254 



NA TURE 



[July 15, 1897 



was accompanied " cum effigie Tychonis Brahei et exempio 

 ipsius manus." We may mention that only a small number has 

 been printed, and those wishing to acquire copies can do so 

 from the following address : — F. R. Friis, Copenhague, Cart 

 Adelersgade 7. 



The report on the operations of the Department of Land 

 Records and Agriculture, Madras Presidency, for the official 

 year 1895-96, has just reached us, and is full of interest. The 

 department, during the period under survey, appears to have 

 been most active in the performance of its duties, and good 

 work was carried on, or attempted under, in many instances, 

 great disadvantages. The unfavourable character of the 

 weather caused a failure in many of the planting experiments. 

 Courses of lectures were delivered on the subjects of agricultural 

 chemistry and veterinary science, and experiments were made 

 with various kinds of ploughs in Kurnool district. Inquiries 

 were made "as to whether any animal or vegetable parasites 

 have been anywhere observed, or can be found feeding upon 

 the prickly- pear in such a manner as to warrant a hope that it 

 might be used as an agency for destroying the said plant," and 

 the opinion arrived at, from the reports received, was that there 

 are no parasites known in the Presidency which can be depended 

 upon to destroy prickly-pear growth. 



The alleged reflexion of kathodic and Rontgen rays have 

 been made the subject of two independent but closely-allied 

 investigations by Prof. A. Battelli {Ntiovo Cimento, v. 4) and 

 M, P. Villard {Bull. Socicte Fratifaise de Physique, 95). Prof. 

 Battelli's conclusions are as follows : (i) It cannot be asserted 

 that kathodic rays are reflected according to the regular law ; 

 (2) rays coming from thfe speculum of a focus-tube have the 

 same properties as direct kathodic rays ; (3) the same properties 

 are possessed by rays coming from the anterior face of a very 

 thin lamina, on whose posterior face kathodic rays impinge ; 

 (4) a pencil of such rays seems to be constituted of diff"erent kinds 

 of rays which, when they fall on a thin body, appear to traverse 

 it in somewhat the same manner that they would traverse a 

 filter which allowed some rays to pass through more freely than 

 others. M. Villard finds that kathodic rays that have fallen on 

 a thin metallic lamina, emerge in the form of a diff"used pencil, 

 whose general direction is normal to the lamina, but the phe- 

 nomenon appears to be a kind of refraction. Reflexion is more 

 easily obtained, and the phenomenon can be photographed ; 

 the reflected rays possess all the properties of kathodic rays, and 

 are strongly deflected by the repulsive action. of the kathode. 

 Experiments show that this reflexion, though evidently anom- 

 alous, is perfectly definite. 



Dr. Italo Bosi contributes to the Nuovo Cimento, 4, v. a 

 series of observations on the electric resistance of solutions of 

 salts in motion, which have an important bearing on Hittorff"'s 

 and Arrhenius' theories of electrolysis. Dr. Bosi finds that in 

 solutions where the effect of electrolysis is to produce greater 

 concentration at the positive pole, the resistance increases when 

 the liquid is moving in the opposite direction to the current, and 

 decreases when it is moving in the same direction ; but the in- 

 crease in the first case is greater than the decrease in the 

 second. Where the concentration is greater at the negative 

 pole the effect is reversed ; the increase of resistance, however, 

 still exceeds the decrease. Finally, when electrolysis produces 

 no difference of concentration at the two electrodes, the resist- 

 ance is unaffected by the motion of the liquid. These con- 

 clusions do not entirely accord with the hypotheses either of ! 

 Hittorff or of Arrhenius. An investigation somewhat allied to 

 the present had previously been made by Edlund, but this was 

 rather qualitative than quantitative in character, and, moreover, [ 

 the fluids used by Edlund (town water, alcohol and water, and ' 

 others) left some doubt as to the nature of the dissolved salts \ 

 pontained in them. t 



JJO. 1446, VOL. 56] 



The American Naturalist for June contains an account, by 

 Mr. G. C. Whipple, of the biologicallaboratory instituted by the 

 Boston Water Works for the examination of the purity of the 

 water supplied to that city. The object of the laboratory work 

 is to ascertain and keep a record of the condition of the water in 

 all parts of the supply at the same time. The microscopical 

 work consists chiefly in the quantitative determination of the 

 various microscopic organisms, except bacteria, in each sample of 

 water, by the Sedgwick-Rafter method. In addition to this, the 

 number of bacteria is determined in the water of all the 

 reservoirs, aqueducts, and service-pipes, and a careful watch is 

 kept for those of a pathogenous character. It is stated that the 

 work done in this and in other similar biological laboratories in 

 Massachusetts (there is a separate one for the city of Lynn) has 

 been of great value, both from a purely scientific and from a 

 sanitary point of view, and that by these investigations the supply 

 of inferior water has several times been prevented. 



In " Minnesota Botanical Studies " {Bulletin No. 9, Parts x. 

 and xi. ), published by the Geological and Natural History Survey 

 of Minnesota, are several papers of more than local interest. 

 Mr. J. M. Holzinger calls attention to some mosses found by 

 him at high altitudes. On Pike's Peak, Colorado, between 

 altitudesof 12,502 feet and the top of the peak (14,147 feet), he 

 collected thirty species of mosses which deserve attention. Mr. 

 R. N. Day contributes a paper on the relative value of various 

 forces operative in the production of the positions of dorsiventral 

 leaves. He concludes that light cannot induce epinasty or 

 hyponasty, and adds : " This is in direct support of the position 

 taken by Vines, and the results upon which it is based demon- 

 strate that the photo-epinasty of Detmer does not exist as such." 

 Mr. A. A. Heller gives a valuable description of the ferns and 

 flowering plants of the Hawaiian Islands ; and the phenomena 

 of symbiosis is the subject of a paper by Mr. Albert Schneider. 

 Mr. Conway MacMillan, State Botanist of Minnesota, discusses 

 his observations of the distribution of plants along the shores of 

 the Lake of the" Woods, the purpose of his paper being to point 

 out the dependence of plant formations over such an area as the 

 shores of the lake upon topographic and environmental con- 

 ditions. It is shown how each formation may be explained 

 briefly as connected with a certain melange of ■ outward con- 

 ditions, and an effort is made to analyse these conditions both 

 by themselves and as connected with the growth of vegetation. 



The first part of an " Essai sur les elements de la mecanique 

 des particules," by M. H. Majlert, has been received from MM. 

 Gauthier-Villars et Fils, Paris. The object of the work is to 

 bring forward some new geometrical views on problems of 

 hydrodynamics. In the present part, entitled " Statique parti- 

 culaire," the author deals with general principles referring to 

 matter and energy, atoms and molecules, states of aggregation 

 of simple bodies, chemical combinations, and co-related subjects. 

 He reserves for a second part, to be published under the sub- 

 title " Dynamique particulaire," the results of his special studies 

 on energy and its manifestations ; and we reserve our review of 

 the work until that part appears. 



The fourth number of Archives of Skiagraphy, edited by 

 Mr. Sydney Rowland, has just been published. Among the 

 subjects and objects illustrated upon the six collotype plates are 

 the dislocation of an elbow, fracture of radius and ulna, the 

 lobster, edible crab, hermit crab, and five of Dr. Macintyre's 

 Rontgen photographs of a frog's leg in movement. 



Several articles on subjects of scientific interest appear in 

 the July magazines. Mrs. Percy Frankland gives in Longman^ s 

 Magazine an outline of the rise and development of bacteriologj' 

 during the past sixty years ; and to Good Words she contributes 

 a sketch of the career of the great leader of bacteriological 



