294 Royal Society. 



The odour which accompanies the electrolyzation of water, he 

 observes, is only disengaged at the positive electrode. He also finds 

 that the odoriferous principle can be preserved in well-closed glass 

 bottles for any length of time. The only metals which yield this 

 odour are gold and platina ; but dilute sulphuric, phosphoric, and 

 nitric acids, and from aqueous solutions of several of the salts, also 

 disengage it. Raising the temperature of the fluid to the boiling 

 point prevents the odour from arising ; and the addition of com- 

 paratively small quantities of powdered charcoal, iron, zinc, tin, lead, 

 antimony, bismuth or arsenic, or of a few drops of mercury, to the 

 odorous principle contained in a bottle, immediately destroys the 

 smell ; and the same happens when platina or gold, heated red-hot, 

 is introduced into the vessel containing that volatile substance. 



May 14. A paper was read, entitled, " Tables of the Variation, 

 through a cycle of nine years, of the mean height of the Barometer, 

 mean Temperature, and depth of Rain, as connected with the pre- 

 vailing Winds, influenced in their direction by the occurrence of the 

 Lunar Apsides, with some concluding observations on the result." 

 By Luke Howard, Esq., F.R.S., &c. 



From the Tables here given, the author draws the following con- 

 clusions : 



1. The barometer is higher under the lunar apogee, than under 

 the perigee ; the mean height in the former case being 29'84517, 

 and in the latter, 29' 75542. 



2. The mean temperature is lower under the apogee than under 

 the perigee; that of the former being 48 0> 7126, and of the latter, 

 49'0356. The mean of the whole year was 48'7126. 



3. The rain of the weeks following the apsis exceeds that under 

 the perigee ; but with two striking exceptions in the annual result 

 of nine years, the one in the wettest, and the other in the driest 

 year of the cycle. 



With regard to the winds, the author remarks that those from 

 the north, north-east, and east, prevailed under the apogee on 38 

 days, under the perigee on 21 days; and those from the south, 

 south-west, and west, prevailed under the apogee on 20 days, 

 under the perigee on 38 days. 



It appears, therefore, that in the climate of London, the moon, 

 in her perigee brings over us the southern atmosphere, which 

 tends to lower the density and raise the temperature of the air, 

 occasioning also a larger precipitation of rain. In the apogee, on 

 the contrary, there is a freer influx of air from the northward, a 

 higher barometer, a lower temperature, and less rain ; subject, 

 however,' to a large addition of rain under this apsis twice in a 

 cycle of nine years, at the times when also the extremes of wet and 

 dry take place on the whole amount of the year. 



A paper was also read entitled, " Experimental Researches into 

 the strength of Pillars of Cast Iron, and other materials." By 

 Eaton Hodgkinson, Esq. Communicated by Peter Barlow, Esq., 

 F.R.S., &c. 



The author finds that in all long pillars of the same dimensions, 



