398 



KNOWLEDGE & SCIENTIFIC NEWS. 



[April, 1906. 



a plume-like rosy lii^ht, the other a plume-like violet 

 light. These discharg-es also revolved around the pole 

 near the centre of the disc instead of on the circum- 

 ference, as in the case of the cathode disc. On account 

 of the number of individual discharges on the anode il 

 was difficult to follow their motions in a revolving 

 mirror, or by the eye, or to photograph them. It was 

 ceitaiii, however, that they rcv(jivc-d about the pole. 



Dr. Trowbridge draws the following inferences from 

 the experiments : — 



The unipolar rotation which 1 have described leads 



Fie. 



my mind to connect the phenomenon of coronal 

 streamers seen at the poles of the sun in an eclipse 

 with the effect of a magnetic field on possible electrical 

 discharges between the equatorial regions of the sun 

 and the poles of the sun. If we suppose that a differ- 

 ence of electrical potential can arise between the swiftly 

 moving strata of gases or from the eruptions which 

 take place mainly along the equatorial belt and the polar 

 regions, the supposed magnetic poles of the sun would 

 undoubtedlv tend to cause the resulting electric dis- 

 charges to revolve about the pole. On account of the 



Fig, 3, 



vast circumferential area about the poles a number of 

 discharges could occur at different points around the 

 pole and each discharge would revolve under the effect 

 of the pole. In observing the effect of a strong mag- 

 netic pole on plate terminals in wide tubes of rarefied 

 air, at comparatively high pressure of air under condi- 

 tions of high electromotive force and great current 

 density, one can observe phenomena of rotation which 

 cannot be photographed yet which present to the eye 

 a strong analogy to the appearance of coronal 

 streamers. 



I arranged a number of collections of bristles on a 

 disc which was then set in rapid rotation. l*"ig. 2 is a 

 photograph of the appearance of such revolving 

 streamers, which represent fairlv well what may be 

 seen at the terminal of a discharge tube in a magnetic 

 field. 



There is, however, another magnetic phenomenon 

 uiiich may have a bearing upon the coronal streamers 

 at the poles of the sun. When the lines of magnetic 

 force are at right angles, or transverse to the direction 

 of the electric discharge, at comparatively high pres- 

 sures, one to two centimetres, with currents from 5 

 to 20 centimetres, 3,000 to 8,000 volts in wide tube 

 streamers radiate from the position of the magnetic 

 pole. 



Fig. 3 is a photograph of such streamers or strati- 

 lications. " It will be noted," says Dr. Trowbridge, 

 "That these stria? make their appearance at a much 

 higher pressure than that of the usual striae in rarefied 

 gases." Similarly, electric discharges around or to- 

 wards the poles of the sun, transverse to the lines of 

 magnetic poles of the sun. could be separated into 

 ".treamers. 



Mice a.nd Pnexjmonia.. 



Oh late years it has been confidently asserted by the 

 bacteriologists that the domestic cat is the harbourer 

 and the propagator of the germ influenza. .\n equally 

 serious accusation is being made against the domestic 

 mouse, which is said to be a probable disseminator of 

 pneumonia. The bacillus which usually is held to pro- 

 duce pneumonia is, in one form, that of the pneumo- 

 coccus bacillus, very generally with us; and it has been 

 sometimes assumed that the reason why it is a more 

 successful enemy of the human race in the winter 

 months — December, January, February, and March — is 

 the smaller resistance which we offer to it in this season 

 of reduced vitality. Tliat is a fairly sound hypothesis. 

 Sir Lauder Brunton has shown, for example, that fowls, 

 which are normally immune from pneumonia, can be 

 made susceptible if they are kept standing long enough 

 in cold water. But Dr. E. Palier, in the Xew York 

 I\ledical Record, has another suggestion to offer. The 

 common bacillus ol pneumonia, for which he proposes 

 the name of " diplo-lanceo-bacilli-cocci," becomes viru- 

 lent only, he maintains, when it has attained a new 

 \ Itality by passing through the system of an animal 

 extremely susceptible to it. Such an animal is found in 

 the mouse, and especially in young mice, which are 

 very readily susceptible, and to which the disease 

 usually proves fatal. ITiese mice, which are especially 

 plentiful in the winter months, and are more noticeable 

 in the insides of houses, take up the pneumococcus of 

 human beings, absorb it, and restore it in augmented 

 numbers and more virulent form. In poorly ventilated 

 rooms the virulent " d.l.b.c", as Dr. Palier shortly 

 terms the characteristic bacillus emanating from in- 

 fected mice or from their decomposing- bodies, become 

 abundant. Dr. Palier claims for his theory that it 

 appears a plausible explanation of the duration of pneu- 

 monia. Virulent "d.l.b.c." do not lose their virulence 

 at once, but after the third or fourth generation. 

 \\'hen the virulent " d.l.b.c." enters the human bodv, 

 some seven or nine days elapse before they are reduced 

 to comparative harmlessness. It is possible that other 

 animals besides mice may act as temporary hosts. 



