422 



NA TURE 



[March i, 1888 



M. L. Teisserenc de Bort discusses, in the Annales of t^e 

 French Central Meteorological Office for 1885, part iv. (Paris, 

 1887), the importance of the high barooietric pressures of Asia 

 for weather forecasts over Europe. The paper deals with various 

 types of isobars existing simultaneously over Asia and Europe, 

 illustrated by charts. The result arrived at is that European 

 offices would derive great advantage from daily telegrams from 

 Asia, especially from the stations already in existence in Siberia 

 which report to St. Petersburg by wire. Hitherto the idea has 

 generally prevailed that the movements of the atmosphere from 

 the westward were alone useful for the prediction of weather 

 changes over Europe. 



The Austrian Meteorological Office has just published its 

 yahrbuch for 1886. The service was established in 1847, and 

 the first volume contained observations for 1848-49. The new 

 series of volumes, of which the present is the twenty-third, began 

 with the year 1864. The stations now number 380, including 

 three abroad, and are closer together than in any other of the 

 larger systems ; there are no less than nine stations in Vienna 

 alone. Daily observations are published for eighteen stations ; 

 for all the others monthly and yearly resumes are given. The 

 Hungarian observations are published in a separate volume. 



The Pioneer of Allahabad mentions a circumstance connected 

 with two recent cyclonic storms which is worthy of the attention 

 of meteorologists. These storms struck the Scinde desert between 

 January 24 and 30, and passed in a straight line across the 

 continent to Cuttack at the rate of 250 to 300 miles daily. The 

 second continued unbroken across the Bay of Bengal to Burmah. 

 If the line they followed were prolonged straight westward it 

 would reach Vienna, which is about 3600 miles from Scinde. 

 There seems (says the Pioneer) to have been an unusually violent 

 atmosiDheric disturbance in Vienna in the early part of January, 

 so the time and the rate of travelling would agree with the 

 assumjition that the storms were identical with that disturbance. 



Two remarkable new fluorides of potassium have been dis- 

 covered by M. Moissan, the isolater of fluorine. Hydrofluoric 

 acid is well-known to be readily capable of combining with 

 neutral fluorides to form fluorhydrates similar to that of 

 potassium, KF . HF ; indeed it was by the use of this latter com- 

 pound that fluorine was eventually so successfully obtained in the 

 free state. Moreover, the formition of such compounds has been 

 completely accounted for by the vapour- density determinations of 

 Kletzinsky and Mallet, who have shown that the composition of 

 the molecule of hydrofluoric acid just above its boiling-point is 

 H2F2. But M. Moissan now shows that this double fluoride of 

 jjotassium is by no means the only one, that two others, KF . 2HF 

 and KF . 3HF maybe readily obtained in well-formed crystals. 

 When dry powdered KF . HF is placed in anhydrous hydrofluoric 

 acid, it disappears almost instantaneously, the liquid becoming 

 sensibly warm ; in fact, M. Moissan in a few moojents dissolved 

 five to six grammes in ten grammes of the acid. On cooling this 

 mixture to - 23° C. white crystals separated out ; these were 

 rapidly dried between filter paper, transferred to a platinum tube 

 closed by a paraffined cork, weighed and analyzed. The results 

 of the analyses indicated the composition KF . 3HF. The com- 

 pound was then synthetically prepared by mixing potassium 

 fluoride and the acid in these proportions, evading any sudden 

 rise of temperature ; the liquid was subsequently warmed to 85° 

 in a platinum capsule, but not a trace of hydrofluoric acid vapour 

 escaped, although that substance boils at 19°. Hence it was 

 ■evident that the HF was locked up in chemical combination, and 

 this was soon observed to be the case, for on removing the source 

 of heat, crystals began to form even while the thermometer indi- 

 cated 68° ; on resuming the ordinary temperature of the room, 

 the whole became a mass of interlaced crystals, which analysis 



proved to be those of KF . 3HF. These crystals are extremely 

 deliquescent, being decomposed by water into the free acid and 

 potassium fluoride, emitting the acid fumes in a humid atmo- 

 sphere, and dissolving in water with production of the most 

 intense cold. If they are suddenly heated with crystalline siliccn, 

 the mass becomes incandescent, and a violent disengagement of 

 silicon tetrafluoride gas occurs. The stability of this fluorhydrate 

 was strikingly shown by placing a few crystals in vacuo, when 

 even after two hours the manometer only showed a difference of 

 O'Oi m. In a somewhat similar manner the compound KF . 2HF 

 was isolated and found to be a liquid at 105°, but crystallizing in 

 the cold. It is to the formation of these fluorhydrates that 

 M. Moissan attributes the preservation of his fluorine-isolating 

 apparatus, and the regular evolution of gaseous fluorine during ; 

 the electrolysis. 





During the last two or three years an extensive search for 

 natural gas has been made in the United States. In a paper on 

 the subject, just issued by the U.S. Geological Survey, Mr. J. 

 D. Weeks says the results of this exploration indicate: — (i) That | 

 along the Atlantic coast, east of the Appalachian Chain, includ- ( 

 ing in this term the Green Mountains, no gas is found, or, if J 

 found at all, in such small quantities as to indicate that it is of' 

 comparatively recent origin. It is a^so found in such horizons,! 

 and under such conditions, as to give but little evidence that it | 

 is in such storage reservoirs as to promise any considerable sup- 

 ply, (2) That the chief sources of the supply of natural gas in I 

 the United States are to be found in the Mississippi Valley, and, - 

 so far as present explorations show, in that portion of it east of? 

 the Mississippi River. The chief localities that had assumed * 

 any prominence as gas-centres at the close of 1886 were in 

 South-Western New York, Western Pennsylvania, North- % 

 Western Ohio, and Central Eastern Indiana. To these may 

 be added a locality in Michigan and one in Eastern Kansas. 



In the report of the U.S. Commission of Education for the 

 year 1885-86, just issued, it is stated that seldom in the history 

 of the United States have superior institutions of learning 

 occupied so large a share of public attention or given signs of 

 such vigorous and fruitful life as at the present time. Among 

 these institutions are classed schools of science, pure and applied, 

 which, according to the writer of the report, "have greatly in- 

 creased the provision for superior instruction, extended its 

 province, and borne an important part in the adjustment of its 

 processes to the demands arising from the extraordinary increase 

 of scientific knowledge and its applications to the leading 

 industries of modern times," 



We have received the annual address to the Asiatic Society, 

 Calcutta, delivered by the President, Mr. E, T. Atkinson. 

 Speaking of the Sui'vey of India, Mr. Atkinson says that most of 

 the operations connected with it during the past year have been 

 devoted to remunerative as distinguished from purely scientific 

 investigation. In many districts the survey has been cadastral 

 with a record of rights. The Baluchistan parties have done a 

 considerable amount of large-scale work around Quetta and 

 towards the Khwajah Amran range, and are now engaged on the 

 half-inch survey of that province. The Himalayan party has 

 been working under Colonel Tanner towards Kulu, and the 

 Andaman party has completed the survey of the coasts of the 

 Nicobars. 



We have received the "Geological Record f jr 1879," containing 

 an account of works on geology, mineralogy, and palaeontology, 

 published during the year, with supplements for 1874-78. The 

 volume is edited by Mr. Whitaker and Mr. W. H. Dalton, and 

 published by Messrs. Taylor and Francis. In the preface Mr. 

 Whitaker explains that as the position of editorofthe " Geological 

 Record " has proved to be one that can be held only with great 



