May 30, 1889] 



NATURE 



107- 



This department, which seems to enjoy the confidence of the 

 Scotch Office, and all the assistance the importance of the fisheries 

 demands, has now been fully recognized and strengthened by the 

 formation of a Committee of advice and reference, which in- 

 cludes representatives from all the Scotch Universities, and, in 

 addition, an eminent statistician and the distinguished Director 

 of the Edinburgh Science and Art Museum. The Committee, 

 which is expected to advise as to technical and statistical as well 

 as biological and j)hysical questions, consists of Profs. Bayley 

 Balfour, Crum Brown, Dittmar, D'Arcy Thompson, Mcintosh, 

 McKendrick, McWilliam, Traill, and Young ; Sir R. Murdoch 

 Smith, and Mr. G. A. James >n. Those responsible for the 

 formation of this Committee are to be congratulated, not only 

 for the bold and enlightened policy displayed, but also for en- 

 listing the active interest of so many distinguished men in the 

 .Scottish fisheries. The willingness of the members of this Com- 

 mittee to co-operate with the present directors of the scientific 

 work is the best guarantee that their past labours have been 

 appreciated, the best reward for surmounting the many difficulties 

 that have necessarily been met with in initiating and carrying on 

 fishery investigations. 



Mr. Richard Bullen Newton, of the Geological Depart- 

 ment, British Museum, has been presented to an Assistantship 

 of the first class. 



Mr. Melluish succeeds the late Mr. Johnston as Electrician 

 to the Government of India. 



Mr. Haly, Curator of the Colombo Museum, has published 

 a " first report" on the collection of moths in the Museum. It 

 is compiled from Messrs. Coles and Swinhoe's catalogue cf the 

 moths of India and Ceylon, and Mr. Haly has added all that is 

 at present known concerning their local distribution and the 

 times of the year at which the species appear. 



The Johns Hopkins Hospital, Baltimore, was opened on 

 May 7. An address was delivered on the occasion by Dr. 

 Daniel C. Gilman, who spoke eloquently of the close relation- 

 ship between the advancement of knowledge and the progress of 

 charity. 



Messrs. Trub.ver have issued the first number of what ought 

 to be a useful monthly periodical — T/ie Periodical Press Index. 

 The aim of the editor is to present a record of the more 

 important subjects dealt with in periodical literature at home 

 and abroad. As it would become irksome in course of time to 

 consult a monthly index, arrangements are being made for the 

 publication of an additional yearly volume on a plan which will 

 render it unnecessary for students to refer to each part month by 

 month. 



Prof, H. G. Seeley, F.R.S., will conduct the London Geo- 

 logical Field Class to sections on the North Downs, showing 

 Gault and Lower Greensand, on Saturdays in June and on Whit 

 Monday. Communications should be addressed to the Hon. 

 Sec, Mr. R. H, Bentley, 31 Adolphus Road, Brownswood 

 Park, South Hornsey. 



A NEW substance, singular alike in its chemical nature and in 

 its properties, has been discovered by M. Pechard. It is a mixed 

 acid derived from oxalic and molybdic acids, and is therefore 

 termed oxalomolybdic acid. It is a solid, crystallizing in large 

 monoclinic prisms, and forms a well-defined series of salts. 

 Berzelius long ago found that molybdenum trioxide readily dis- 

 solved in a hot solution of oxalic acid, but appears never to have 

 investigated the nature of the reaction. When the molybdic acid 

 has been added almost to saturation the liquid becomes syrupy, 

 and on evaporation yields crystals of the new oxalomolybdic 

 acid, which on analysis give numbers corresponding to the 

 formula C0H2O4 . M0O3 . HjO. The finest crystals are obtained 



by dissolving the viscous mass, formed on evaporating the 

 saturated solution of the acid, in dilute nilrio acid, and allowiog 

 it to evaporate in a desiccator. Oxalomolybdic acid is almost 

 totally insoluble in strong nitric acid, an<l' if an excess of nitric 

 acid be added to a saturated solution of the new acid, smalt' 

 crystals at once separate ; but if dilute nitric acid be employed,, 

 the crystals form more slowly, and are consequently tuuclv 

 larger and more perfect. The crystals dissolve in crfd 

 water, mote rapidly on warming, yielding a colourless and 

 strongly acid liquid. That it is a true mixed acid is shown by 

 the fact that it forms crystalline salts with metals. If a solution* 

 of silver nitrate is added to a warm solution of the acid in- 

 water, a yellow crystalline precipitate of the silver salt,. 

 ^i^Z'fii- M0O3, is thrown down. This salt is ins )luble in 

 water, but, like many other silver salts, is readily dissolved 

 by ammonia. Barium chloride or baryta water precipitate 

 in a similar manner the barium salt CgBa04 . M0O3, in 

 the form of small colourless crystals. The sodium salt, 

 C2Na204 . M0O3 . 5H2O, is readily obtained in good crystals 

 by neutralizing the acid with soda. The crystals of oxalo- 

 molybdic acid, when dry, may be preserved unchanged either 

 in sunshine or in the dark. But, if moist, they quickly be- 

 come coloured blue when exposed to the sun's rays. If cha- 

 racters be written on paper with the solution, they remains 

 invisible in a weak light ; but, when exposed to suo- 

 shine, they rapidly become visible, turning to a deep indigo 

 colour. It is curious that this effect only happens when the 

 solution is spread over paper or other surfaces, for the solution 

 itself may be kept unaltered in the bottle for any length of time, 

 except for a trace of blue at the edge of the meniscus, where, by 

 surface action, a little is spread against the interior glass walls. 

 If a sheet of paper be immersed in a saturated solution of the- 

 acid, dried in the dark, and then exposed behind an ordinary 

 photographic negative, a very sharp print in blue may be 

 obtained by exposure to sunlight for about ten minutes. The 

 colour instantly disappears in contact with water, so that if a 

 piece of this sensitized paper be wholly exposed to sunlight, one 

 may write in white upon the blue ground by using a pen dipped 

 in water. If, however, the paper with its blue markings be 

 exposed to a gentle heat for a few minutes, the blue changes tc 

 black, and the characters are then no longer destroyed by water. 



The Pilot Chart of the North Atlantic Ocean for the month 

 of May shows that the month of April commenced with generally 

 high barometer and moderate weather over the greater part of the 

 trans-Atlantic routes, followed by easterly gales on the 3rd, and 

 continuing in the eastern regions until the nth. On the 7th and 

 15th, areas of high barometer left the American coast, and 

 slowly traversed the ocean, reaching Europe on the 15th and 26th 

 respectively. Several storms visited the American coast, one off 

 Hatteras on the 7th and 8th being of marked severity, causing 

 the water to rise a foot higher than ever known before at Norfolk, 

 and doing great damage both on shore and at sea. There was 

 a great increase of fog, especially off the coast of the United 

 States. A large iceberg was seen on the 9th, in lat. 48° N.,. 

 and long. 44° 40' W. 



A LIMITED number of copies of the fir-t part of the " Biblio- 

 graphy of Meteorology," which has been for many years in coui-se 

 of preparation by the Washington Signal Office, has been issued 

 in a lithographic form by General Greely. It contains 382 quarto 

 pages, and includes all the titles of books and articles bearing 

 upon the subject of tern, erature from the origin of printing to 

 the close of 1881. Similar titles covering the period from j882 

 to 1887 have also been prepared, but are not included in the 

 present volume. The classification of the titles is based upon a 

 scheme furnished by Dr. A. Lancaster, of Brussels, and is ar- 

 ranged under nineteen subdivisions, the arrangement of each. 



