Mav 3, 1906] 



NA ruRt 



17 



the observations continued most of the time near the mean 

 in both respects. The second line of investigation is the 

 dntermination of the total solar radiation outside our atmo- 

 sphere, by observations with the bolometer and pyrhcliometer 

 at a station situated in a relatively clear and cloudless region 

 and at a considerable altitude. This work is being done 

 on .Mount Wilson, in southern California, and it seems 

 that the estimates it is hoped to obtain there will be so 

 close an appro.ximation to the truth that if a noiable 

 variation of solar radiation outside our atmosphere occurs 

 the results will show it. 



The much-debated ii-rays form the subject of a short 

 note by Dr. P. Stefanelli in the Kendiconto of the Naples 

 .'\cademy, xi., 12. Referring to Meyer's e.\periments on the 

 decrease of phosphorescence in sulphide of lime when placed 

 in the glass receiver of an air pump. Dr. Stefanelli con- 

 siders the effects to be attributable to the fall of tempera- 

 ture produced by the e.\pansion of the air, and not to depend 

 on the existence of n-rays for their explanation. 



In Nature of January ii (vol. Ixxiii., p. 246) Mr. C. E. 

 Henham pointed out that Swedenborg in his " Principia," 

 published in 1733, constantly regarded both heat and light 

 as ethereal undulations. Mr. I. H. H. Gosset, of St. 

 .\ubyns, Hove, now informs us that, as a matter of fact, 

 in the year 1719, fourteen years before he published his 

 " Principia," .Swedenborg wrote a treatise " On Tremula- 

 tion," in which he advanced the theory of ethereal un- 

 dulations as applicable to our vital forces, light, heal, 

 sound, &c. 



In the Philosophical Magazine for .•\pril. Prof. .Alfred W. 

 Porter discusses the inversion points of the Joule-Kelvin 

 effect for a fluid passing through a porous plug. The 

 paper is a simple and straightforward deduction from the 

 laws of thermodynamics. The condition that an in- 

 finitesimal difference of pressure on the two sides of the 

 plug should give rise to no " cooling " or " heating effects "' 

 is given by the equation Tdv'dT — v = o, and when the 

 pressure-volume-temperature equiition is given, this con- 

 dition determines a curve in the p,T or v,T diagram 

 formed by the inversion points. Prof. Porter's paper is 

 mainly taken up with examining the form of this curve 

 corresponding to various assumed equations of state, such 

 as that of van der Waals or Dieterici. From the form of the 

 curves it is shown that in general two inversion tempera- 

 tures exist for the same pressure, between certain limits 

 of pressure ; in the case of van der Waals's equation, the 

 maximum limit is nine times the critical pressure. Finally, 

 the author points out that the experiinental study of these 

 inversion curves affords a very valuable method of testing 

 the relative validity of different equations of state. 

 Theoretically also a knowledge of the inversion curve and 

 the equation of state referred to any given thermometric 

 scale afford sufficient data to determine the relation bttween 

 that scale and the absolute temperature. 



-iCCORDiNG to the annual report of the Badische .\nilin- 

 und Soda-Fabrik, the price of artificial indigo is now one- 

 third less than that of the natural nroduct, the yield of 

 which was last year so small that the requirements of the 

 eastern markets could not be satisfied. 



In the Far Eastern Review (vol. ii., No. 9), a monthly 

 engineering journal published at Manila, Shanghai, and 

 Yokohama, Mr. \. C. Hobble gives some excellent illus- 

 trations of the largest hydroelectric installation in southern 

 -Asia, at the Cauvery River Falls, in Mysore. There is a 

 fall of 400 feet. Power is transmitted at a pressure of 

 35,000 volts over duplicate 3-phase lines a distance of 

 92 miles to the Kolar gold mines. 



NO. 1905, VOL. 74] 



In the Chemiker Zeitung we read of a serious laboratory 

 accident to Dr. Franz Wartensbcrgcr, a German chemist, 

 who is credited with having discovered a new explosive 

 considerably more violent than dynamite, and to whom it 

 is said that the American Government offered to pay one 

 million dollars for the explosive, provided its discoverer 

 were able to suggest a suitable method of firing it electrically 

 instead of using a fuse. ;\s Dr. Wartensberger was experi- 

 menting with this idea in mind an unexpected explosion is 

 supposed to have taken place, and he was so badly hurt 

 that it is doubtful whether he will recover. 



The ash of the Vesuvius eruption contained, according to 

 Prof. Zinno's analysis, various quantities of silica, alumina, 

 lime, magnesia, iron, and manganese ; traces of ammonium 

 chloride were frequently found, but these may possibly have 

 been formed after the ash had fallen. No indications of 

 either free sulphur or of free acid were detectable. The 

 deposit of the ash is held to have been beneficial to vegeta- 

 tion rather than the reverse, especiallv in the growth of 

 vines, grass, and vegetables, a fact that has been observed 

 on other occasions. 



In an interesting note to the Chemiker Zeitiing for 

 .April 21, Dr. M. C. Schuyten, of Antwerp, directs attention 

 to the aifferences of temperature which are observable in 

 chemical drying cupboards. Dr. Schuyten was led to con- 

 sider the question experimentally from the fact that mercury 

 phenyldimethylpyrarolone bromide was found to melt in a 

 drying cupboard when the thermometer did not register 

 a temperature so high as its melting point. The tempera- 

 ture of the air in the cupboard was observed in the great 

 majority of cases to be very much less than that of the 

 walls and shelves ; a volatile liquid placed in a vessel in 

 direct communication with the case evaporated much more 

 quickly than when suspended by threads. From the 

 numerical data given variations of 20° C. and more are 

 noti'-eable. 



We learn from the Chemist and Druggist that the Com- 

 mittee on Ways and Means, which sat at Washington on 

 March 30, authorised a favourable report on the Free 

 -Mcohol Bill, w-hich removes the internal revenue duty from 

 denaturised alcohol for use in the arts and sciences. The 

 Bill has the approval of Commissioner Yerkes, and it is 

 estimated that the annual loss in revenue will not exceed 

 100,000/., and may not be more than 6o,ooo!. It is held 

 that the Bill will be of great benefit to manufacturers, and 

 will afford an enlarged market for farm products from 

 which alcohol is made. The sale of denaturised alcohol as 

 a beverage or for liquid medicinal purposes is forbidden by 

 the measure. 



The following particulars of two prizes offered by the 

 French Government may prove of interest to industrial 

 chemists :—(i.) The methylation of alcohol (prize of 20.000 

 francs), (i) The smell and taste of the proposed methyl- 

 ating addition must be such as to preclude the use of 

 methylated alcohol as a drink ; (2) the smell of the methyl- 

 ating addition must, however, not be so objectionable and 

 strong as to prove harmful to those engaged in the manu- 

 facture of or in industries using methylated spirits, that is 

 to say, the use of such bodies "as acetylene, asafoetida, 

 garlic, &c., is not permitted; (3) the method of methylating 

 adopted mav not leave any deposit on the wick or on any 

 part of the lamp, if likely to interfere with the process of 

 burning, as, for example, sea salt, sodium sulphate, alum, 

 tincture of aloeS, &c. : (4) the methylating additive may not 

 be separable by fractional distillation ; (5) it may not con- 

 tain any substance which will attack the metallic parts of 



