612 



SCIENCE 



[N. S. Vol. XLIV. No. 1139 



products of the bacterial growth. The tumors 

 though small have been obtained repeatedly on 

 several kinds of plants and there seems to be 

 no reasonable doubt that they are due to the 

 fleeting chemical stimulus which I have ap- 

 plied. Judging from my experiments, which 

 have been continued for some months, the 

 mechanism of tumor growth appears to be 

 wholly one of changed osmotic pressures 

 brought about by the metabolism of the tumor 

 parasite. A full paper will be published as 

 soon as I have finished studying my serial sec- 

 tions and have had time to make suitable 

 photomicrographs to illustrate it. 



Erwin F. Smith 

 IT. S. Department op Agriculture, 

 Washington, D. C, 

 October 17, 1916 



QUOTATIONS 



THE OPTICAL INDUSTRY IN FRANCE 



A series of articles by various authors has 

 recently been appearing in the Revue generate 

 des Sciences on the methods to be adopted for 

 the development of French trade after the war. 

 Amongst these have appeared two articles 

 (May 30 and June 13) by M.-. A. Boutaric on 

 the French optical industry and its future. 



He points out that before the Napoleonic 

 wars France had been dependent on England 

 for its optical glass, and it was as a result of 

 the British blockade that its manufacture was 

 commenced in France. 



At the present time the house of Parra-Han- 

 tois manufactures practically all the special 

 optical glasses made by Schott and Co., and 

 the French makers undoubtedly are more suc- 

 cessful than their competitors in the manufac- 

 ture of the glass discs required for very large 

 astronomical mirrors and objectives. In 

 every branch of optical science French 

 physicists have invented instruments and meth- 

 ods for testing their qualities, but the French 

 manufacturers have not done themselves jus- 

 tice by an efficient catalogue propaganda. M. 

 Boutaric, when referring to the firm of Zeiss, 

 mentions especially that it " has surrounded 

 its products with a scientific propaganda." He 



shows how severe the German competition in 

 microscopes was before the war, although there 

 are two good French makers — Nachet and 

 Stiassnie. The metallurgical microscope of Le 

 Chatelier has been developed by Pellin with 

 considerable success. The polarimeter in its 

 present commercial form was developed by the 

 French makers Soliel and Laurent, and is es- 

 sentially a French instrument, yet the Ger- 

 man houses have almost obtained a monopoly 

 in the sale of the instrument outside France. 



The manufacture of binoculars is the most 

 successful of all the French optical industries, 

 several large firms (Balbreck, Baille-Lemaire, 

 Societe francaise d'Optique, Societe des Lune- 

 tiers, etc.) being employed in their manufac- 

 ture. As showing the large quantity of optical 

 glass used in these glasses, it is stated that the 

 Societe des Lunetiers alone use about 200,000 

 kilos of glass annually. 



Although French makers showed several 

 prism binoculars of the Porro type at the 1867 

 Exhibition, yet the manufacture of these 

 glasses passed almost entirely to Germany. 

 ISTow, however, glasses equal to the best Ger- 

 man models are being made in France in large 

 numbers for her army and those of her Allies. 

 The original supremacy of the French photo- 

 graphic lens has passed away, because, in the 

 opinion of M. Boutaric, the French makers did 

 not use the new glasses and modern grinding 

 methods, nor sufficiently avail themselves of 

 skilled technical knowledge. H. J. Richard 

 has developed with great skill and success a 

 stereoscopic camera, the " Verascope," and also 

 a very rapid camera shutter, but the majority 

 of the cameras used in France have been im- 

 ported. The kinematograph, the invention of 

 a Frenchman, Professor Marey, has been car- 

 ried to a high state of perfection by the firms 

 of Lemaire, Pathe and Gaumont. To a certain 

 extent France is dependent on outside sources 

 for kinematograph film, but, on the other 

 hand, she exports finished printed film to the 

 annual value of £600,000. The lighthouse in- 

 dustry, built on the theoretical work of Fres- 

 nel, is a successful one, although it has had to 

 face keen competition from English and Ger- 

 man makers. 



