Spectrum Analysis

THAT there is a real need for a fairly comprehensive text-book of spectrum analysis of moderate size will be acknowledged by all who have occasion to teach the principles of the subject, or to employ its methods for analytical purposes. To meet this need appears to be the object of the book before us, though it does not claim to be exhaustive. The treatment of the subject is historical throughout, and there is a great number of useful references to important memoirs, while particulars of the spectra of elements and compounds occupy nearly one-third of the volume. As a general text-book of the subject, apart from its astronomical applications, the book has much to recommend it; but it leaves a great deal to be desired as a guide to the practical details of spectroscopic work, which, as the translator remarks, “furnishes so many opportunities for an excellent training in accuracy of observation and manipulative skill.” The lack of the practical touch is frequently indicated. In the table of magnesium lines (p. 143), for example, the lines of the arc and spark spectrum are grouped together, and the omission of the most striking line of the latter at λ 4481, possibly for the reason that it is all but invisible in the arc, might cause much loss of time to a student who happened to observe this line and attempt to ascertain its origin. Again, there are no instructions for photographing spectra, although in the majority of cases this is by far the best method to adopt in practice. Least satisfactory of all, the whole subject of comparing observed with tabulated spectra is far too cursorily dealt with to be of real value to the practical student.Spectrum Analysis.By John Landauer Authorised English edition by J. B. Tingle, Ph.D., F.C.S. Pp. 239 + x. (New York: Wiley and Sons. London: Chapman and Hall, 1898.)