538 



NATURE 



[June 24, 1920 



stretched and cool on bein|:* released. This explains 

 the initial effects. (&) The muscle, like other colloidal 

 jellies, takes some time to reach an equilibrium 

 lenj^th on being stressed; consequently, on stretchinj^ 

 it more work is done, and on releasing it less work is 

 obtained than is accounted for by the elastic potential 

 enersiv existing in it when it has reached its full 

 equilibrium length. The balance in either case appears 

 as an irreversible production of heat. This accounts 

 for the secondary effects. The phenomena appear to 

 be of physical as well as of physiological interest. — 

 Sir James Dobbie and J. J. Fox : The absorption of 

 light by elements in the state of vapour : Selenium 

 and tellurium. In a previous communication (Proc. 

 A, 19 19, vol. xcv., p. 484) it was shown that the absorp- 

 tion of light by sulphur vapour reaches a maxiinum 

 at a temperature of about 650° C, and that at this 

 temperature the vapour density corresponds with the 

 average molecular weight S,. Selenium and tellurium 

 behave much in the same way as sulphur, the absorp- 

 tion increasing up to a certain temperature, above 

 which it again diminishes. In the case of selenium 

 the maximum absorption occurs between 650° C. and 

 700° C, and vapour-density determinations show that 

 the average molecular weight at this point corresponds 

 to Se,. With tellurium the maximum absorption is 

 found to occur about 1200° C. The vapour of this 

 element consists of. diatomic molecules at 1800° C, 

 but nothing is known of its constitution at lower 

 temperatures. Its general similarity, however, to 

 sulphur and selenium as regards absorption of light 

 renders it highly probable that at 1200° C, and below 

 this temperature, the vapour is much more complex 

 than at 1800" C. The absorption spectra of selenium 

 and tellurium are marked by the presence of large 

 numbers, of sharp narrow bands, and that of tellurium 

 shows, Q. wide absorption band of which the centre is 

 approximately at A 3800. — Sir James Dobbie and J. J. 

 Fox : The absorption of light by elements in the state 

 of vapour : Mercury, cadmium, zinc, phosphorus, 

 arsenic, and antimony. These elements, unlike those 

 of the sulphur group, do not show channelled absorp- 

 tion spectra when the Nernst filament is used as the 

 source of light. Mercury, cadmium, and zinc, which 

 are monatomic, transmit practically the whole of the 

 light at all temperatures. Cadmium, however, shows 

 a few narrow absorption bands, of which one at 

 A 3261 is the most striking. In the cases of the 

 tetratomic elements, phosphorus, arsenic, and anti- 

 mony, general absorption occurs and increases regu- 

 larly with rise of temperature up to 1400° C. There is 

 no indication of a maximum followed by a diminu- 

 tion of absorption. The peculiar absorption pheno- 

 mena of the elements of the sulphur group are in all 

 probability due to the breaking-down of complex into 

 simpler molecules, e.g. Ss into Sj, with the formation 

 of molecules of intermediate complexity. With 

 monatomic molecules no such dissociation can occur. 

 With the 'tetratomic elements there is undoubted dis- 

 sociation ; but the changes are much less complicated 

 than in the case of sulphur, the tetratomic molecules 

 simply splitting up into diatomic molecules. It is, 

 however, to be noted that the highest temperature at 

 which silica tubes can be used is 1400° C. It is 

 possible that at still higher temperatures further dis- 

 sociation of the tetratomic elements would result, 

 accompanied by absorption phenomena similar to 

 those observed in^ the case of sulphur. — A. E. H. 

 Tntton : Monoclinic double selenates of the copper 

 group. This memoir deals with the four double 

 selenates of the series R2M(Se04)2,6H^O, in which 

 M is copper and R is potassium, rubidium, caesium, 

 and ammonium. A complete crystallographic and 

 physical investigation has been carried out, similar to 

 the work previouslv published concerning the mag- 

 NO. 2643, VOL. 105] 



nesium, zinc, iron, nickel, and cobalt groups, and to 

 that on the analogous double sulphates. 1 he results 

 confirm the conclusions derived Irom all the groups 

 previously studied, and in a peculiarly valuable 

 manner; for the copper-containmg group affords 

 crystals with morphological angles and elements and 

 physical constants which differ appreciably in their 

 absolute values from those afforded by the other 

 groups, in this respect xesembling the double sulphates 

 containing copper. Yet the relationships between the 

 values for the four salts are precisely the same, 

 leading thus to exactly the same general conclusions 

 as in the cases of those other groups. Every group 

 exhibits its own idiosyncrasies, and the copper groups 

 do so in a specially notable manner. Yet' the same 

 progression, according to the atomic weight and 

 atomic number of the alkali metal present, is exhibited 

 in the case of every property, whe'ther morphological, 

 such as the crystal angles and the topic axial ratios, 

 or physical,- such as the double refraction and the 

 molecular refraction; also the ammonium salt proves 

 to be practically isostructural with the rubidium salt. 

 The most recent work on the structure of the atom 

 and the further elaboration of Moseley's law connect- 

 ing the atomic number with the atomic structure and 

 complexity has only strengthened, the conclusion that 

 the author's results are a natural consequence of the 

 operation of Moseley's law : the progression in the 

 crystal properties , following the progression in thie 

 complexity of the alkali-metallic atoms, which exert 

 so dominating an influence in determining the struc- 

 ture and properties of these crystals.^H. G. Cannon : 

 Production and transmission of an environmental 

 effect in Simocephalus vetulus. The experiments were 

 undertaken in order to repeat, if possible, Agar's work 

 on the production and transmission of an abnormality 

 in Simocephalus vetulus. The magnitude of the 

 abnormality, which consisted in a chang-e in the 

 curvature of the valves of the carapace, could be 

 measured by the length/width ratio L/W. The results 

 indicate that the abnormality can be produced bv 

 feeding a culture containing practicallv no other 

 protozoon than Chlamydomonas. The L/W ratio was 

 found to be too variable to allow of its measurement 

 with sufficient accuracy on which to base considera- 

 tions as to the existence or non-existence of a 

 "reaction" to the abnormality of such a magnitude 

 as that indicated by Agar. The experimen-ts showed 

 that no antibody was produced to eliminate the cause 

 of the abnormality. — E. C. Grey : The enzymes of 

 B. coli communis, which are concerned in the decom- 

 position of glucose and mannitol. Part iv. : The 

 fermentation of glucose in the presence of formic 

 acid. Bv carrying out the fermentation of glucose by 

 bacteria in the presence of calcium formate the author 

 has been able to upset the normal balance which exists 

 between certain of the products, and thus to show 

 that thev are in reality formed bv seoarate enzvme 

 actions. Hitherto an anproximatelv constant relation- 

 shin ha<; been found between the formic acid and 

 carbon dioxide on one hand, and the alcohol and acetic 

 acid on the other. This relationshio is shown to be 

 rather accidental 'than essential. It results nrobablv 

 from the fact thnt the hvdroeen which arises from the 

 decomnosition of formic acid co-operntes in th-^ forma- 

 tion of alcohol, and thi's thf- two renrtions of alcohol 

 formation and carbon dioxide formation tend to keen 

 pace, with on'^' another. The addition of more formic 

 arid at the outset of the fermpnt.ition tends, however, 

 to prevent the production of formic acid from glucose, 

 and to destroy the ratio which normally exists between 

 this formic acid and the alcohol and acetic acid, thus 

 proving that these products arise by at least two 

 seoarate enzvme actions. Taken in coniunction with 

 the author's previous finding, that lactic acid is formed 



