518 SUMMARY OF CUKRENT RESEARCHES RELATING TO 



with the ultra-rays of potassium iodide. 3, The wave-length of each 

 series is stated in the following table. That of the stronger series is in- 

 dicated by a 1; that of the weaker by A 2 , the " medium " being a . The 

 table also jnves the molecular weight M of the substances. 



Utra-rays from a, A„ A.„ M 



Rocksalt 

 Sylvine 



Potassium bromide 

 Potassium iodide 



It is to be noticed that the medium wave-lengths increase with the 

 molecular weights — more slowly than the molecular weights, but more 

 rapidly than their square roots. (The " medium " is got by dividing the 

 half-wave length into the distance between two adjacent maxima or 

 minima.) 4. The refractive index of water is about A = 82*3 /j., and 

 is of the same order of magnitude as in the visible spectrum. 5. By 

 examination of the ultra-rays of potassium bromide our knowledge of 

 the spectrum has been increased by about half an octave. The spec- 

 trum now comprises ten complete octaves, of which two are in the 

 ultra-violet, one in the visible region, and seven in the ultra-red. 



Phenomena of Light-polarization in Solid and Pseudo-liquid 

 Organized Matter.* — P. de Heen points out that, according to present 

 ideas, matter is constituted by ionic fibres traversed by magnetic currents 

 or by currents of ether, and all the phenomena of polarization are the 

 result of the orientation of these magnetic fibres or of the predominant 

 action of certain orientations (polarization by reflection or by refraction). 

 It is interesting to enquire what difference exists between a network of 

 fibres oriented to form a magnetic field and a network of fibres active as 

 regards polarization of the light. The only difference lies in the circum- 

 stance that, to obtain an active substance, all the atomic bobbins must 

 be wound in the same sense. The author explains fully his reasons for 

 arriving at this conclusion. 



(.6) Miscellaneous. 



Quekett Microscopical Club. — The 465th Ordinary Meeting was 

 held on April 26, at 20 Hanover Square, W., the President, Professor 

 E. A. Minchin, M.A., F.Z.S., in the Chair. Mr. A. E. Hilton read a 

 paper on " The Life-phases of Mycetozoa." The author gave a detailed 

 description of the life-cycle of this group, which includes less than 300 

 species, and said that this small group offered exceptional opportunity 

 for studying life-phenomena, as the processes were less obscured than in 

 many other organisms. Mr. Hilton exhibited active living swarm- 

 spores of Mycetozoa x 500. Mr. James Burton read a note on " Two 

 Instances of Breaking of the Meres." The term may be defined as that 



* Bull. Classe Sci., Acad. Roy. Belg., 1910, pp. 23-30 (5 figs.). 



