THE vital importance of the library as a part of the equipment of a research laboratory is implicitly acknowledged in the Review of Scientific Instruments by the attention given to the current literature of physics in each number of the journal. Twice a year special book numbers are issued, and the spring book number (13, No. 4, April, 1942) contains twenty-four pages devoted to reviews of thirty-eight books on physics. In addition, a two-page “Condensed Library Guide for the Physicist” gives a summary of the standard sources of reference. Copies of the list for the use of students can be bought in quantity from the American Institute of Physics, 175 Fifth Avenue, New York. The list serves as a reminder of the extent to which physics lags behind chemistry in bibliography. The usual monthly survey, “Current Literature of Physics”, deals with the research journals. The latest reference to an English journal appears to be that to the issue of NATURE dated February 7.