July 4, 19 18] 



NATURE 



35' 



line, acts as a cement, and has both setting and bind- 

 ing properties. A greenish-blue pigment examined was 

 composed of azurtte, a hydrated carbonate of copper; 

 whilst the green pigment was a mixture of malachite^ 

 azurite, and clay. The grey was limestone mixed 

 with charcoal or carbon, and the black was a carbon 

 black, composed of charred wood or burnt bones. It 

 has been generally assumed that the Egyptians used 

 white of egg as a binder for their pigments, but Mr. 

 Toch could find no trace of any albuminous binder in 

 the specimens submitted to him ; they did, however, 

 show evidence of the use of glue or gelatin. The 

 pigment in two paint-pots, evidently thrown away by 

 the workmen, was found to be haematite mixed with 

 limestone and el^y. 



A REPORT of Prof. W. J. Pope's recent presidential 

 address to the Chemical Society, which is comparable 

 in importance with the late Prof. Meldola's address of 

 eleven years ago, is printed in the April issue of the 

 society's Journal. Prof, Pope commences his address 

 — entitled " The Future of Pure and Applied Chemis- 

 try "—by pointing out that the last three years have 

 dissipated for ever the fallacy that British chemists 

 cannot excel in applied organic chemistry. In fact. 

 Great Britain, which in 19 14 had no resources for 

 their manufacture, is now a larger producer of explo- 

 sive, pharmaceutical, photographic, and other essential 

 chemicals than Germany. The fact that science is 

 ' unvocative has prevented the people from realising 

 that the discoveries of Young, Davy, and Dalton at 

 the beginning of the nineteenth century had more 

 influence than the Napoleonic wars. The whole his- 

 tory of Europe for the last century was made Within 

 ^the laboratories of the Royal Institution. The 

 greatest incentive to political change is the desire to 

 increase the amenities of life, and research in pure 

 science has for a hundred years been the greatest 

 influence in this direction. Prof. Pope strongly urges 

 that the various chemical societies should set up a 

 joint council for the consideration of national ques- 

 tions in which chemical interests are concerned, and 

 suggests for its consideration the correlation of the 

 dve interests with the synthesis of pharmaceutical and 

 photographic products, the development of natural 

 colouring matters, and the study of patent law. 



Some interesting examples of the' work accomplished 

 by the Salvage Section of the Admiralty are given in 

 r^ Engineering for June 21. Since October, 1915, down 

 to the present time about four hundred ships have 

 been salved by this department. A large proportion of 

 these ships, some of which are of high carrying 

 capacity, has been repaired, refitted, and put in com- 

 mission afresh. On account of the comparative 

 shortage of shipping it is worth while at the present 

 time to salve practically every sunken ship, whereas 

 before the war many would have been left to their 

 fate on account of the cost of the operation exceeding 

 the value of the ship. One of the great aids to 

 salvage operations is the submersible electric-driven 

 motor-pump, some types of which can deliver 500 tons 

 of water per hour to a height of 75 ft. to 80 ft. One 

 of the examples quoted is that of a vessel carrying 

 a cargo of foodstuffs to the combined value of more 

 than 3,ooo,oooi. After being torpedoed, she was 

 taken in tow by the Section's tugboats, but sank 

 before she could be left high up on the beach. Elec- 

 trically driven submersible pumps were put down in 

 ^' the stokeholds and divers established communication 

 ' betw-een the flooded holds and the stokeholds, .\fter 

 '' making the parts thus involved watertight on the 

 outside the pumps were started, and the vessel, being 

 thus lightened, could be drawn higher up on the 

 ach, when similar operations were effected in the 



ND. 2540, VOL. 1 01] 



lower submerged quarters. The vessel was ultimately 

 floated off and repaired. ^. , 



In a recent issue of the Zeitschrift fiir angewandtti 

 Chemie is described a process (patented in Ger- 

 many) for spraying metals on to any kind of 

 surface, using metal melted in an electric arc 

 and blown by means of gas-jets on to the 

 surface to be covered. The metal to be sprayed 

 forms one of the electrodes of the arc, and the gas- 

 jets are directed so as to strike the sides of the metal 

 electrodes without impinging on the arc and blowing 

 it out. If the arc is produced between two electrodes, 

 one being metallic, and a stream of non-oxidisable 

 gas is directed on to the electrode, portions of the 

 electrode that are melted will be carried away in the 

 form of a fine spray, and may be deposited on any 

 surface on which they impinge, thus forming a 

 metallic skin on it. Suitable control apparatus is 

 provided to allow for the wear of the electrodes. 



We have received a Classified List of Publications 

 I of the Carnegie Institution of Washington, dated 

 December, 1917. It is stated that copies of each 

 publication, except the Index Medicus, are sent 

 gratuitously to each of the greater libraries of the 

 world, while the remainder of the edition is to be 

 sold at prices sufficient only to cover the cost of 

 publication and postage. Among the volumes pub- 

 ! lished by the institution in 1916 and 1917 we notice : — 

 I In astronomy, a revision of Ulugh Beg's Persian 

 ! Catalogue of Stars by E. B. Knobel ; in mathematics, 

 a Sylow Factor Table of the first twelve thousand 

 I numbers by H. W. Stager; in chemistry, "The Inter- 

 1 ferometry of Reversed and Non-rever-sed Spectra," by 

 Carl Barus; in terrestrial magnetism, "Ocean Mag-' 

 netic Observations, 1905-16," by L. A. Bauer; in 

 I palaeontology, "American Fossil Cycads," by G. R. 

 Wieland, and "The Cqal Measures Amphibia of 

 ' North America," by Roy L. Moodie; in embryology, 

 two new volumes of the " Contributions to Embryo- 

 logy," by various authors; in evolution, " Studies of 

 Inheritance in Guinea-pigs and Rats," by W. E. Castle 

 and S. G. Wright, ' Gonadectomy in Relation to the 

 Secondary Sexual Characters of some Domestic 

 Birds," by H. D. Goodale, and "Sex-linked Inherit- 

 ance in Drosophila," bv T. H. Morgan and C. B. 

 Bridges; in botany, "Plant Succession," by F. E. 

 Clements ; and in zoology, a new volume of papers 

 from the Department of Marine Biology of the Car- 

 negie Institution. It will be seen that the works 

 recently published by the institution belong, as in 

 former years, to many different branches of science. 

 The complete list contains about 264 volumes pub- 

 lished since 1903, with short descriptive notes on most 

 of these publications. 



Messrs. Blackie and Son, Ltd., will shortly pub- 

 lish "Medicinal Herbs and Poisonous Plants," by 

 Prof. David Ellis, of the Royal Technical College, 

 Glasg^ow. 



OUR ASTRONOMICAL COLUMN. 



A New Asteroid of the Trojan Group.— A fifth 

 member of this group has been discovered by Wolf. 

 It has at present only the provisional designa- 

 tion CQ. The following elements are given in 

 Ast. Nach., No. 4945 : — Epoch 1917, September 

 24.5, G.M.T., M 83° 18' 55", (o 329° 32' 38", 

 51 300° 41' 27^ t 8° 51' 26% f 6° 46' 53", M 294-427*, 

 log a 0720686. CQ and Patroclus are about 60° behind 

 Jupiter in longitude, while Achilles, Hector, and Nestor 

 are 60° in front of Jupiter. The value of fi for each 

 of them oscillates about 5" on each side of the value 

 for Jupiter 299*, the period of an oscillation being 



