( 570 ) 
suddenly and on the sixth day it was as irregular as in living trees! 
Evidently the intermediate portion had suffered too much by this 
treatment, to function immediately, but on the sixth day it had so 
far recovered, that it could work again. It lived on until the end 
of December, as could be seen by the perfectly fresh bark. Now, at 
the end of January, it is dead. The crown, however, still looks 
healthy, as also do the buds. 
Although those facts, as far as 1 can see, do_ not permit of an 
explanation other than the one given here, a proof may still be 
adduced that such phenomena cannot be attributed to a change in 
the resistances. Such a change would moreover have to be of a 
very remarkable nature to be of any use as an explanation. 
Four manometers were attached to the trunk of a lilac tree 
(Sgringa vulgaris) 2 metres in height, and they were numbered in 
ascending order 1, 2, 3, and 4. After a short time they all showed 
an approximately equal “suction”, which oscillated with diurnal 
periods between 48 and 28 cm. of mercury. Although the differences 
were small, some times one was the highest, some times another. 
After 15 days, when I knew the course of the pressure curves 
sufficiently, stump 2 was killed, together with the piece of the stem 
to which it was attached. This was done by passing through it for 
an hour the discharges of an induction coil capable of giving a 
spark of 10 cm. long, without sparking in the secondary circuit. 
The stump and the portion of the trunk became heated to nearly 
60° C.: a few pieces of glass cement of that melting point, which 
1 had fastened to it, just began to melt. 
While the induction current was being passed, the suction of stump 
2 first diminished greatly, as a result of the heating, the other 
manometers remained constant. Soon the fall of the mercury 
in no 2 stopped and the suction increased again. After the interruption 
of the current the mercury rose higher than usual; this abnormally 
high suction subsequently persisted; no 2 afterwards followed the 
periods of the other manometers, which went on without hindrance, 
but sucked always strikingly more. How we can deduce from this 
the proof that this phenomenon is not caused by changes in the 
resistances, will be explained presently. 
Thus far the description of the experiments. I will now consider 
what may be deduced from the results. 
The course of the manometers in Sorbus proves that the water 
current in a living tree'is caused by quite different forces from those 
of a dead one. The result cannot be attributed to the imperfectness 
. of measurements. Most of these are the same before and after death 
