254 



NATURE 



[January ii, 1894 



tinuous current is passed from one of these electrodes to the 

 other, through the liquid contained in the vessel, the strength of 

 the current being controlled by an internal resistance. A vertical 

 spindle at the centre of the trough carries a revolving arm pro- 

 vided with conducting plates or electrodes at its extremities. 

 These plates are insulated from one another, and are connected 

 to two ring contacts carried by the central spindle. Two brushes 

 bear on these rings, and convey the alternating current. By 

 suitably altering the connections and electrodes, it is possible in 

 the same manner to obtain multiphase currents. The author 

 finds that the currents obtained are practically sinusoidal, and 

 lie suggests that they will be of considerable physiological use. 



At a recent meeting of the Societe Francaise de Physique, 

 M. Hurmuzescu showed some experiments on electrical con- 

 vection in air. He finds that if you cause dissymmetry between 

 the two discharging knobs of a Wimshurst electrical machine, 

 by fixing a point to one of them, then, on placing a sensitive 

 gold-leaf electroscope at a distance of about two metres, when 

 the machine is worked, the discharging knobs being separated, 

 the electroscope becomes charged. The electroscope becomes 

 more highly charged when it is fitted with a point than when it 

 has only a varnished ball at the end of its electrode. That the 

 charge is not due to induction, but to convection through the 

 air, is shown by the fact that the interposition of a metallic screen 

 does not interfere with the effect, while if the electroscope is 

 covered over by an insulating shade no electrification is ob- 

 servable. In addition, it is found that the charge on the 

 electroscope is of the same sign as that of the terminal of the 

 machine on which the point is fixed. The most marked and 

 rapid results are obtained when the point on the machine is 

 negatively electrified, while no effects are observed if the point 

 is turned towards the plates of the machine. 



An account of Victor Schumann's successes in photograph- 

 ing rays of very short wave-lengths is given in No. 50, of the 

 Natunoissenschaftliche Rundschmi. These successes are 

 entirely due to the elimination of absorption by the material 

 used in the prisms and lenses and, what is especially note- 

 worthy, of the layers of air intervening between the luminous 

 source and the plate used for photographing the spectrum. 

 This elimination has resulted in the exhaustive exploration of 

 the hitherto doubtful ultra-violet region between 231 '4 and 

 185 '2 fi-fx., and the annexation of the region down to 100 yii^ 

 to the known spectrum. For this it was necessary to get rid 

 of the absorption due to the film of gelatine in which the 

 sensitive silver salt was embedded, and this was accomplished 

 by the substitution of a pure silver bromide plate. The camera, 

 the spectroscopic apparatus, and the spark tube were all con- 

 nected together and exhausted. The very first exposure on 

 the hydrogen spectrum showed that the known radiations of 

 that gas only represent a portion of '-its total radiance. The 

 newly-traced portion turned out to be extremely rich in lines, 

 with a maximum at about 162 ju/i, and consisted of fifteen 

 groups of lines disposed pretty evenly, containing altogether 

 about 600 lines, with intensities decreasing from the maximum 

 in both directions, rapidly at first, and then very gradually. 

 The wave-lengths of these lines are as yet undetermined. Pro- 

 visionally, that of the smallest wave-length recorded is 

 estimated at 100 ju/t. The spectra of aluminium, cadmium, 

 cobalt, and other metals end at about 170 [x.11.. A layer of 

 normal air i mm. in thickness appears capable of absorbing all 

 radiation of smaller wave-length than that. Dry gelatine 

 absorbs eagerly all waves beyond 217 ^/t,. Quartz is not 

 suitable for prisms and lenses, and white fluor-spar is, so far, the 

 only material that answers all requirements. The accurate 

 determination of the new wave-lengths, the further investigation 

 of the absorption due to air, and the further extension of the 



NO. 1263, VOL. 49] 



ultra-violet region, are the problems which Herr Schumann is 

 now working at. 



In a note published in Nature on July 20, attention was 

 drawn to the manner in which the virulence of the typhoid 

 bacillus may be increased by the products of other organisms 

 being inoculated along with it into animals. In an elaborate 

 paper, recently published in the Aniiali deW Istitiito d'lgiene di 

 Roma^ vol. iii. 1893, p. 117, Roncali shows how the virulence 

 of the tetanus bacillus may be intensified by similar means. 

 Thus an animal inoculated with this organism usually 

 succumbs in three days ; if, however, the soluble products of 

 this bacillus be accompanied with those of some other organism, 

 death ensues with tetanic symptoms in from 12-26 hours. It 

 was also found that if by some means or other the power of 

 resistance inherent in the animal was first diminished, the 

 action of the tetanus toxine was greatly accelerated. This 

 condition of diminished resistance was obtained by either first 

 inoculating some other organism, or by introducing putrid 

 infusions of meat or vegetables in themselves proved to be 

 perfectly harmless to the animal in question. To further 

 illustrate this point, symptoms of chronic tetanus were induced 

 in animals by the inoculation of the soluble products of the 

 tetanus bacillus obtained after from 3-4 days' growth. After 

 from 8-10 days, if pathogenic or non-pathogenic organisms were 

 introduced, the animals died in from 16-18 hours, whilst if they 

 were not subsequently interfered with, they usually recovered in 

 from 20-35 days. In the course of these investigations the inter- 

 esting discovery was made that the bacillus of rabbit septicasmia, 

 which is usually non-pathogenic to mice, may be rendered fatal 

 to the latter by cultivation on agar-agar containing the soluble 

 products of the tetanus bacillus. These experiments indicate 

 how harmless saprophytes, such as the b. prodigiosns, may 

 under given conditions become the servants of disease organisms, 

 either by diminishing an animal's power of resistance, and so 

 preparing the way for the entrance and work of pathogenic 

 bacteria, or by hastening the lethal action of the latter by 

 subsequent intrusion into the system of the infected animal. 



We have received three fascicules of the forthcoming volumes 

 of the Met/ioirs (Zapiski) of the Russian Geographical Society. 

 One of them contains D. Pokotilov's elaborate paper, " U-tai,^ 

 its Past and Present," given to the description of the holy 

 mountain of the Buddhists and its numerous monasteries. M. 

 Pokotilov has followed the same route as Dr. Jos. Edkins 

 ("Religion in China"'); and also describes his journey from 

 Pekin to the U-tai Mountain ; but he also gives a detailed 

 description of the Buddhist sanctuary, and the history of the 

 development of Buddhist monasteries at this spot. The 

 learned Russian scholar has utilised, moreover, the Chinese 

 works devoted to the same subject. Taken in connection with 

 Prof. Pozdneev's large work, " Sketches of the Life of Buddhist 

 Monasteries and Buddhist Clergy," lately published in the 

 Memoirs of the same Society (Ethnography, vol. xvi., 1887), 

 M. Pokotilov's paper is a very valuable addition to the literature 

 of the subject. Another fascicule of the Zapiski (Geography, 

 vol. XV. No. 3) contains F. Schwartz's report on his astrono- 

 mical, magnetical, and barometrical observations in Bokhara, 

 Darvaz, Karateghin, and Russian Turkestan, made in 1886. A 

 third fascicule (Statistics, vol. vii. No. 2) contains a detailed 

 description of the Eritrean colony of Italy, by M. A. Troy- 

 ansky. 



The Physical Society of London has just issued the third 

 part of vol. xii. of its Proceedings. 



The first part is published of the new Flore de France (in 

 eluding Corsica and Alsace-Lorraine), by MM. G. Rouy and 

 J. Foucaud. 



