Chemistry and Physics. 457 



made experiments which indicate that the thin cracks extending 

 from -05 to '1™™ below the scratch made by the glass-cutting 

 diamond may be healed to a considerable extent in from one to 

 three days by gentle pressure. The experiments were conducted 

 by comparing the loads required to fracture freshly scratched 

 pieces of glass and those which had been slightly bent for several 

 days in such a way as to press together the ruptured surfaces. 

 — JBerichte, xxxiv, 3635. h. l. w^ 



6. General Principles of Physical Scioice ; by Aethur A. 

 Notes. 8vo, pp. 172. Xew York, 1902 (Henry Holt & Co.).— 

 The purpose of this volume is to present the principles and laws 

 of physics and chemistry which lie at the basis of the modern 

 science of theoretical chemistry. The treatment is non-mathemati- 

 cal to a great extent. The two main chapters of the book treat respec- 

 tively of the general principles relating to matter and to energy. 



The book forms the first part of a work on the general princi- 

 ples of chemistry, which has had to be discontinued. It is to be 

 hoped that Professor Noyes will continue the work in the future. 



H. W. F. 



7. Lehrhuch der Allgemeinen Chemie ; by Dr. Wilhelm Ost- 

 WALD. 2 vols. Leipzig, 1902 (Engelmann). — The last section of 

 the second part of volume ii has just appeared. A third part is 

 to appear in the future. This work is by far the most compre- 

 hensive which has yet appeared in the field of physical chemistry 

 and probably comes as near treating the whole subject as it is 

 possible to do. It is to be regretted that volume i and the first 

 part of volume ii are already out of print. h. w. f. 



8. The Spectra of B[ydrogen and Reversed Liyies in the 

 Spectra of Gases ; communicated by Johx Teowbridge. — In a 

 previous paper* I described the spectra produced by powerful 

 condenser discharges through Geissler tubes filled with hydrogen. 

 A fairly continuous spectrum was obtained between the HH lines 

 and the red end of the spectrum which was traversed by reversed 

 lines. In that paper I expressed the hope of being able to obtain 

 quartz tubes. This hope has been realized. Through the kindness 

 of manufacturers! working under the direction and according to 

 the method of Professor Shenstone of Clifton College, England, I 

 have obtained suitable tubes, and the results given by such tubes 

 are so remarkable that they seem worthy of a preliminary paper. 



The tubes are eight centimeters in length ; with a capillary 

 four centimeters in length and about two millimeters in diam- 

 eter. On account of the difficulty of inserting platinum termi- 

 nals in quartz, I had the ends of the tubes ground smooth ; and 

 the glass blower of the laboratory prepared glass bulbs in which 

 suitable electrodes were inserted. These bulbs were luted to the 

 ends of the quartz tubes. In certain cases where metal plates were 

 luted directly to the ends of the quartz tubes I employed silicate 

 of soda as a luting agent ; and after this had hardened I applied 

 on the outside of the joint a hard preparation of pitch and shellac. 



The glass bulbs were covered with other bulbs which allowed 



* This Journal, vol. xiv, p. 1. f Baird and Tatlock, London. 



