PROF. BRUSH has endeavoured to make the study of mineralogy lighter than usual, and has in many respects succeeded, but unfortunately for the modern student he has retained the old chemical formulæ. Surely it would have been better to swim with the times and adopt the new atomic weights, taking care to abolish all doubtful tests, and adding the latest and most accurate methods of analysis. Many of the latest and most delicate methods of mineral analysis are entirely omitted, such as Bunsen's methods for the detection of arsenic, antimony, selenium, molybdanum, uranium, &c. The work in question is divided into two distinct parts; the first containing descriptions of the different apparatus and reagents used, and a “Systematic Course of Blowpipe Analysis;” the second, styled “Determinative Mineralogy,” makes use of the knowledge acquired in the first part to determine the mineral species under examination. The “Systematic Course of Blowpipe Analysis ” is adapted from the later editions of Plattner's work on Blowpipe Analysis, edited by his successor, Prof. Richter; the “Determinative Mineralogy” is a translation of Von Kobell's “Tafeln zur Bestimmung der Mineralien,” tenth edition. Generally speaking, students do not take kindly to “Tables,” but Prof. Brush has made them more inviting by arranging the minerals having the same base into groups, and studying them in order. This is an excellent arrangement, and the distinguished author deserves the gratitude of students for thus lightening their labours. Too many mineralogical works of the present day exhibit a harum-scarum kind of classification, which simply bewilders the inquiring student and leaves him in greater confusion than before. The first part of the work opens with descriptions of various kinds of blowpipes, and the manner of using them, also the fuel used to obtain the requisite flame. Here, under the headings “Reducing” and “Oxidising” flames, are described very clearly the characters of the two flames, with very good engravings showing the zones. The methods for preparing the various reagents required are trivial and should Lhave been omitted; for instance, we are told to prepare pure carbonate of soda by taking “four or five ounces of commercial bicarbonate of soda free from mechanical impurities,” &c. We should be glad to know where Prof. Brush obtains his commercial bicarbonate of soda so free from impurity, as the manufacturer deserves encouragement. Chapter II. commences the “Systematic Course of Qualitative Blowpipe Analysis,” describing the reactions of the elements and their combinations in the “closed tube and open tube,” and on “Charcoal as a support.” Under the latter heading a very neat and novel method is given for overcoming the great difficulty experienced sometimes in keeping the assay in its place on the charcoal. Let those who wish to work in comfort for the future buy the book, and find the method therein. Manual of Determinative Mineralogy, with an Introduction on Blowpipe Analysis. By George J. Brush, Professor of Mineralogy in the Sheffield Scientific School. (New York: John Wiley and Son, 1875.)