February i i, 1892] 



NA TURE 



351 



plex conditions produced by the march of various types of 

 pressure from one part to another is a necessary prelude of 

 long-time weather predictions for large areas. 



The Mediterranean Naturalist for January prints some good 

 notes, by Mr. J. J. Walker, R,N., on ants' nest beetles at 

 Gibraltar and Tangier, with especial reference to the Hisperidse. 

 The search for ants' nest Hister is a somewhat troublesome 

 employment, as only about 2 or 3 per cent, of the ants' nests 

 contain the beetle. Mr. Walker, however, thinks " it is a pretty 

 sight, and one wliich compensates for a great deal of strain to 

 the eyes, as well as to the back, to see a Sternocivlis or Eretmotus 

 lying motionless among the hurrying crowd of ants, and then, 

 suddenly developing an amount of leg quite surprising in so small 

 a creature, marching off daintily on the tips of its toes (or rather 

 tarsi) with a ludicrous resemblance, in its gait and appearance, 

 to a tiny crab." The comparatively weak mandibles of the ants 

 are ineffective against the hard armour and tightly packed limbs 

 of the beetles, which devour the helpless brood with impunity. 

 Mr. Walker has more than once taken S. acutanguhis with a 

 half-eaten larva in its jaws, and they are usually to be found 

 clinging to the masses of larvae where these lie thickest. On the 

 other hand, he once (but once only) saw an ant take up a 

 S. arachnoides in its mandibles and carry it off into a lower 

 gallery of the nest ; but this may have been done under the 

 influence of alarm, the frightened ant seizing on the first object 

 that came in its way. 



A VALUABLE map is issued with the current number of the 

 Proceedings of the Royal Geographical Society. It has been 

 constructed by Mr. W. J. Turner, in accordance with instructions 

 given by the Hon. George Curzon, who explains in a memo- 

 randum various matters connected with the work. The map, 

 with the memorandum and an index to the positions of places, 

 is to be bound in a handy form and published separately. 



An interesting paper on the GranChacois contributed by Mr. 

 J. Graham Kerr to the current number of the Scottish Geographical 

 Magazine. Mr. Kerr visited the Gran Chaco in connection with 

 the recent Pilcomayo Expedition. Most writers on the region 

 have praised it in unmeasured terms ; and this judgment, con- 

 fined to the zone bordering the fresh- water rivers, is declared by 

 Mr, Kerr to be perfectly just. This zone has the advantages of 

 a beautiful climate, a magnificent deep alluvial soil, good drain- 

 age, and facility of access. Splendid forests of most valuable 

 timber alternate with pastures of the richest quality. But the 

 interior, and by far the larger part, of the Gran Chaco is totally 

 different. The usual utter absence of fresh water, and the poor- 

 ness of the soil and of the pastures, make the country unfit for 

 the agriculturist or the stock-raiser, while timber is comparatively 

 scarce. Mr. Kerr thinks that the Holy wood and the Cascarandd, 

 as limbers, and the Uvira as a textile plant, will probably be 

 found almost the only productions of value in the interior. 



The " British Journal Photographic Almanac and Photo- 

 grapher's Daily Companion " for this year, edited by J. Traill 

 Taylor, seems to have increased in bulk, and is as interesting 

 as ever. The articles on 'the many and various subjects which 

 are dealt with by the contributors are well worth perusal. The 

 tables and the general information given in the volume are all that 

 a photographer requires. The frontispiece, which is a likeness 

 of William II., Emperor of Germany, is from a negative by 

 Messrs. Russell and Sons, and is produced here on bromide 

 paper, as an example of an average print. 



Messrs, George Philip and Son have issued a valuable 

 little book on " Technical Education in the Counties," by George 

 J. Michell and Ernest Ileber Smith. It is based on a series of 

 articles which appeared last year in the County Council Times. 

 The authors have had a large experience in teaching the classes 



NO. II 63. VOL. 45] 



who will be specially affected by the new instruction provided 

 by the Technicallnstruction Act. After a general chapter on 

 national education, they deal with special agricultural require 

 ments, night science agricultural schools, the cost of secondary 

 and night science and agricultural schools, higher agricultural 

 schools, and agricultural colleges and universities. Among 

 other subjects discussed are the requirements of mining districts, 

 manufacturingsand engineering requirements, .and the educational 

 needs of girls. 



The Cambridge University Press has issued a " Catalogue of 

 the Type Fossils in the Woodwardian Museum, Cambridge," by 

 Henry Woods, of St. John's College, Prof. T. McKenny 

 Hughes contributes a preface. 



Messrs. J. B. Balliere et Fils, Paris, have issued a 

 French translation of ten well-known essays by Prof. Huxley. 

 The volume is entitled " Les Problemes de la Geologic et de la 

 Paleontologie." 



The United States National Museum has published a paper, 

 by Prof. E. D. Cope, on the characters of some Palaeozoic 

 fishes. 



Charles Lunn's "Philosophy of the Voice" has been 

 translated into German by Herr Ludwig J. Triig. A special 

 value is given to this translation by various additions which 

 have been made by Mr. Lunn himself. 



Two new compounds of carbon, chlorine, and bromine are 

 described by M. Besson in the current number of the Comptes 

 rendus. There are three possible chlorobromides of carbon — 

 CClgBr, CCIaBrj, and CClBrj. The first of these compounds, 

 CClgBr, was obtained some time ago by Messrs. Friedel and 

 Silva, by heating bromine and chloroform together in sealed 

 tubes to 170" C. M. Besson now shows that this reaction, when 

 carried further at higher temperatures, yields all three chloro- 

 bromides, which may readily be separated by fractional distilla- 

 tion. The mixture of bromine and chloroform, in the propor- 

 tion of two atoms of the former to each molecule of the latter, 

 is best heated in a sealed tube first for two hours at 225". The 

 end of the tube is then softened in the blow-pipe flame, in order 

 to permit of the escape of the hydrobromic acid which is evolved 

 during the first stage of the reaction. The tube is then closed, 

 and again heated, this time to 250°, after which it is reopened, 

 and the pressure of gas, which is now mainly hydrochloric acid, 

 released. The tube is finally closed, and heated to 275°, at 

 which temperature the reaction is complete. By proceeding in 

 this manner, the risk of the tube being fractured by the enor- 

 mous pressure of the evolved hydrobromic and hydrochloric acids 

 is minimized. The explanation of the formation of all three 

 chlorobromides is probably as follows. The bromine first reacts 

 with the chloroform with production of the direct substitution 

 products, CCljBr and CClgBrj, according to the equations 

 CHCI3 -f- Brj = CCIsBr -I- HBr, 

 CHCI3 -h Bra = CCljBra -1- HCl. 

 Subsequently, at a higher temperature, the hydrobromic acid 

 reacts upon the compound CClaBrj, producing CClBrj and 

 hydrochloric acid, 



CClaBro -f HBr = CClBrj -+- HCl. 

 It would doubtless be more profitable to complete the whole 

 reaction at once by heating to 250" if glass tubes were capable 

 of withstanding the pressure, but M. Besson finds that they 

 invariably burst if this is attempted. Upon fractionally distilling 

 the product of the reaction, three fractions are obtained. The 

 first, boiling at 103-105°, consists of CCIjBr ; the second, which 

 distils constantly at 135° and usually solidifies in the receiver, 

 consists of CCL^Brj ; the third fraction, consisting of CClBrg, 

 boils at 160°, and rapidly solidifies as it condenses. The first 



