CHEMICAL SCIENCE. 199 



by Mr. Joubert are some monochrome photographs on earthenware 

 tiles, manufactured by Messrs. Minton and Co. 



PHOTOGRAPHY AND FLUORESCENCE. 



Professor Faraday has exhibited to the Eoyal Institution Pho- 

 tographs of fluorescent substances which had been prepared by Dr. 

 J. H. Gladstone. He reminded the members present of experiments 

 they had seen in that theatre showing that certain bodies, as bi- 

 sulphate of quinine, emit a beautiful bluish light when they are 

 exposed to the most refrangible rays of the spectrum, and are also 

 phosphorescent. Several of these are white or colourless to look at 

 under ordinary circumstances ; but it had occurred to Dr. Gladstone 

 that on account of their lowering the refrangibility of the chemical 

 rays they would perhaps not produce so great a photographic effect 

 as other white substances. He had, therefore, drawn various devices 

 in quinine salt, esculine from horse-chestnut bark, comenamate of 

 potash, and other fluorescent substances on white paper, and had had 

 the apparently white sheet photographed. The devices all came out 

 dark, as was seen in the specimen exhibited ; and, more than that, 

 on a sheet of paper coloured blue with cobalt were fixed letters cut 

 out of white paper and steeped in the fluorescent solutions above 

 mentioned. When this sheet was photographed the blue paper was 

 found to have a much greater chemical effect than the white letters, 

 which, therefore, appeared in the positive photograph dark on a 

 light ground. — Illustrated London News. 



THE NEOMONOSCOPE. 



M. P. A. A. Beau has patented a Neomonoscope, or apparatus 

 for viewing photographic and other like pictures. This is constructed 

 with one glass or several glasses superposed for the purpose of ob- 

 taining a similar effect to that derived from viewing pictures in or 

 through a stereoscope. The monoscope is a pyramidal or conical- 

 shaped case, with a part of one of the sides removed to admit light. 

 The glass is fitted in the top of the apparatus, and, in some cases, 

 flaps for forming when raised a dark chamber between the eye and 

 the glass are added. The bottom of the apparatus is made to slide to 

 admit of its being entirely removed in order to view transparent 

 objects, or others apart from the apparatus itself. The sides of the 

 apparatus are either made rigid or to fold. — Mechanics' Magazine. 



PHOTOGRAPHIC OBSERVATION OF THE SOLAR ECLIPSE, JULY 18, 1860. 



Mr. John Spiller, F.C.S., has communicated to the Philosophi- 

 cal Magazine, No. 132, a description of the Photographic Represen- 

 tation of the Solar Disc, as it appeared from the station of the equa- 

 torial telescope of the Royal Artillery Institution, Woolwich, under 

 the several phases of the particular Eclipse ; the successful termina- 

 tion of the day's labour resulting in the production of 23 photo- 

 graphic impressions of the phenomenon. 



The telescope, with its portable stand provided with means of ad- 



