476
XEIV BOOKS.
high value set on "teachableness" is rliic, sonirtirnes. :is much to consideration for self as for students. But the reviewer does not wish to be misuiitlr-rstood, the good points of the book overbalance those which do not happen to coincide with his own, perhaps peculiar, notions, and the proof of his appreciation is t h a t lie intends to recommend i t a s one of the two or three bcst elementary texts known to him. S. LA\VREXCI: Blc,er,ow. Die Kathodenstrahlen. By G. C. SCHNIDT. Prof. PPhys. 1:niv. KDnigsberg. Second editon. Braunschweig: F. Vieweg und S o h . I ( ~ O ; , 1 2 7 pp, Price, Mark, 3.60, bound.
This monograph, which forms No. 2 of the collection, Die 1i;issenschaft, gives a clear and concise account of our knowledgc of the electric discharge in evacuated vessels. The book is iiitcndecl for the 11011specialist; the use of niathematics is almost \iTliolly avoided; yet, by means of well chosen illustrations and ingenious :inalogics, tlic reader is easily led to an accurate understanding of this niost fascinating siibject. 'I'he topics treated include the nature of light and tlic luminous ether; tlie cathode rays, their production and behavior, togetlicr with :in escellent critical discussion of the various hypotheses regarding their nature ; the nature of the electron or corpuscle, its vclocity, charge a1:d mass; the Zeeman effect; the canal rays, etc. 'I'his little book is a I\.elcoi11c addition to the semi-popular literature oi the corpuscle, the primitive unit of which all matter seems to be built up. IIIIIZI:I:RT S . NcCos: The Microscopy of Technical Products. 1:roin the Germnil of Dr. T.I:. Hanausek. Translated b y Andrew L. Winton, P h D., n.itii tlic collaboration of Kate G.IJarixr, Ph.D. Kew Uork: John \%ley & Sons. 190;. Svo, s i i i 4 : i pages, 276 iliustrations. Price, $5.00.
This book which has enjoyed a well established rcpiitation in the original is now presented to English readers in the i w r k of Dr. \Tinton. While not dealing with chemical methods of identification, esccpt incidentally, i t nevertheless must possess 110 little interest for those chcmists who are engaged in various lines of cspclrt tcstiiig work iii which recourse to the microscope is often absolutclv neccss:iry. The portion of the book which will be found the niost L:scful t o nnalytical cheinists are the chapters on the starches, steins aiitl roots ant1 fruits and seeds. These are clearly written ant1 illiistratctl. The rapid extension of the natioi:al arid state food and drug la\vs makes the kind of knowledge contained in this book cipeciully \-aluable a t the present time. The translator is a t the hear1 of tllc Govcrnmeiit Food and Drug Laboratory in Chicago arid has had L: long experiericc in the line of work discusscd in the book. Froin this pr:ictical experience he has been able to make more thaii a Lr:,rislatimi of it, a'i tlic i i ~ ~ . ~ i i e r o u s notes attest. 'l'hc illustrations, esseiiti:d i i i :i work of this character,
