Sectember 2o, 1894] 



ATA TURE 



'^o;. 



asy acid, gives a solution whose resistance increases with rise of 

 temperature. 



In a paper contributed to the Archives N^irlaiiJaiits, >r.P. 



■-■min gives an account of the observations he has made on the 

 Kerr phenomenon on the reflection from surfaces of iron, cobalt, I 

 and nickel in a magnetic field. The author has continued the 

 experiments commenced by M. Sissingh, using a slightly modified 

 form of apparatus. He finds that the difference between the 

 observed and calculated jihases (obtained from Lorentz's 

 formulDe) is practically constant for radiation of all wavelengths, 

 and is equal to 80^ in the case of iron. Similar results were 

 obtained with nickel and cobalt. In the case of these two 

 metals the author, after attempting to obtain suitable mirrors by 

 the deposit of the melal on polished iron, or by electrolysis, was 

 obliged to have plane faces cut on blocks of the pure metal, 

 which when polished formed good mirrors. 



The specific heat of gases at constant pressure has been 

 invesligated by Dr. Silvio Lussana, by means of a new and 

 ingenious apparatus. The contrivance, as described in the 

 Nuovo Ciintnlo, is intended to overco^ne the difficulty of pro- 

 viding a sufficient quantity of gas to experiment upon. With 

 the resources of an ordinary physical laboratory it is ditTicult to 

 obtain a pure gas in sufficient quantity to mike an impression 

 upon the calorimeter, so Dr. Lussana decided to use the same 

 quantity over and over again. Two substantial iron tubes were 

 placed vertically, and communicaied at the bottom by means of 

 an india-rubber tube strengthened with five layers of canvas. 

 They were partly filled with mercury, and by elevating or lower- 

 ing one of them the mercury could be made to completely fill the 

 one or the other. When one tube was full of merciuy, the other 

 was filled with the gas to be investigated, and the amount of gas 

 which filled the tube could be driven out and through the 

 calitimeler by lowering the tube. The gas was then made to 

 pass through an india-rubber tube leading 10 a brass worm 

 immersed in a heating bath, and another immersed in water, 

 «liich constituted the calorimeter. It then passed througli a 



nail subsidiary worm, to test whether it had lost all the heat 

 [uired, and finally entered the other iron tube which wa-i being 



iipticd of mercury. By means of a short circuit provided with 

 a valve, the gas and the mercury in the two iron tubes could 

 be exchangeil, and the same process repealed. The water 

 equivalent of the calorimeter was dilermined experimentally by 

 ■i^nding a measured quantity of hot water through it. To ensure 



jnstancy of pressure, the level of the mercury was always 

 adjusted to the same fiducial mark on a short length of glass 

 tubing introduced in the in lia-rubber tube. The gas was intro- 

 duced by a Natlerer compression pump. Seeing that pressures 

 were employed up to forty almosphere>, special care had to be 

 bestowed upon stop-cocks and junctions, some of which were 

 constructed in a novel manner. The results of the measure- 

 ments, which promise to be of great interest, will shortly bj 

 published. 



Thk May number of the Trans ictions of the North of Eii^- 

 ■ltd Institute of Technical Brewing, a copy of which has been 

 sent to us, contains an interesting an 1 very useful paper by 

 Mr. Fellowes, on '■ Some of the microorganisms causing the 

 diseases of beer. " M:!ntion is made of the important services 

 rendered by Pasteur, Hansen, Van Laer, Lindner and others to 

 this subject, and we are introduced to quite a number of 

 raicrobic foes with all of which the brewer has to wage war. 

 The cause of viscosity in beers has recently been elaborately 

 stodied by Van Laer, who has isolated certain microorganisms 

 which he has classed together under the name of Bacillus 

 viscosui. When these organisms are introduced into sterilised 

 wort along with pare yeast, the liquid is reniered mire or less 

 ropy, the decree of viscosity depending upon the proportion in 



NO. 1299, VOL. 50] 



which the disease organism is introduced. Curiously, however, 

 although the Bacillus viscosus behaves in this characteristic 

 manner in the case of Belgian beers, s > far, similar results have 

 not been obt.ainci with it when subjected to the English system 

 of fermentation. Mr. Fellowes his himself isolated various 

 organisms present in samples of viscid beer, bat has not been 

 able to obtain with such pure cultures or individual varieties a 

 viscosity equal to that of the sample from which they were 

 originally derived. Hesu^'ests thi'. the cause of this failure 

 may be sought in the probable modifications induced in the 

 physiological character o.'' the micro-orginisms daring the 

 process of isolation by mean; of gelatine cultures. In support 

 of this suppisition he refers to Prof. Percy Frankland's investi- 

 gations on the fermentation of calcium citrate by means of a 

 particular bacillus, which although in the habit of fermenting 

 this .substance, for years past abs jlutely refused to do so when 

 introduced into calcium citrate solutions direct from gelatine 

 cultures. Mr. Fellowes is of opinion that the viscosity in 

 English beers may be due to the associated action of various 

 micro-organisms present, their activity depending not only on 

 the particular varieties, but also on the relative numerical 

 strength in which they are present. It is obvious that to 

 obtain such particular conditions artificially is by no means an 

 easy task, but there can be no doubt that a wide field for 

 research on the question of symbiotic fermentation, or the 

 associated life of micro-organisms, remiiasyet to be explored. 



The Berichte der Deutschen B.^'.anischen Gesellschaft, vol. xii. 

 part 5, contains a paper, by J. E. Humphrey, on nucleoli ani 

 centrosomcs. The author favours the theory thit the nucleolus 

 is not a definite organ of the nucleus, but regards ir, with Stras- 

 burger and Gui^nard, as a reserve material of the nucleus. In 

 this connection he examined the nuclei of the sporangia of 

 Psilotum triijuetrum, in which Karsten considers that the cen- 

 trosomes of the dividing nuclei arise from the nucleoli, and 

 after division are re-included in the daughter nuclei. IIis 

 observations, however, lead him to the conclusion that .the 

 nucleoli and centrosomes are completely distinct from one 

 another, and that the latter are altogether extra-nuclear. 

 Another interesting result, which he obtained in the coarse of 

 his observations, is that the body, which is often found in con- 

 nection with the nuclei of the pollen-sac, and which his been 

 called the " paranucleolus," is probably not a natural structure, 

 bat is formed daring the process of fixing the material in which 

 it is found, as it was seen regularly on that side of the nuclei 

 which was the last to be reached by the fixing fluid. 



N.VTURAi.ISTS may sometimes have wondered that a region 

 so classical in the annals of marine biology as the neighbour- 

 hood of St. Vaast-Ia-Hougue w.is no; earlier made the site of 

 one of those marine laboratories which our neighbours across 

 the Channel conduct with such efficiency and economy. For 

 some years past, however, the Museum of Natural History of 

 Paris has been engaged in altering and refitting the extensive 

 buildings of an ancient lazaret on the island of Tatihou to this 

 end, and at the first September meeting of the Academy of 

 Sciences M. Edinond Perrier was able to report the practical 

 completion of the laboratory. A circulation of sea-water has 

 been fitted up throughout the laboratories and tank-rooms, and 

 marine animals of all kinds live perfectly within the aquaria. 

 M. Malard-Damcril, the naturalist in charge, and his stall 

 reside permanently upon the spot, and there is full accommo- 

 dation for eighteen additional naturalists. The work of the 

 new laboratory is not, however, to be limited to the promotion 

 of pure scientific research, but, if the hopes of its founders are 

 reahsed, will also include operations on a practical scale in 

 marine pisciculture. 



