Page:Popular Science Monthly Volume 62.djvu/577

Rh 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 interior, who suppresses or punishes them as he sees fit. It is said that the conditions are not quite so bad as they were, but a 'confidential' letter of instructions sent to the uncensored papers from the ministry of the interior on the twenty-second of last July gives striking information as to the limitation 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 establishments, whether secular or clerical, 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 competent educational authority has consented 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 appearance 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 department 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 scientific 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 going to subscribers in Russia.

of the University of Missouri, brought to the attention of the Chemical Section of the American Association for the Advancement of Science, at the recent Washington meeting, a new method of color photography of considerable interest, 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 pigmented 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 between the lens and the plate, usually a screen of colored glass or some coloring 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 negatives 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 orthochromatic plate and for violet light an ordinary gelatin-silver-bromid plate is used. From the negatives obtained positives are. made of carbon tissue (bichromated 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 being the complementary of the red used in the production of the negative. The