1886.] 



MICROSCOPICAL JOURNAL. 



37 



The catalogue is sold for ten cents, and 

 we would advise all microscopiststo secure 

 copies. 



— The obelisk which stands in Central 

 Park, New York City, has been seriously 

 affected by the severe climate, and disin- 

 tegration of its surface was proceeding so 

 rapidly that some method of protection 

 was considered necessary. A preparation 

 of paraffin has been applied for the pur- 

 pose. Mr. P. H. Dudley examined the 

 shaft during the treatment and found the 

 surface very porous and full of minute 

 fractures. Beneath the superficial flakes 

 he found a growth of green cells, rod- 

 shaped, with straight sides and slighdy 

 convex ends, 2 to 6 micro-millimetres in 

 length. He has been unable to find a 

 description of the plant. An account of 

 the process of protecting the shaft, as well 

 as some remarks of Mr. Dudley, is given 

 in the Transactions of the N. Y. Academy 

 of Sciences. 



— We are pleased to receive a copy of 

 a very creditable new publication, the 

 Jotirnal of the Trenton Natural History 

 Society, the first number of which was 

 issued in January, published by the 

 Society at Trenton, N. J. The number 

 before us is full of interesting articles on 

 natural history, not too technical to attract, 

 but well adapted to general reading. The 

 Society is to be congratulated upon the 

 first number, and we trust the effort 

 will receive the well merited support of 

 many subscribers. Dr. A. C. Stokes has 

 an article in this number entitled Notes on 

 Peridinium and other Infusoria. 



— The following process for preparing 

 a dead black surface on brass, for optical 

 instruments, etc., is given by T/w Loco- 

 motive: — ' Take two grains of lamp- 

 black, put it into any smooth, shallow 

 disk, such as a saucer or small butter- 

 plate, add a little gold size and thor- 

 oughly mix the two together. Just enough 

 gold size should be used to hold the 

 lampblack together. About three drops 

 of such size as may be had by dipping the 

 point of a lead pencil about half an inch 

 into the gold size will be found right for 

 the above quantity of lampblack ; it 

 should be added a drop at a time, how- 

 ever. After the lampblack and size are 

 thoroughly mixed and worked, add 

 twenty-four drops of turpentine, and 

 again mix and work. It is then ready for 

 use. Apply it thin with a camel's-hair 

 brush, and when it is thoroughly dry, 

 the articles will have as fine a dead black 



as they did when they came from the 

 optician's hands.' 



— General John Newton, Chief of En- 

 gineers, United States Army, originator of 

 the plan and director of the work, has 

 prepared a complete account of the 

 operations for the removal of the obstruc- 

 tions at Hell Gate, from their beginning 

 to the explosion of Flood Rock, in Octo- 

 ber last, which appears with full and 

 new illustrations as the leading article in 

 the February number of ' The Popular 

 Science Monthly.' 



— Mr. J. Trail Taylor, who for fifteen 

 years occupied the editorial chair of The 

 British Jom'nal of Photography, having 

 completed the term of his literary engage- 

 ment in America, where he has edited for 

 a number of years our valued contem- 

 porary. The Pliotographic Times, has 

 returned to England to resume his old 

 position, and will, as in times of yore, be 

 glad to receive all friends of the Journal, 

 from home or abroad, at the editorial 

 rooms, 2 York street, Covent Garden. 

 We congratulate The British Journal 

 upon once more acquiring the services of 

 such an able editor and accomplished 

 writer. 



— At the recent meeting of the Ameri- 

 can Public Health Association, Dr. George 

 M. Sternberg received the only first prize 

 that was given, for an essay on disinfec- 

 tion and individual prophylaxis against 

 infectious diseases. This prize was offered 

 by Mr. Henry Lomb, of Rochester, N. Y., 

 who provided the sum of |;2,8oo to be 

 distributed in prizes for essays on speci- 

 fied subjects. Only |;i,ioo was awarded 

 in all, and most of the remainder has 

 been offered by Mr. Lomb to be awarded 

 for essays this year. 



— Prof. D. S. Holman has been pho- 

 tographing infusoria instantaneously with 

 the oxy-hydrogen light. He has success- 

 fully photographed the living Amoeba in 

 its various forms, with exposures said to 

 be about the hundredth of a second, with 

 a magnification of 250 diameters. Lan- 

 tern transparencies were made from the 

 negatives and the images thrown upon a 

 screen at the Franklin Institute, showing 

 the organisms magnified ten thousand 

 diameters. The instantaneous photograph- 

 ing of infusoria was successfully done 

 years ago, but at the present moment we 

 are unable to recall the facts with sufficient 

 clearness to give any further particulars. 



— In a recent leaure on ' Matter, In- 

 cluding Radiant Matter,' by A. E. Outer- 



