May 8, 1879] 



NATURE 



45 



at one time, on account of the comparative safety attending its 

 storage and the necessary manipulation of it. Moreover, it has 

 been well established by experiments of many kinds carried out 

 on a coasiderable scale, as well as by accurate scientific observa- 

 tions, that the detonation of vret gun-cotton is decidedly sharper 

 or more violent than that of the dry material ; a circumstance 

 which affords an interesting illustration of the influence exerted 

 by the physical condition of the mass upon the facility .with 

 which detonation is transmitted from particle to particle. In 

 the determinations made by means of the Nobel chronoscope, 

 if the velocity with which detonation is transmitted along layers 

 trains of gun-cotton and nitro-glycerine, the lecturer has 



eluded experiments with gun-cotton containing different pro- 

 portions of water. When the material contained 15 per cent, 

 of the liquid, some indications were obtained that the rate of 

 transmission of detonation was a little higher than with dry gun- 

 cotton ; the difference was very decidedly in favour of wet gun- 

 cotton, when the latter was thoroughly saturated with water. 

 The air in the masses of compressed gun-cotton being replaced 

 entirely by the comparatively incompressible body, water, the 

 particles of explosive are in a much more favourable condition 

 to resist displacement by the force of the detonation, and hence 

 they are more readily susceptible of sudden chemical disintegra- 

 tion. Moreover, the variations in the rate of travel of detona- 

 tion in dry gun-cotton, resulting from differences in the compact- 

 ness or rigidity of different masses of the material, are very 

 greatly reduced, if not entirely eliminated, by saturating the 

 disks with water, and thus equalising their power of resisting 

 motion by a sudden blow. 



Another striking illustration of the influence which the physi- 

 cal character of an explosive substance exercises over its suscep- 

 tibility to detonation and the degree of facility with which its 

 full explosive force is developed, is furnished by one of the most 

 recently devised, and one of the most interesting of existing, 

 ■xplosive agents. 



Twelve years ago, soon after the process of producing com- 

 pressed and granulated gun-cotton had been elaborated by the 

 lecturer, it occurred to him to employ these forms of gun-cotton 

 as vehicles for the application of nitro-glycerine. A consider- 

 able proportion of the liquid was absorbed by the parous masses 

 of gun-cotton, and a nitro-glycerine preparation analogous in 

 character to dynamite was thus obtained. The absorbent was 

 ia this case a violently explosive body instead of an inert solid 

 as in dynamite, but the quantity of nitro-glycerine in a given 

 weight of the preparation (to which the name of glyoxilin was 

 given), was considerably less than in the kieselguhr-preparation ; 

 hence the latter was nearly on a point of equality with it, in 

 regard to power, as an explosive agent. 



( To be continued. ) 



NOTES FROM RUSSIA 



Geography AND Anthropology. — At the last meeting, 

 April 23, of the Imperial Russian Geographical Society, M. 

 Sreznefeky, the Secretary, communicated his monthly report on 

 the work of the Society. This consisted in equipping three 

 expeditions in which the Society intends to take part, and its 

 participation in the Anthropological Exhibition of Moscow. 

 The first expedition is the cruise of the steamer Nordenskjold, 

 equipped by the well-known merchant of Siberia M. Sibiriakoff, 

 for the relief of Prof. Nordenskjold in the Vega. It will proceed 

 from Malmb direct to Yokohama, Behring Strait, and beyond. 

 According to the request of M. Sibiriakoff the Society appointed 

 to accompany the expedition M. A. W. Grigorieff, an accom- 

 ))lished botanist, known for his dredging work in the White 

 .Sea, where he collected very interesting specimens of marine 

 fauna with deep soundings and temperature observations, by 

 means of a Negretti and Zambra deep-sea thermometer. He 

 proceeds to Malmo to join the expedition, with a Dent chrono- 



iieter from the Society, and a complete provision for zoological 



oUections, and a sufficient provision of alcohol. 



The second expedition is sent out by the Ministry of ^Public 

 Works, for the exploration of the old bed of the Amu-daria 

 (Usboi), and to investigate the possibility of turning the river to 

 the Caspian ; it will be under the direction of Major-General 

 A. T. Gloukhofskoi, an experienced traveller in Central Asia. 

 The Society sends two Fellows with the expedition, a geologist. 

 Prince Sedroiz, and the economist, N. A. Majef, the manager of 



he Turkestan Newsj a collector of varied statistical materials 



in Turkestan. The third expedition, of a private character is 

 to explore for a railroad from Orenburg to Tashkent, and the 

 possibility of navigating with steamers the Sir and Amudaria. 

 By order of the Emperor a sum of 5,000 roubles is placed at the 

 disposal of the Society. 



Tlie Anthropological Exhibition was opened in Moscow on 

 April 15, under the superintendance of the Society, which has 

 sent a great number of valuable objects of an ethnological 

 character, with craniological collections and prehistorical speci- 

 mens, tumuli excavations, and a valuable collection belonging 

 to thej^Czarevich. All these collections were arranged by M. 

 Sreznefsky, the Secretary of the Society, who was sent as its 

 representative to the opening of the exhibition. The aim of 

 this exhibition is : (l) To contribute to the development of 

 anthropology as a science. (2) The foundation of an anthropo- 

 logical museum for the teaching of anthropology in the University 

 of Moscow. (3) To popularise the sciece. 



The exhibition is divided into sections — prehistorical, anthro 

 pological, medico-anthropological, photographical, ethnographi- 

 cal, the history of Russian types. 



At the end of the meeting of the Society M. Alenitzin com- 

 municated his paper on the history of the Amu-daria question ; 

 he criticised the different opinions on the possibility of turning 

 the Amu-daria into the Caspian, and doubted whether this ques- 

 tion could be resolved practically and in a positive manner. 



A. LOMONOSSOFF 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE 



The Council of the Society of Arts having received an appli- 

 cation from the City and Guilds of London Institute for the 

 Advancement of Technical Education, offering to take charge of 

 the technological examinations established by this Society in 

 1873, and carried on to the present time, have resolved to 

 transfer these examinations to the charge of the Institute. The 

 Council have also ascertained that the Science and Art Depart- 

 ment will assist the City Institute in conducting the examina- 

 tions, in the same way as it has hitherto assisted the Society of 

 Arts. The technological examinations for the present year will, 

 therefore, be carried on under the direction of the Institute, and 

 all communications on the subject should be addressed to the 

 Hon. Secretaries, City and Guilds of London Institute, Mercer's 

 Hall, E.C. 



The following is the result of the recent examination for the 

 Public Schools Prize Medals of the Royal Geographical Society : 

 Physical Geography (examiner John Ball, F.R.S.), gold medal, 

 Matthew George Grant ; silver medal Frank Taylor Sharpe, both 

 of Liverpool College. Honourably mentioned : E. G. Harmer, 

 University College School ; H. LI. Smith, Bristol Grammar 

 School ; F. S. Carey, Bristol Grammar School ; A. T. Mac- 

 Conkey, Liverpool College. Political Geography (examiner 

 Canon Tristram, F.R.S.), gold medal, David Bowie, Dulwich 

 College. Silver medal, Claude L. Bickwell, Harrow School. 

 Honourably mentioned, J. F. Naylor, Dulwich College ; 

 W. H. D. Boyle, Eton ; A. D. Rigby, Liverpool College ; 

 Theod. Brooks, London International College ; R. A. Fawcett 

 and A. C. Painter, of Clifton College. 



On May i an interesting ceremony took place at St. Barbe, 

 the principal free institution at Paris. Two bodies of pupils 

 were marched under the direction of teachers ; the first was 

 going to the Gare du Nord in order to come to London and spend 

 six months in a corresponding English institution to learn the 

 English language ; the other went to the Gare de I'Est to pro- 

 ceed to Germany. These pupils have already learned foreign 

 languages in Paris. They are placed under the supervision of 

 professors, so that the usual routine of their studies for French 

 honours should not be interrupted in any way. 



SCIENTIFIC SERIALS 



Annalen der Fhysik und Chemie, No. 3. — In view of contradic- 

 tory results got by Sir W. Thomson and M. Le Roux, with 

 regard to the thermoelectric behaviour of stretched wires, Herr 

 Cohn has made a number of experiments, here described in an 

 inaugural dissertation. He finds that the intensity of the thermo- 

 current between stretched and unstretched wire of the same 

 metal, depends (apart from all permanent properties), not only 

 on the present tension of the former, but also, in very different 



