426 



NATURE 



[September 28, ign 



from the Eiffel rower, at nh. n.m. daily, for the benefit 

 of shipping in the Atlantic. The reports consist oi baro- 



metrii i eadin I and force, and state o 



at six stations in westi rn Europe, [i eland, \zori . 1 



Miquelon (New) Hand), to which a general summary of 



the weather is added, e.g. "Anticyclone over ral 



Europe, fine weather general; depression west of Iceland, 

 travelling toward the ea t." 



In view of the extensive use which is made of sulphur 

 as an insulator in electroscopes used in ionisation observa- 

 tions, a note in the August number of Le Radium, by Mr. 

 F. \Y. Bates, of the University of Montreal, on the effect 

 of light on the insulating properties of sulphur will be 

 read with interest. Mr. Hates finds that when exposed to 



light sulphur I lightly conducting, the conductivity 



increasing as the intensity of the light increases. This 

 property, he finds, is shared to a small extent by ebonite, 

 but amber appear- unaffected by light. He considers 

 that the importance of the subject justifies a more extended 

 study of it, and this he has commenced. 



Prof. A. Righi has two interesting papers in vol. xiv. 

 of the Mem. della R. Accad. di Bologna. The first deals 

 with the ionisation produced by the magneto-kathode rays. 

 It is found as the rays are more strongly developed, by 

 increasing the axial magnetic field, that the ionisation at 

 a given point in their path is diminished. The explana- 

 ton of this effect follows simply from the mode of forma- 

 tion of the rays ; the field holds in loose combination pairs 

 of oppositely charged ions which would otherwise escape 

 from each other's attraction, the number of free ions in 

 tli>- discharge ml" i- therefore diminished. Sir J. J. 

 Thomson has shown how complex are the phenomena in 

 the region in which the canal rays are usually studied ; it 

 therefore seems possible that other plausible explanations 

 could be given of the observed effects. The second of the 

 two papers deals with less explored ground, viz. the 

 influence of a magnetic field on the sparking potential. 

 The results here are so complicated that Prof. Righi thinks 

 more data will have to be collected before an explanation 

 can be given. As the magnetic field is increased the spark- 

 ing potential falls to a minimum, then rises to a maximum, 

 and finally decreases very slowly. The magnetic and 

 electric fields are parallel. Of other papers of physical 

 •I, one by Prof, \maduzzi deals with tin- photo- 

 electric effect in selenium, while Prof. P. Burgatti treats 

 of the vortical motion of a liquid, using vector analysis. 



We have received from the Patent Office Library a new 



Subject List of Works on Chemistry (including Alchemy, 

 Electrochemistry, and Radio-activity) in the Library oi thi 

 I'm ih Office." It is a work of 21S pages, and supersedes 

 a list published in 1901. A valuable feature of the list is 

 Hi' usi oi the dates of the volumes as one of the chief 

 it.-ms in the schemi ation ; under this system it 



to follow ih 1 nt of a subject or 



process, mid new publications fall naturallv into their 

 proper places at the end of the series. The classification 

 complex, and some practice would be needed 

 i<> trao quickly the volumes that one wished to consult: 

 but this is perhaps inevitable in view of the bewild 



nt hooks, journals, theses, dictionaries, and pamph- 

 1 ature of chemistry. 



A paper by M. Paul Sabatier on hydrogenation and | 

 dehydrogenatio has recently appeared in the | 



Revue Scientifiqtte. Original!) delivered in tin form nt a 

 l-i 1 in.' in tli'' German Chemical S01 ietj . the paper 1 ontains 

 a review <>i the new ind important branch of orj 



i develi ipi d during the past twelve | 



OL. 87] 



■ by the authoi and In- colleagues. II catalytic 

 action of the metals, and especialh, of finely divided n 

 has been utilised in .1 ven large numb,',- of 01 

 changes, and has proved ol peculiar value in the addition 

 and removal oi hydrogei re recently tin- catalytic in- 

 fluence ol .' numbei ol oxides, such as thorium dio 



1 been investi ed, and has proved to be ol 

 in effecting proo 1 condensation, such a- tin- con- 

 version ol acid- into ketones, and of alcohols into thiols, 

 esters, ethers tes. The summary now give 



both opportune and useful. 



The solubility of hydrogen in copper, nickel, and iron 

 is the subject of a communication by A. Sieverts to the 

 current number of the Zeitschrift ha physikalische 

 Chemie. The solubilities were studied for pressures up to 

 13 atmospheres, and over the temperature range 400° C. 

 to 1600 C. For a given temperature and pressure it was 

 found that the amount of gas taken up per unit weight 

 of metal was independent of the metal surface. At 

 constant temperature the solubility in both solid and liquid 

 metal is approximately proportional to the square root of 

 the gas pressure : at constant gas pressure the solubility 

 of the hydrogen increases with the temperature, a sudden 

 increase in the amount absorbed taking place at the melt- 

 ing point of the metal. As a consequence of the latter 

 property, there is a spitting when the metal solidifies, 

 copper giving off at its melting point about 2 volumes of 

 hydrogen, iron 7 volumes, and nickel 12 volumes. 



The August issue of the Journal of the Franklin Insti- 

 tute contains a paper by Dr. Charles Baskerville on the 

 chemistry of anaesthetics. In the case of chloroform 

 especially, and to a less extent in the case of other 

 anaesthetics, it is important not merely to ensure the initial 

 purity of the material, but also to store it under such con- 

 ditions as to prevent the formation of deleterious sub- 

 stances. The deterioration of chloroform is mainly due to 

 oxidation, as shown by the equation 



CHC1 ;i + O^COC1. + HC1. 

 This change is usually checked in the case of anaesthetic 

 chloroform by the addition of alcohol ; and it has been 

 shown that the initial oxidation of the mixture proceeds 

 entirely at the expense of the alcohol, and that the chloro- 

 form is not attacked until later. Nevertheless, it is 

 desirable to restrict oxidation by storing the liquid in 

 small bottles which can be opened as required, and to make 

 use of anactinic glass ; it has even been suggested that the 

 liquid should be stored in contact with nitrogen, and drawn 

 off by means of a syphon, in order to avoid all risk of 

 oxidation. 



An article in The Engineet foi September 22 deals with 

 hydraulic excavation on the Panama Canal. The m 



From hydraulic gold-mining as practised 



in California, and has 1 11 used on the largest scale in 



southward from the lower locks at 



Miraflores to opposite Corozal. Some 330,000 cubic yards 



of alluvial material were disintegrated between October and 



February last. rhe chief difficulty experienced durinj 



progress ol th work was the frequency with which limbs 



and trunks ..! rees, washed from the mud several 



ci ol ih' ground, were drawn into and 



'imp-. When this occurred, a coloured 



nan dived to the mouth of the pipe and extracted the 



I dii ' 'in', ol this 



mi thod ol exi m il ion is undoubted. 



Ax illustrated description ol tin- Trollhattan Hydro- 

 Powei Station, Sweden, appears in Enginci 

 foi Sepl mbei 22. I hi- station will represent, when com- 



