THE PROGRESS OF SCIENCE. 



57i 



tolerable state of affairs to which the 

 Russian press and people must submit. 

 Russian newspapers are of two classes, 

 censored and uncensored. The former 

 must show everything that is printed 

 to a local censor beforehand, the latter 

 are subject to the minister of the inte- 

 rior, who suppresses or punishes them 

 as he sees fit. It is said that the condi- 

 tions are not quite so bad as they were, 

 but a ' confidential ' letter of instruc- 

 tions sent to the uncensored papers 

 from the ministry of the interior on 

 the twenty-second of last July gives 

 striking information as to the limita- 

 tion imposed on freedom of speech. 

 Among the large number of subjects 

 regarding which it is forbidden to 

 publish news or criticism we quote the 

 following coming within the scope of 

 this journal: 



Information and articles concerning 

 disorders in the higher educational es- 

 tablishments, whether secular or cleri- 

 cal, and disciplinary punishments 

 inflicted on those taking part in such 

 disorders, . . . and, in general, all 

 news relating to the internal life of 

 these institutions, except when the com- 

 petent educational authority has con- 

 sented to Buch publication. 



Information concerning disorders, in 

 our factories and industrial works, or 

 any other breaches of public order and 

 tranquility, except when permission for 

 publication has been given by the higher 

 police authorities. 



Information concerning the appear- 

 ance of epidemic diseases among the 

 population, or the spread of the plague 

 in Russia and the adjacent countries, 

 except when permission for publication 

 has been given by the medical depart- 

 ment of the Ministry of the Interior. 



Historical and critical disquisitions, 

 articles and documents, printed in 

 specialist or strictly scientific journals 

 or other works, in cases where such 

 articles, etc., serve an exclusively sci- 

 entific purpose, and where, by reason 

 of their contents, their distribution 

 among a wide circle of readers might 

 lead to undesirable results. 



We shall look forward with interest 

 to learn whether the censor discovers 

 this note and cuts it out of the copies 

 of the Monthly going to subscribers 

 in Russia. 



MILEY'S COLOR PHOTOGRAPHY. 



Professor W. G. Brown, of the 

 University of Missouri, brought to the 

 attention of the Chemical Section of 

 the American Association for the Ad- 

 vancement of Science, at the recent 

 Washington meeting, a new method of 

 color photography of considerable in- 

 terest, due to M. and H. M. Miley, 

 of Lexington, Va. Two photographs 

 were shown a copy of Rembrandt 

 Peale's Washington in the uniform of 

 a colonial officer, and a plate of peaches. 

 The process is a three-color film one, 

 in which the essential modification of 

 existing processes is the use of pig- 

 mented gelatine films in place of 

 stained ones. 



In making photographs by this 

 method, three negatives are taken in 

 colored light, the light being obtained 

 by passing ordinary light through a 

 medium of proper color interposed be- 

 tween the lens and the plate, usually 

 a screen of colored glass or some color- 

 ing matter placed between sheets of 

 thin glass. One negative is taken 

 through a red screen, a second through 

 a green screen and a third through a 

 violet screen. The colors, red, green 

 and violet, used for the screens should 

 be such as transmit rays falling within 

 a limited portion of the spectrum. The 

 photographic plates used for the nega- 

 tives must be adapted to the color of 

 the light to which they are exposed; 

 for the negative exposed to the red 

 light an orthochromatic plate stained 

 with cyanin solution, for that to the 

 green light an unmodified orthochro- 

 matic plate and for violet light an 

 ordinary gelatin-silver-bromid plate is 

 used. From the negatives obtained posi- 

 tives are. made of carbon tissue (bi- 

 chromated gelatin pigment paper). 

 The carbon tissue, perhaps better, 

 pigment tissue, used with the red 

 light negative is charged with an 

 inalterable blue pigment, the blue be- 

 ing the complementary of the red used 

 in the production of the negative. The 



