investigation of terres- 
trial substances is considered, becomes thus exceptionally 
valuable ; for to Schellen’s own familiarity with the subject, and 
his careful study of the labours of Bunsen, Kirchhoff, Thalén, 
and other continental spectroscopists, is superadded Dr. Hug- 
gins’s independent mastery of this departnient of the new science. 
And we cannot but notice here how little acquaintance with the 
history of spectroscopic analysis is displayed by those who sup- 
pose that Dr. Huggins’s application of the analysis to the heavenly 
bodies includes the whole of his labours as a spectroscopist. 
We would invite those who entertain this opinion to the study of 
BiGa 7. 
Changes in the form of a Prominence. 
Dr. Watts’s useful treatise, the ‘“‘ Index of Spectra,” noting that 
all the work by Huggins recorded and tabulated in that work 
preceded those astronomical labours which have been regarded 
as justly entitling him to be called the Herschel of the Spectro- 
scope. 
Before passing to the consideration of the last part of Schel- 
len’s work, we would invite attention to the extreme interest of 
those spectroscopic researches whose difficulty depends on the 
™minuteness of the quantity of matter placed under analysis. If 
our wonder is excited when we see a Huggins or Secchi ob- 
taining, from beyond the immeasurable distances which separate 
VO. dks (N:S.) 2K 
