466 



SCIENCE 



[N. S. Vol. XLIII. No. 1109 



A CHEAP ROCK POLISHING MACHINE 



A SMALL high-speed carborundum wheel, 

 clamped to one of our work tables, has long 

 been used for its obvious purposes. It may 

 interest those geologists and paleontologists 

 who have not stumbled on to the same fact to 

 know that this machine offers a most efficient 

 and rapid method of obtaining a polished sec- 

 tion of a rock or a fossil. My attention was 

 first called to this use of the machine during 

 a conference with Mr. Eobert Harvie on the 

 organic identification of some obscure mark- 

 ings in a calcareous sandstone. By splitting 

 the rock in an ordinary screw press and hold- 

 ing the desired portion of the exposed face 

 against the side of the wheel, for which pur- 

 pose there is a convenient rest, three flat sec- 

 tions were made and studied in as many min- 

 utes. The method is somewhat crude, but 

 efficient, and may have wide application. A 

 higher polish could be secured by using wheels 

 of differing degrees of fineness. 



Lancaster D. Burling 



Geological Survey of Canada 



the smithsonian physical tables 

 To THE Editor of Science: The Smithson- 

 ian Institution has just published a new edi- 

 tion of the Smithsonian Physical Tables, cor- 

 rected and slightly modified from the sixth 

 revised edition. Requests have come from cer- 

 tain educational institutions for separate cop- 

 ies of certain individual tables for the use of 

 students in laboratories. If there is likely to 

 be a considerable demand for such separates, 

 the institution will have them printed on stiff 

 paper and distributed at cost to those who de- 

 sire them. With a view to ascertaining the 

 probable demand for separate tables, it is re» 

 quested that readers of Science inform the 

 institution which tables they would desire in 

 separate form and the number of copies of 

 each they would require. All tables for which 

 the probable demand of this kind reaches 100 

 copies will be reprinted separately. The tables 

 may be consulted in nearly all of the larger 

 libraries. 



C. D. Walcott, 



Secretary 



SCIENTIFIC BOOKS 



Temperatur und Lehensvorgange. Von Aris- 

 tides Kanitz. Verlag von Gebriider Bom- 

 traeger, Berlin, s.s. 175 mit 11 textfiguren. 

 1915. 



" Temperatur und Lehensvorgange " is the 

 first of a series of biochemical mongraphs (Die 

 Biochemie in Einzeldarstellungen), written by 

 specialists, to be published by Gebriider Born- 

 traeger under the editorship of Aristides 

 Kanitz. The series will treat of biological 

 chemistry in its broadest sense and is com- 

 parable to the English monographs on Bio- 

 chemistry edited by Plimmer and Hopkins. 



It has been known for a long time that tem- 

 perature has a very great influence on life 

 processes, but only within recent years has a 

 quantitative study been made and the values 

 obtained compared with the effect of tempera- 

 ture on various physical and chemical proc- 

 esses. According to Kanitz the first quantita- 

 tive studies were made by Clausens in 1890 on 

 the carbon dioxide production of seedlings and 

 the results interpreted by van't Hoff in terms 

 of his rule — that the velocity of chemical re- 

 actions increases two- to three-fold for every 

 ten degrees rise in temperature. Since that 

 time many quantitative temperature investi- 

 gations have been carried out with special 

 reference to van't Hoff's rule or the EGT 

 (Eeaktionsgeschwindigkeit) rule as Kanitz 

 prefers to call it. These investigations are 

 systematically recorded in the book, which is 

 unusually complete. Often the original data 

 are given and always the value of Qj„, which 

 indicates the rate of increase of any physio- 

 logical process for a 10° C. rise of temperature. 

 References are made to 363 original papers 

 and the book contains both a subject and an 

 author's index, besides a table of contents, so 

 that any subject may be found with the 

 greatest ease. The effect of temperature on 

 various rhythmic processes, as heart beat, 

 breathing, contractile vacuoles and contraction 

 of medusae; on the rate of the nerve impulse, 

 muscle contraction, electromotive force of bio- 

 electric currents, geotropic and phototropic 

 reactions, protoplasmic streaming, permeabil- 

 ity, effect of poisons, the length of life, rate of 



