SCIENTIFIC LITERATURE. 



599 



SCIENTIFIC LITERATUEE. 



PHYSICS. 

 'The Proceedings of the Paris Con- 

 gress of 1900 on Methods of Testing 

 Materials' have just appeared in three 

 large folio volumes. The first article by 

 M. Ricour has for its title 'The Molec- 

 ular Constitution of Matter/ but is 

 largely devoted to the discussion of the 

 laws of attraction and to the proper- 

 ties of the ether of space. This ether 

 he imagines to be a sphere whose 

 radius, though great, may perhaps be 

 ultimately found. The distance of our 

 sun from the center of this sphere of 

 ether he finds to be such that light 

 would require 140,000 years to traverse 

 it. The density of the ether he finds 

 to be such that a mass equal in size to 

 our earth would be equal to about one 

 kilogram. While much of the work 

 rests upon hypotheses, the article of 

 Kicour is interesting as showing how 

 the engineer as well as the physicist 

 finally comes to the ether as the ulti- 

 mate source of all energy. If the ether 

 is really a limited sphere, as he sup- 

 poses, the surface of that sphere forms 

 an absolute limit to our knowledge; 

 for should other spheres of ether exist 

 no waves can pass across the empty 

 spaces that separate them from that 

 sphere which contains our universe. 



MOSQUITOES A?fD MALARIA. 



Dr. Leland 0. Howard, the ento- 

 mologist to the United States Depart- 

 ment of Agriculture, has just given us 



a little book on 'Mosquitoes' (McClure, 

 Phillips & Co.) that is peculiarly well 

 timed and important. Dr. Howard has 

 studied his subject for many years; 

 primarily, in the past, to devise 

 methods for the local control of an 

 annoying pest; but recently, since the 

 relation of some of the genera to the 

 spread of malarial and other febrile 

 diseases has been established, to ascer- 

 tain their peculiarities of habit and de- 

 velopment. 



Public interest in the newspaper and 

 magazine accounts has been so marked 

 that a book like this which gives in 

 concise form and with scientific ac- 

 curacy just what is known of the rela- 

 tion between disease and insects must 

 be especially useful to correct the mis- 

 information gaining currency among 

 the general public. Dr. Howard gives 

 us in detail the life history of our 

 commonest species; both Culex, which 

 is an annoyance merely, and Anopheles, 

 which is the intermediate host for the 

 organism producing malarial diseases 

 in man. The breeding places of each 

 are discussed and the measures which 

 may be adopted to do away with them. 

 A very complete account is given of the 

 experiments which link the Stegomyia 

 fasciata with yellow fever, and a brief 

 statement shows the relation between 

 Culex ciliaris and Filariasis. A chap- 

 ter on classification shows fairly well 

 what is known of our American species 

 and gives some indication of what yet 

 remains to be learned. 



