98 Scientific Intelligence. 



( Helsingfors, 1907 ) containing an account of a case of ovogenesis 

 in which certain of the egg cells, possibly those normally destined 

 to produce the male sex, are absorbed by the more vigorous 

 (female ?) cell's, thus producing a preponderance of female indi- 

 viduals, w. e. c. 



IV. Miscellaneous Scientific Intelligence. 



1. Artificial Daylight for Use loith the Microscope ; by Fred. 

 Eugene Weight. (Communicated from the Geophysical Labora- 

 tory.) — For microscopic work with rocks, and especially with arti- 

 ficial products, daylight on dark winter days is a factor much to be 

 reckoned with, and the want of a good substitute for it has long 

 been felt by the writer. Many different kinds of artificial light 

 are available, but the results obtained by their use have not, on 

 the whole, been satisfactory. The natural colors of mineral sec- 

 tions, and also interference colors, appear abnormal and unnatural 

 in artificial light, the illumination of the field is not even, and 

 good interference figures on small plates are not as a rule obtain- 

 able. Recently, however, the following illuminating device has 

 been tried and has proved so satisfactory that it deserves brief 

 mention. 



The source of light is an acetylene burner fed by a J. B. Colt 

 generator No. 102, and placed at the focus of a large condens- 

 ing lens of about 20 cm focal length. Compared with daylight, 

 acetylene light is slightly too strong in yellow, bat by passing the 

 parallel rays from the condenser lens through a pale blue cobalt 

 glass plate of the proper intensity, this difficulty is eliminated 

 and the field appears white and the colors, both natural and inter- 

 ference colors, are normal and correct. In certain tones, very 

 slight differences can be -detected, but these are of an order 

 noticeable in different sections of the same substance and are not 

 serious. With this arrangement, acetylene light, condenser lens 

 and pale blue glass ray filter, the observer has at hand a source of 

 illumination which is practically identical in its effect with day- 

 light, and which is available at any moment. 



2. Ion. A Journal of Ulectrotonics, Atomisties, lonology, 

 Radio-activity and Raumchemistry. Edited by Charles H. 

 Walter* Vol. I, Fasc. 1. Pp. 80. November, 1908. London 

 (16 Heathfield Gardens, Turnham Green, W.). — An unavoidable 

 result of the recent development of science along special lines has 

 been the establishment of many new journals of more and more 

 restricted field. This multiplication of periodicals is in many 

 respects an admirable thing, having a decidedly stimulating effect 

 upon the workers immediately interested, but, at the same time, 

 it has its drawbacks and adds a somewhat heavy burden upon 

 science in general. In Germany, in particular, these specialist 



* The name of Frederick Soddy appears on the title page as an editor-in- 

 chief, but in Nature for Nov. 26, Professor Soddy announces that he has 

 "withdrawn from all connection with the journal." 



