EXTRACTS OF PROCEEDINGS. 



Ivii 



this in turn produces turgidity of the cells, with a consequent 

 bypertrophied condition, resulting in the so-called " warts." 



Underground Temperature. — Mr. Henslow exhibited tables of 

 curves, showing the variations in the maximum, minimum, air, 

 and underground temperatures at a depth of 12 inches for the 

 preceding three months, taken by him at Ealing. The features 

 brought out by comparison were : (1) The much slighter oscilla- 

 tions in the subterranean temperatures than in the other three ; 

 (2) That while the subterranean varies with a maxima and 

 minima when their fluctuations are great, they often remain 

 unaffected when the latter are slight ; or (3) the curves may cor- 

 respond with one or other only of them respectively. Taking 

 the means for the three months, they are as follows : — 





Mean 



Mean 



Mean 



Mean 





Maximum 



Minimum 



Air 



Subterranean 





o 



o 



o 



o 



January . 



42 



30 



34 



37 



February . 



42 



30 



35 



37 



March 



45 



32 



40 



39 



Hence the mean subterranean temperature was in each case 1° 

 higher than the mean between the maximum and minimum of 

 each month. Comparing the subterranean with the minima on 

 January G the lowest minimum was 19°, but the subterranean 

 temperature never fell below 32°. On February 13 the lowest 

 minimum was 18°, the subterranean temperature being 33°, the 

 lowest for the month. On March 18 the lowest minimum was 

 also 18°, the subterranean being again 33°. Comparing sub- 

 terranean with maxima, on January 19 and 27 the highest 

 maximum occurred, viz., 51°, the subterranean reaching 40° on 

 both dates, while on the 31st it was 41°. In February there 

 were two high maxima, viz., on the 1st 54°, the subterranean 

 being 45° ; and on the 18th 56°, the subterranean being 44° on 

 the 20th. In March a series of six maxima ranged from 50° on 

 the 14th to 59° on the 28th and 30th ; the subterranean had five 

 corresponding maxima, reaching 46° on the 30th. 



Injurious Effect of London Fog. — Mr. Dyer laid before the 

 Committee a short scheme to indicate the line suggested for 

 inquiries into this matter : — 1. The natural history of fog con- 



