1883 .] Analyses of Books. 491 
himself. It was his task to search out fadts, and leave their 
coordination to others. 
Dr. Barrington has fulfilled his task ably and conscientiously, 
and has produced a book which deserves a favourable reception 
not alone within scientific circles. 
Proceedings of the Bristol Naturalists' Society. New Series, 
Vol. IV., Part I. (1882-3). 
The first paper in this number treats on the “ Iron Turnings 
Galvanic Ceil and the supposed Influence of Points in the 
Liberation of Bubbles.” The author, Mr. A. M. Worthington, 
shows that the common notion that points and edges determine 
the formation of bubbles in boiling liquids, &c., is a mistake, 
and that the phenomenon observed is due to the appearance of 
bubbles near points and edges, which, from their very nature, 
indicate a rough and cavernous region of the surface. 
Mr. James A. White contributes a note on a colony of alien 
plants found on the slope of a hill at Kingswood. Within the 
compass of about 50 yards by 25 the author found twenty spe- 
cies alien to Britain, and seventeen others which — though met 
with in other parts of the country — were alien to the Bristol 
coal-fields. 
Mr. Worthington exhibited to the Society, and described, an 
apparatus for observing splashes. 
Mr. E. Wethered, F.G.S., F.C.S., read a paper on the porosity 
and density of rocks with reference to water-supply. The author 
points out a consideration not to be overlooked by the advocates 
of deep-well water for “ potable purposes.” * That is, in certain 
rocks the water may pass through joints and fissures, under- 
going little filtration, so that its freedom from organic impurities 
is not a matter of course. 
Two papers, “ Rainfall at Clifton in 1882 ” and “ Thirty Years’ 
Rainfall at Clifton,” both by Dr. G. F. Burder, F.M.S., are of 
general interest. A graphic representation of the rainfall be- 
tween the years 1853 and 1882 inclusive, shows apparently a 
progressive increase of this great enemy to British agriculture. 
From 1853 to 1859 the average downfall was 29 317 inches ; 
from i860 to 1869, 34-084 inches ; from 1870 to 1879, 36-524 
inches ; and for the three years 1880 to 1882, 39*919 inches ! 
For excess of rain the author considers that the ten years just 
* In justice to the author we must add that this strange expression occurs 
in a quotation from a Report of the late “ Royal Rivers Pollution Com- 
mission.” 
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