70 



NATURE 



\Nov. i6, i8 



that of the atmosphere proved, however, dhectly the contrary, 

 and a series of measurements undertaken some years ago by 

 Prof. Mendeleeiif to verify those of Regnault, gave the same 

 results. Suspecting that there might be some cause of error 

 affecting in the same way both series of experiments, Prof. 

 Mendeleeff and M. Bogussky constructed special apparatus 

 eliminating all possible causes of errors and allowing the most 

 perfect accuracy of measurements. With these they made a new 

 series of researches, at pressures varying from 700 to 2,200 

 millimetres. These researches confirmed again the conclusions 

 of Regnault, showing only numerical differences in the values 

 obtained, and proving, for instance for the air, that its deviations 

 from Mariotte's law are even less than appeared before. But 

 the most important result of the researches is that the divergences 

 from Mariotte's law shown by the air being negative at pressures 

 above the mean atmosphere, as was observed by Regnault, 

 proved to be positive (decrease of volume slovvtr than the 

 increase of pressure) at pressures below it. We must then con- 

 clude that tlie air experiences a change of compressibiliiy at a 

 certaifi pressure about the mean of that of the atmosphere ; and 

 this conclusion is supported by the circumstance that such a 

 change was noticed also in the carbonic and sulphurous acid 

 gases, but at pressures far lower than is the case for air. Only 

 lor hydrogen the divergence is of the positive kind at all pres- 

 sures. Altogether we must conclude that the deviations from 

 Mariotte's law are far more complicated than has been suspected. 



At the same meeting Prof. Czehovicz demonstrated the influ- 

 ence exercised by various sources of electricity on certain spectra, 

 chlorine, oxide of carbon, &c. The inductive apparatus of 

 Ruhmkorf gives a spectrum differing from that produced by the 

 Holtz electric machine, not only by the number of rays, but also 

 by their position and aspects. Prof. Czehovicz proposes there- 

 fore lo make for comparative researches a selection of such rays 

 as maintain the same aspect and occupy the same position 

 wliatever source of electricity be used ; such lines will not be 

 numerous. 



At the same meeting Prof. Grewingck presented the drawing 

 of his geological map of the Baltic provinces, prepared for a 

 second edition. It embodies the results of all acquisitions made 

 in this department during the last fifteen years, and will soon be 

 published. 



The Warsaw Zoological Museum having received during 

 recent years valuable additions from America, Africa, and 

 Eastern Siberia, presented by Count Branicky, is now very rich 

 in the department of higher animals. It counts 514 species of 

 mammalians, 3,216 of birds, and 4.00 of reptiles aird ampliibians. 



The Natural Science Club at Cambridge held several success- 

 ful meetings during tlie two months' residence in the Long 

 Vacation. The following papers were read : — " Hteckel's 

 Gastrasa Theory," by Mr. Marshall (St. John's) ; " Fermenta- 

 tion," by Mr. Stodart (St. Peter's) ; " Some Salts of Chromium," 

 by Mr. Houghton (St. John's) ; " The Relation between the 

 Fore and Hind Limbs of Vertebrates," by Mr. Pliillips (Sl 

 John's); "Growth," by Mr. Buxton (Trinity); "Theories of 

 Heredity," by Mr. Sedgwick (Trinity); "Owen's Vertebrate 

 Theory of the EkuU," by Mr. Humphry (Trinity) ; many 

 of which were followed by interesting discussions and re- 

 maiks. 



A German paper describes a dreadful fight between two Polar 

 bears, male and female, in the Cologne Zoological Gardens. 

 After a fierce struggle the female became exhausted, and was 

 dragged by the male into the water basin in the den, and held 

 down till life was quite extinct. He then pulled her out and 

 dragged the body for a considerable time round the den. 



From a correspondence in the Times we learn that the sta 

 of Faraday, subscribed for years ago, and entrusted to Foley 

 execute, was left by that sculptor in the clay at his death. Sii 

 then, Mr. Burch, the principal pupil of Foley, has been entrus 

 with the founding and completion of the work. 



The second edition of Brehm's well-known " Thierleben '' 

 about to be published in 100 parts, with entirely revised t 

 and with almost entirely new illustrations taken from life. 



At the meeting of the Mathematical Society, on Novembe) 

 the changes were made which we intimated in vol. xiv. p. 58: 



Part 5 of the second series of the great .work, in quar 

 upon the butterflies of America, with coloured drawings a 

 descriptions, has just been published by Mr. Edwards, throu 

 Hurd and Houghton, New York, and sustains the reputatior 

 its predecessors by the artistic elegance an 1 superiority of 

 illustrations. These consist of five plates, executed by Ri 

 Peart in her best style, giving, for the most part, not only 

 different sexes and varieties of the adult insects, but likewise 

 eggs, larvae, and chryssalides, and the favourite plants uj 

 which they feed. No new species are represented, althoi 

 several of those included are of great rarity. 



The City Press states that some of the Livery Companies h 

 a scheme in embryo for combining to form a College of Te 

 nical Instruction in a building to be erected on the That 

 Embankment. 



The Board for superintending non-collegiate students j 

 notice that an examination in physical science for the award 

 an exhibition of 50/. a year, granted by the Worshipful Comp 

 of Cloth workers, an i tenable for three years by a non-collegi 

 student, will be held in the Censor's rooms, 31, Trumping 

 Street, Cambridge, commencing on Thursday morning, Dec< 

 ber 14, 1876, at 9 o'clock. Fuller information as to the subji 

 of examination and the conditions of tenure of the exhibii 

 may be obtained from the Censor, Rev. R. B. Somerset, C; 

 bridge. 



A Caucasian Society of Naturalists has been recently ope 

 at Tiflis. 



The publishing house of Trlibner in Strasburg are issu 

 translations of Macmillan's Science Primers, under the supe! 

 tendence of the Professors of the University. There h 

 already appeared Roscoe's Chemistry and Balfour Stews 

 Physics, the former by Prof. Rose, and the latter by Prof. \A 

 burg, Lockyer's Astrononay, by Prof. Winnecke, and Geik 

 Physical Geography, by Prof. 03:ar Schmidt, are in the press 



The Augsburger All^emeim Zeitung of November 5 g 

 some interesting details of the North-Butch canal, which ' 

 opened officially by the King of Holland on the ist inst., 1 

 which connects tlie city of Amsterdam directly with the Gere 

 Ocean. It appears that the canal is 25 kilometres in lenj 

 that at its broidest part it measures 120 metres across its surl 

 by 68 metres ^at its narrowest part. In the middle the de 

 averages 6 metres, but during the next two years the depth i 

 be made uniform all over the area of the canal, and to be 

 creased to 8 20 metres, so that even the largest vessels can ct 

 clo;e to the quays on both sides of the canal. Its name ii 

 be Ymuiden, viz., mouth of the Y ; at the spot where it reac 

 the sea two enormous moles or dykes have been construci 

 reaching 1,600 'metres into the sea, and forming aspacijus \ 

 of refuge for ships during stormy weather ; their extreme ends 

 no less than i, 200 metres apart. The total cost of the canal, wl: 

 was borne by the Dutch Government as well as by the cit} 

 Amsterdam, amounted to more than twenty- six millions of flor 

 and it is expected that about seventeen millions more will 

 wanted for the construction of quays, warehouses, &c. ; yet 



