April 8, 1892.] 



SCIENCE. 



201 



season, the relatively warmest district is near Iceland ; and the 

 barometer chart showed that close to the same region the barome- 

 ter is lowest. The reasons of these relations, which involve the 

 first principles of modern weather knowledge, were fully explained. 

 The more northern part of the Atlantic area interests us the most. 

 The whole region fi-om 40° to 70° north is constantly visited by 

 cyclonic depressions, and in order to throw some light on the 

 origin and history of these depressions, and of the storms which 

 they at times bring with them, various institutions have published 

 daily maps of (he weather in the Atlantic. The most complete of 

 these maps were published by the Meteorological Office for thir- 

 teen months, commencing with August, 1882. The last twelve 

 of these months have been carefully examined, and show no less 

 than 364 depressions in various parts of the ocean. Of these, out 

 of 63 which originated south of 40° north, only 16 had sufficient 

 energy in Ihem to cross the meridian of Greenwich, while out of 

 23 which originated further soiith only 11 crossed the Atlantic, 

 and these were not all felt as actual storms in England. The 

 practical outcome of obtaining telegrams from America has not 

 been satisfactory, but this failure has probably been mainly due 

 to the fact that the reports " have been neither numerous nor full 

 enough." This accurately represents the case at the present time ; 

 but we hope it is not too much to expect that, vvith our present 

 knowledge of the paths taken by depressions with regard to areas 

 of high pressure, some further advance may shortly be made in 

 predicting storms by means of more numerous and fuller tele- 

 graphic reports both from outward and homeward bound ships. 



— At the Brilish Institution of Electrical Engineers recently an 

 interesting paper, illustrated by experiments, was read by Professor 

 D. E. Hughes, F.R.S., on the value of oil as an insulator of elec- 

 triciiy, especially for currents of high potential and frequency. 

 Professor Hughes was led to recognize the merits and to suggest 

 the use of oil as early as 1858, after the failure of the first Trans- 

 atlantic cable, according to Engineering. It then appealed to 

 him that a fluid insulator with self- correcting properties would be 

 preferable to a solid insulator, such as gutta percha or india-rub- 

 ber, which, when once punctured by a spark, cannot close the 

 wound like oil, and thus renders the entire circuit useless until 

 the fault is removed. Professor Hughes made many experiments 

 on various oils at that lime, and embodied his results in a British 

 patent, dated Jan. 11, 1859, for "an improved mode of insulating 

 electrical conducting wires." The oil he had found most servicea- 

 ble was resin oil, which has an extraordinarily high resistance and 

 is somewhat viscid. He proposed to contain it in lubes of gutta- 

 percha or metal, through which the conductors, coated either with 

 a thin layer of gutta-percha or merely covered with fibrous mate- 

 rial, would run. The inventor ti-ied for two years to get English 

 electricians to adopt his method, but in vain; and, having to pro- 

 ceed to the Continent, he was obliged to abandon it. The late Mr. 

 David Brooks of Philadelphia subsequently introduced it in Amer- 

 ica, with great success and profit to himself, for insulating under- 

 ground telegraph wires. Oil is now used for insulating transfor- 

 mers, and it promises to be employed in a great many other ways. 



— At the meeting of the Belgian Academy of Sciences on March 

 6, Professor Spring announced, as we learn from Nature, that the 

 late Professor Stas had left, in an almost completed condition, a 

 long and important memoir describing the results of several fur- 

 ther stoichiomelrical investigations. It is entitled "Silver," and 

 will forthw ith be edited, presumably by Dr. Spring, and published. 

 It may he remembered that, after the publication of Professor 

 Stas's classical memoir upon the preparation of absolutely pure 

 silver and the atomic weight of that metal, doubts were thrown 

 by Professor Dumas on the validity of the work on the ground 

 that the silver employed was not free from occluded atmospheric 

 gases. Moreover, Professor Dumas expressed doubts as to the 

 bearing of the work upon the celebrated hypothesis of Prout, ac- 

 cording to which the atomic weights of all the other elements are 

 supposed to be multiples of that of hydrogen. For, if silver possessed 

 the atomic weight attributed to it by Pi'ofessor Stas, the atomic 

 weight of oxygen became 15.96 and not the whole number 16, and 

 consequently Pront's hypothesis in its original form would be nega- 

 tived. In order to set these doubts at rest, and to leave his work 



in a perfected condition, Professor Stas prepared a quantity 

 of siher with such extiems precautions that he succeeded in 

 odtaining it entirely free from occluded gases, and from even the 

 minutest traces of the materials of the vessels employed. So per- 

 fect is the purity of this silver that even when heated to the tem- 

 perature of the melting-point of iridium not a trace of sodium can 

 be detected in the spectrum of the vapor. With this silver he 

 repeated his former determinations of the atomic weight of the 

 metal, and it is satisfactory to learn that the final number obtained 

 is, as Professor Stas himself expected it would be, identical with 

 that formerly obtained. Hence the objection of Professor Dumas 

 cannot longer be entertained, and the atomic weight of oxygen 

 would indeed appear to be 15 96 and not 16, for the numbers ob- 

 tained by Professor Stas agree so remarkably that an error of 

 foui-hundredths of a unit would apparently be out of the question. 

 In addition to this important memoir. Professor Stas has also lelt 

 the data of a series of twelve separate determinations of the 

 stoichiometric relation of silver to potassium chloride, thematerials 

 for which were the pure silver just described, and a specimen of 

 potassium chloride, also prepared with a care and precaution quite 

 in keeping with the rest of the work of the great analysist. The 

 results of these determinations are described by Professor Spring 

 as agreeing in a most wonderful manner, and wid afford another 

 valuable base to which the atomic weights of many other cleme/its 

 may be referred. Besides these two memoirs, a third is mentioned 

 by Professor Spring, relating to the spectra of several metals which 

 Professor Stas obtained in the purest state in which these 

 metals have ever probably been seen. The whole of these memoirs, 

 consisting of about fifteen hundrel pages of manuscript, it is in- 

 tended to publish forthwith in three separate treatises. 



— Although preparations of lettuce have from very early times 

 had a reputation in medicine for their soporific properties, the 

 narcotic constituent of the jJant has never been ascertained with 

 any certainty. Various neutral, fatty, and waxy bodies separated 

 from the milky sap of difi'erent species of Lactuca have been fro »a 

 time to time described as compounds of medicinal value, but on 

 the other hand it has been denied that the dried milk sap, lactu- 

 carium, in spite of its narcotic odor, jjossesses any seJative action, 

 and in fact this preparation is no longer officinal in England or 

 the United States. It is therefoi-e interesting to learn in a com- 

 munication from the Research Laboratory of the Pharmaceutical 

 Society, read recently before the Clinical Society, that Mr. T. S. 

 Dymond has established beyond doubt the presence of hyoscya- 

 mine, the principal alkaloid of belladonna and henbane, not only 

 in the cabbage and Cos varieties of the common lettuce, L. sativa, 

 but also in the wild lettuce, L. virosa. The amount in the young 

 plants is certainly very minute, but in the officinal green extract, 

 which, according to the directions of the " British Pharmacopoeia,'' 

 is to be prepared from the flowering herb of L. virosa, the mydri- 

 atic alkaloid occurs to the extent of 0.03 per cent. 



— In a communication to the Paris Academic des Science, i». 

 Le Chatelier states that by means of his pyrometer he has discov- 

 ered that the temperatures which occur in melting steel and i'l 

 other industrial operations have been overestimated. These exag- 

 gerations, we learn from Engineering, the author atiributes to 

 several causes. When estimates of temperature disagree there is 

 a natural tendency to adopt the highest, because there is an in- 

 stinctive desire to establish some sort of proportionality between 

 the light emitted from a heated body, the amount of fuel required, 

 and the temperature. But the fact is that both the amount of 

 light emitted from a body, and the quantity of fuel required lo 

 heat it, increase much more rapidly than the temperature. More- 

 over, the calorimetric method has been that most frequent y 

 adopted for determining high temperatures. In this the assump- 

 tion is made that the specific heat of the iron rods or balls used is 

 constant, which is inaccurate. In the case of the flame of the 

 Bessemer converter Mr. Langley has fixed the temperature of the 

 issuing flame at '2,000° C, because platinum appears to uifit 

 rapidly in it. Mr. Chatelier has, however, found that platinum 

 does not fuse in the flame, but only appears to do so because it 

 alloys itself with drops of molten steel carried over by the 

 blast. 



