June 7, 1894] 



NA TURE 



tion of the laboratory. The fact that eighteen different 

 colleges and universities now contribute annually to the support 

 of tables in the laboratory is very encouraging, as showing a 

 wide spread interest in the laboratory as the summer working- 

 place of bolti instructors and students interested in biology. It 

 is the aid thus obtained from colleges and universities which, 

 for the first time since its establishment, has rendered the 

 laboratory self-supporting during the past season. The number 

 of students and investigators occupying work-tables last summer 

 was one hundred and eleven, this being the extreme limit of 

 accommodation. There is every reason to believe that the 

 number of applicants for places during the coming summer will 

 considerably exceed the present capacity of the laboratory, and, 

 unless the present building is enlarged, it will be impossible to ac- 

 commodate them. The trustees hope that provision will be made 

 for the increasing number of students. Further, they have to 

 consider the question of the extension of the field of usefulness 

 by the introduction of departments of biology not yet repre- 

 sented, and the development of those recently introduced into 

 the institution. Such an extension implies an increase of 

 working room, as well as an increase in the laboratory equip- 

 ment. For the first time, the laboratory numbered last summer 

 among its workers investigators in comparative pathology, and 

 it is thought that, in the near future, this branch of biology 

 should be included among the lines of investigation to be carried 

 on in the laboratory, as are zoology, botany, and physiology at 

 the present time. 



A RECENT number of Science contains a short article on i 

 the employment of disease-causing microbes for the destruction 

 of field mice and similar vermin, in which attention is called to 

 a paper on this subject recently presented to the French 

 Academy by M. Jean Danysz. The microbe employed in pro- 

 ducing artificially a destructive epidemic amongst these trouble- 

 some vermin, is stated by the author to be very similar to the 

 bacillus of duck cholera, but is not identical, for it is not patho- I 

 genie either to these birds or other fowls. Both Loftier and ' 

 Lasar have discovered similar microbial enemies to field mice 

 which have been used with marked success for the suppression 

 of plagues of these animals, but so far in the United Stales they 

 have been content to use poisoned grain or carbon bisulphide 

 for this purpose ; but Mr. Gerald M'Carthy's interesting little 

 article will no doubt attract attention to this more novel method 

 of dealing with such vermin. Another article in this number 

 is on the self-purification of rivers, a subject upon which so 

 much difl'erence of opinion exists, that it invariably aflbrds 

 ample material for discussion. The aeration of the water of 

 rivers in falling over dams and natural obstruct! jns, has been 

 regarded by some as exerting an important influence in purifica- 

 tion, but according to the experiment made by Trof. Leeds 

 upon the water above and below Niagara Falls, where natural 

 aeration is carried on to the utmost extent possible, no chemical 

 purification is effected during the process. The bacterial 

 aspect of the subject is also discussed, and the writer closes his 

 article with the observation that "a river which receives 

 sewage should be considered unfit to serve as a public water 

 supply." Fortunately in this country we are alive to this 

 objection, but many of the largest cities in America invariably 

 use sewage polluted river-water unpurified, resulting in severe 

 epidemics of typhoid fever. 



A Port Blair correspondent of the Allahabad Pioneer 

 announces the discovery of the remains of an elephant on South 

 Sentinel, an islet about twenty miles from any other land. The 

 remains were buried about nine inches below the surface, and 

 since the yearly deposit of soil on the island must be very small, 

 it is supposed that they are of very considerable age. It is, 

 moreover, interesting to learn that the volcano on Barren Island 

 is apparently entering upon a period of renewed activity. 

 NO. 1284, VOL. 50] 



The Washington letter in the last number of the Bulletin of 

 the American Geogr.iphical Society announces that the recent 

 study of the observations on mountain summits in the neigh- 

 bourhood of Mount St. Elias, shows that Mount Logan is the 

 loftiest peak in North America with a height of 19,500 feel, 

 thus being 1 200 feet higher than Orizaba, and 1500 feet higher 

 than Mount St. Elias itself. 



The June number of the Geographical yournal completes the 

 third volume of the new form of the monthly publication of the 

 Royal Geographical .Society. It contains an exceptional range 

 of geographical news, including the text of Mr. Littledale's 

 paper on his recent journey across Central .-Xsia, with a series 

 of original maps and illustrations. Mr. Dolby Tyler cDntributes 

 an account of his journey up the river Napo, perhaps the least 

 known of all the tributaries of the Amazon. There is an ex- 

 cellent account of the primitive " Indians " of the region. Mr. 

 Ravenstein, in a lightly written article on recent African books, 

 incidentally calls attention to the immense flood of literature on 

 that continent now appearing, his list including twenty-one 

 works, all published within the last few months. Mr. H. Yule 

 Oldham has a most readable account of the Manchester ship- 

 canal, showing its peculiar geographical importance, and Mr. 

 A. Montefiore gives a note on the geography of Franz-Josef 

 Land. 



The Scottish Geographical Magazine for June contains the 

 first part of an extremely valuable paper by Prof. Otto Petters- 

 son, of Stockholm, on Swedish hydrographical work on the 

 Bailie and North Seas. He uses hydrographical not in the 

 ordinary English sense of a mere survey by soundings, but with 

 the wider meaning of a physical and chemical examination of 

 the water. This first part, indeed, is mainly chemical, detailing 

 the processes employed for analysing the dissolved gases and 

 determining the salinity and density of seawater. The author's 

 opinion that the use of hydrometers in marine research is nearly 

 past, and that only determinations of density by weighing with 

 apparatus similar to Sprengel's pyknometer can be held as suffi- 

 ciently accurate, is not corroborated by the experience of most 

 British oceanographers in whose hands the Ciallenger-typs 

 hydrometer has given most excellent results. The Edinburgh 

 magazine sustains by this article the high reputation it has long 

 held as the first English authority on oceanography, and it is to 

 be congratulated on securing the first publication in any lan- 

 guage usually read by scientific men outside Scandinavia of so 

 original and able a treatise. 



The current number of lyieJcmann's Anitalen contains 

 a paper on the similarity between the after-glow of a 

 Geissler tube and the first glow of solid bodies, by Carl Kirn. 

 Hcrr H. F. Weber has shown that the first light which be- 

 comes visible when a solid body is healed, is not, as was 

 supposed by Diaper, dark red but grey, which shows itself 

 spectroscopically as a band in the yellow-green. The researches 

 of Stenger and Ebert on ihe limits of the visible light have shown 

 that the phenomenon was caused by the different sensitiveness 

 of the eye to the diflerent colours, this sensitiveness being a 

 maximum for that part of the spectrum where the baud of grey 

 light is first seen. The Geissler tube employed by the author 

 exhibited, after an electric discharge had been passed through 

 it, all the phenomena observed by Riess and Morren ; the 

 yellowish-white after-glow of the bultjs being visible for more 

 than half a minute in a completely dark room. Tiie light 

 being observed with a spectroscope, it was found that, while 

 the discharge was actually p.issing, the tube gave a line spec- 

 trum, the brightest lines coinciding with those of niirogen and 

 carbonic oxide. The feeble spectrum of the after-glow, how- 

 ever, is continuous, and at first occupies the entire spac; covered 

 by the previously nientioaed line spectrum, but it shrinks fairly 



