2o3 



IIARDWICKE'S SCIENCE-GOSSIP. 



For the week ending August nth, the lowest 

 reading of the barometer was 29/63 in. on Sunday 

 morning, and the highest 29/98 in. on Monday 

 morning. The mean temperature of the air was 

 63 '9 deg., and ra deg. above the average. The 

 general direction of the wind was south-west. Rain 

 fell on two days of the week, to the aggregate amount 

 of o " 1 1 in. The duration of registered bright sunshine 

 in the week was 47*5 hours, against 41 "5 hours at 

 Glynde Place, Lewes. 



In September the isotherms run nearly east and 

 west across England. The mean average tempera- 

 ture across Wigtown, Dumfries, and Jedburg is 55 ; 

 across Lancaster and York to Flamborough Head it 

 is 56 ; across Liverpool, Derby, Retford, and 

 Lincoln, it is 57 ; across Swansea, Monmouth, 

 Reading, Hartford, and Ipswich it is 58 , and along 

 the S. W., the S. and the S. E. coast it is 59 . 



The rainfall differs almost in vertical lines from N. 

 to S., being about 5 inches on the W. coast, about 

 3 inches in a vertical line down the middle of the 

 island, and about 2 inches on the E. coast. 



SCIENCE-GOSSIP. 



The sharks reported to be locating the mouth of 

 the Mersey, to the great terror of sea bathers, turn 

 out to be dog-fish. 



A "Primer of Micro-Petrology," by Mr. W. 

 Mawer, is announced. This will be welcome news 

 to many intending students. 



M. E. L. Trouvelot, during the storm of June 

 24th, at Paris, succeeded in obtaining the photograph 

 of a flash of lightning, and submitted the proof to the 

 Academy of Sciences on the 9th inst. This flash which 

 seemed to connect the earth with a cloud subtending 

 an angle of 40° This flash appears divided in four 

 main branches, brilliant and strongly marked. But 

 there were others less visible, some so faint that they 

 could not be seen in the negative without the help of 

 a lens. The total number of the branches large and 

 small is thirty-seven. A microscopic examination of 

 the image of the flash shows that it is like a long 

 ribbon, taking all the forms which a ribbon might 

 present if plunged into a slowly moving liquid. This 

 ribbon seemed to be traversed vertically by a multi- 

 tude of rays more or less close together, and more or 

 less brilliant. They are seen almost everywhere upon 

 the flash, even upon its faintest ramifications. They 

 correspond in general with the fracture of the zigzags 

 which seem to make up the flash. 



" Nature " of August 9th, says : — A new gas pos- 

 sessing some remarkable properties, has been dis- 

 covered by Professor Thorpe and Mr. J. W. Rodger, 

 in the research laboratory of the Normal School of 

 Science. It is a sulpho-fluoride of phosphorus of the 



composition P S F 3 ; and is termed by its discoveries 

 thiophosphoryl fluoride. The best method for its 

 preparation consists in heating pentasulphide of phos- 

 phorus with lead fluoride in a leaden tube. It may 

 also be obtained by substituting bismuth fluoride for 

 the fluoride of lead, the only difference between the 

 two reactions being that the second requires a higher 

 temperature than the first. Again, when sulphur, 

 phosphorus, and lead fluoride are gently warmed 

 together, an extremely violent reaction occurs, but 

 if a large excess of the fluoride of lead be employed, 

 a tolerably steady evolution of the new gas occurs, the 

 excess of the lead salt appearing as moderator. It is 

 an interesting fact throwing considerable light upon 

 the constitution of the sulpho-fluoride, that it may 

 be obtained by heating together to 150 C. in a sealed 

 tube, as mixture of the corresponding chlorine — 

 thiophosphoryl chloride, P S C I 3 — a mobile colour- 

 less liquid and trifluoride of arsenic. The simple 

 exchange of chlorine for fluorine here brings about a 

 striking physical change, from a highly refracting 

 liquid to a colourless gas ; and now for the remark- 

 able properties of the gas. In the first place, it is 

 spontaneously imflammable. If it be collected over 

 mercury, upon which it exerts no action in a tube 

 terminating above in a jet and stop-cock, and the 

 latter be slowly turned so as to permit of its gradual 

 escape, the gas immediately ignites as it comes in 

 contact with the air, burning with a greenish-yellow 

 flame tipped at the apex with blue. If, however, a 

 wide tube containing the gas standing over mercury 

 be suddenly withdrawn from the mercury trough, the 

 larger mass of gas with production of a fine blue 

 flash, the yellowish-green tint being again observed 

 as the light dies away. If a quantity contained in a 

 tube over mercury be heated for a considerable time 

 complete decomposition occurs ; sulphur and phos- 

 phorus both being deposited upon the sides of the 

 tube and gaseous silicon tetrafluoride left. From a 

 spectroscopic examination, dissociation was shown to 

 occur at the lowest temperature of the electric spark. 

 The gas is slowly dissolved by water and appears to 

 be somewhat soluble in ether ; but alcohol and ben- 

 zene exert no solvent action upon it. Finally, the 

 colourless transparent gas was reduced to liquid 

 somewhat resembling the sulpho-chloride, by means 

 of Cailletet's liquefaction apparatus. 



Mr. W. T. Blandford, F.R.S., announces the 

 immediate publication of Part I. of his "Fauna of 

 British India," including that of Ceylon and Burmah. 



The South Shields Literary and Scientific Society 

 have started a new monthly, under the title of " The 

 Tyneside Review." It is very brightly written and 

 well edited. 



We are sorry to have to chronicle the death of 

 Professor H. Carvill Lewis, a young American 

 geologist who has made his mark even in British 



