524 Scientific Intelligence. 
The buds of the birch now began to expand, the tiie of the 
ap to diminish, and the oscillations of the mercury to become 
more decided and regular than before. The upper gauge ceased 
to vary May 14th, remaining stationary at zero. e lower one 
declined ty and varied greatly, but did not fall ec Zero 
until May 18th. On May 27th it also became stationary at 
The suction manifested by the birch was. very little, never sccliit 
ing nine feet of water, and continued only for a few 
To determine, if possible, whether — other force hati ‘the vital 
action of the roots was necessary to produce the extraordinar 
phenomena described, a gauge was attached to the root of a blac 
birch-tree, as follows: The tree stood in moist ground at the foot 
of the south slope of a ravine, in such a situation that the earth 
around it was shaded by the overhanging bank from the sun. 
root was then followed from the trunk to the distance of ten feet, 
April 26th. The pressure at once became evident, and rose con- 
stantly with very slight fluctuations, until, at noon on the 30th 
of April, it had attained the unequaled height of 85°80 feet of 
water. This wonderful result showed that the absorbing power 
of living birch rootlets, without the aid of any of the numerous 
helps imposed upon them m by ingenious philosophers, such as ex- 
halation, RE oscillation, dilatation, contraction, etc., wa 
8 e sufficient to acc count for the most essential of the curious 
Gobaiiad nd Paiva ie gene was s repeated, May 9th, and a ‘pres: 
sure of 49°52 feet o eae obtained, May 24th. ‘This is six and a 
half feet higher than was observed by Hales. The peculiar fea- 
tures of the pressure of the vine-sap are: its lateness in the sea 
son; its apparent independence of the wiather its uniform and 
moderate rise, day and night, to its maximum; its very gra 
decline to zero without an = marked oscillations, and its constant 
and almost unvarying suction of from 4°5 to 65 feet of water, 
manifested from June 20th to July soeh when the observations 
