February 9, 1905] 



NA TURE 



359 



passing is decreased. The action is altogether dilTerent 

 according to the direction of the discharge. Using a sparlc- 

 gap longer than 2 cm. and making the larger knob, of 

 the machine used, positive, the radiations had practically 

 no influence. With the smaller knob positive the radium, 

 in most cases, extinguished the spark. The phenomenon 

 is found to be due to the action of the & rays. Rontgen 

 rays do not produce this effect, even if their ionising power 

 at the spark-gap is some thousands of times greater than 

 that of the radium. Lenard rays are, however, effective. — 

 The slow stretch in indiarubber, glass, and metal wires 

 subjected to a constant pull : P. Phillips. When india- 

 rubber is subjected to a sustained pull of constant amount 

 it yields at quite a large rate, the stretch at any time (i), 

 after the estsblishment of the pull, being given by 

 a; = o + 6 log (, a and 6 being constants for the particular 

 pull exerted. For different pulls b is proportional to the 

 pull. When the pull is removed the indiarubber slowly 

 returns to its original length, the extension still remaining 

 at a time <„ after the removal being given by 



x = h log ((/tj, 

 t being the time which has elapsed since the pull was estab- 

 lished. These two results, for the slow stretching and 

 slow recovery of indiarubber, have also been established for 

 glass fibres subjected to sustained pull, but the magnitude 

 of the slow yielding is very much smaller. When annealed 

 wires of copper, silver, gold, or platinum are subjected to 

 a sustained pull they behave in some ways similarly to 

 indiarubber and glass, but there are some very decided 

 differences. If the pull is greater than a certain amount 

 (in the actual experiments about one-third to one-quarter 

 of the breaking weight) the stretch at any time (() after 

 the establishment of the pull is given by the same law 

 x = a+h log *, but below this value of the pull h is zero. 

 This law obtains up to the breaking strain of the wire, h 

 increasing very rapidly a little before the breaking strain 

 is reached. When the pull is removed, there is no appre- 

 ciable slow recovery like that occurring in indiarubber and 

 glass. Iron and steel wires show themselves to be excep- 

 tions to these rules. — Determination of Young's modulus 

 fadiabatic) for glass : C. A. Bell, with an appendix by Dr. C. 

 Chree, F.R.S. In this paper it is shown that errors in 

 the acoustical determination of Young's modulus for glass, 

 due to irregularities in the rods or tubes employed, may be 

 eliminated by applying to the measured length of each 

 free-free rod a correction given by the formula 

 ., /■' 5S 2-rz , 



J ^« ' 



in which 8S is the difference between the cross section at 

 the point s and its mean value, S,, for the whole rod. — 

 Some methods for studying the viscosity of solids : Dr. 

 Boris Weinberg:. The author has been carrying out in- 

 vestigations similar to those described by Prof. Trouton 

 and Mr. Andrews in their paper on the viscosity 

 of pitch-like substances (Proc. Phys. Sec, 1903). The 

 details of his experiments are, however, different. He has 

 worked principally with lead and has employed three dis- 

 tinct methods for determining the coefficient of viscosity. 

 Paris. 

 Academy of Sciences, January 30. — M. Troost in the 

 chair. — On some new experiments relating to the prepara- 

 tion of the diamond : Henri Moissan. In connection with 

 the study of the Canon Diablo meteorite, it appeared desir- 

 able to repeat the experiments on the formation of diamonds 

 in rapidly cooled cast iron, with especial reference to the 

 effect of sulphur and silicon in the ingot. The results 

 obtained with an ingot to which iron sulphide had been 

 added immediately before cooling were similar to those of 

 the earlier experiments, except that the yield of diamonds 

 was slightly greater. The addition of silicon had the same 

 effect, except that the formation of the dense silicon carbide 

 rendered the separation of the microscopic diamonds rather 

 more difficult. Drawings of four typical crystals are given. 

 — Synthesis in the anthracene series : MM. Haller and A. 

 Guyot. 7-hydroxy-7-triphenyl-dihydroanthracene condenses 

 very readily with amines and phenols, giving compounds 

 of the type 



(QH5I2 c( " 'NcCCeHjHQH, R), 

 NO. I 84 1, VOL. 71] 



in which R may be N(CH3),,N(C,H5)j, NH„, or OH. A 

 description of these substances is given. — The mixed treat- 

 ment of trypanosomiasis by arsenious acid and trypan-red : 

 A. Laveran. The injection of these substances has caused 

 the disappearance of the Tr. gambicnse in certain animals, 

 and hence the author regards this disease as curable in 

 certain cases, the most efficacious treatment being the suc- 

 cessive injection of arsenious acid and trypan-red. As the 

 curative doses of these substances are not far removed 

 from their toxic doses, this toxicity being variable with the 

 animal species, the doses to be prescribed must be rigor- 

 ously determined. This will be especially difficult for man. 

 — On the faculty possessed by cement strengthened with 

 iron of supporting large elongations : M. Considere. 

 Some doubt having been thrown on the earlier work of the 

 author on this subject by German and American writers, 

 details are given of some further experiments, the results 

 of which are in complete accordance with those of 

 the earlier work. — On the new short period comet 

 1904 e (Borrelly, December 28, 1904) : G. Fayet. Observ- 

 ations on this comet having now been carried on for a 

 month, the calculation of its orbit can be made with more 

 certainty. The results confirm those previously published, 

 the time of revolution being now determined at about seven 

 years. — A secondary shadow observed on the rings of 

 Saturn in October, November, and December, 1904 : M. 

 Amann and CI. Rozet. Between October 20 and the end 

 of December, besides the shadow of Saturn projected on 

 its ring a second shadow, narrower and less well marked 

 than this, was observed. It traversed the rings through- 

 out in the form of a curved line, and it was noted 

 that the portion of the rings between the shadow of the 

 planet and that now described appeared to be more brilliant 

 than the other illuminated portions of the rings. It is not 

 clear to what this extra shadow can, be due. — Remarks on 



a generalisation of M. Riesz : Emile Borel On the 



zeros of integral functions of infinite order, not transfinite : 

 Ed. Maillet. — On the precision of geographical positions 

 obtained in the field with the prism astrolabe : M. 

 Driencourt. This instrument, invented by A. Claude, has 

 already been tested in the Observatory of Montsouris, with 

 very satisfactory results ; it remained to be seen whether 

 the same accuracy could be maintained in field observations. 

 Details are given of some measurements made in Mada- 

 gascar showing the remarkable saving of time, without 

 loss of precision, resulting from its use. — On the self-regis- 

 tration of the ions of the atmosphere : P. Langevin and 

 M. Moulin. Owing to the existence of two kinds of ions 

 in air differing greatly in mobility, it is not possible to 

 register these on the same apparatus, although the same 

 principle is applicable. The theory of the apparatus with 

 some details of its construction are given. — On the temper- 

 ing of bronzes : Leon Guillet. The mechanical properties 

 of bronzes of varying content of copper, and after tempering 

 at varying temperatures, correspond very closely with the 

 changes of constitution brought out by the experiments of 

 Heycock and Neville. — A brown modification of colloidal 

 ferric oxide : P. Nicolardot. — On the chlorination of 

 methyl-ethyl-ketone : Andr^ Kling;. After trying the various 

 methods of chlorination of ketones, the [nethod found to 

 give the best yield is described in detail, the action of 

 chlorine in the presence of water and marble. The chief 

 product was CH,.CHCl.CO.CH3, boiling at 114° to 117°, 

 and furnishing the glycol CH3.CH.(OH).CH(OH).CH3 on 

 reduction. — The action of dilute nitric acid upon vegetable 

 fibres : M. Jardin. The use of a weak solution of nitric 

 acid, s parts of acid in 1000, is suggested for bleaching 

 flax. It presents certain advantages in regard to the time 

 and the amount of labour required, and leaves a fibre which 

 takes the dye in a perfectly homogeneous manner. — On 

 fiedlerite : A. de Schulten. This mineral is a hydrated 

 oxvchloride of lead, of a composition corresponding to 

 2PbOHCI,PbCI,.— On the salts of the Tchad region : H. 

 Courtet. — On the parasitism of Osyris alba : A. Fraysse. 

 In a preceding note some conclusions have been given on 

 the biology of Osyris alba and on the anatomy of its 

 suckers. In the present note is an account of the general 

 physiology of these suckers and the relations existing 

 between the parasite and its host. — On the changes of com- 

 position of the fruit of the Cucurbitaceje : Leclerc 

 du Sablon. — On the chemical composition and the significa- 



