Report of Committee of Investigation on Bog-flow in Kerry. 501 
makes an interesting observation on the dessicating effects of 
sphagnum on the air over mountain bogs. This is so great that 
onthe leeward of these bogs, at least in Norway and Nova Zembla, 
an aero-xerophytic (dry air) flora occurs. 
The immediate cause of an eruption of a bog is, according to 
- Klinge, the violent irruption of water into the bog from below. 
| In discussing Klinge’s views we may first point out that the 
mountain bogs of this country belong to his first class—those in 
which the decomposition of the vegetable matter increases from the 
surface downwards. The decomposed peat is heavier than water, 
and tends to accumulate at the bottom; the crust on which the 
growing plants are found is lighter than water, and floats on the 
top of the bog. It is between the crust and the lower layers that 
we should expect the most fluid portion of the bog to occur. 
We cannot agree that the crust is impermeable; the fact that 
bogs can be drained is opposed to such a view; nor do the pools 
which Klinge instances afford conclusive proof in its favour; they 
may be explained by a difference in permeability of the surround- 
ing peat, and that they are being drained of water, or have been 
supplied with it, it is possible, at different rates. 
The subject is discussed in the Report of the Commissioners on 
Bogs, some of the surveyors taking the same view as Klinge. Thus 
Mr. Townsend? states that strata of turf of a firm and close 
texture, impervious to water, exist in every bog; and he is 
“decidedly of opinion that the springs under the bog do not 
penetrate upwards through this substance, but that the wetness 
of bogs is caused by the rain-water falling on the surface, and 
lodging in the small cracks and indentures”’; the water slowly 
drains away by-the natural descent of the surface. A similar 
opinion was held by Mr. Longfield, who says that ‘the vegetable 
matter of which the bogs in his district (River Brusna) are com- 
posed is perfectly retentive of water, so much so that the numerous 
duck-pools and lodgments of water in bogs are almost all upon 
different levels”’; and he mentions “two considerable bodies of 
water at the distance of a few perches only from each other and 
yet differing 23 feet in level.’ Mr. Edgeworth remarks of certain 
1 Second Report Commission on Bogs, Appendix No. 7, p. 154, 1811. 
2 Tbid., p. 5. 
