308 
SCOURING LANDS OF CENTRAL SOMERSET. 
depth (unlike rain or ditch water), are not affected by the 
temperature of the atmosphere. The former, therefore, have 
a uniform temperature throughout the year, although they 
appear cold in summer and warm in winter; whilst the tem¬ 
perature of the latter varies with the seasons, in consequence 
of which they really are warm in summer and cold in winter. 
Water which rises in the lias-clay, and is invariably cold in 
summer, having had to pass through beds of clay of con¬ 
siderable depth in its passage, becomes charged with abun¬ 
dance of saline mineral constituents. To these constituents 
alone, and not to the coldness, the scouring properties of such 
waters belong. 
Soft springs do not scour, for the simpleTeason that they 
are always poor in those saline mineral matters which confer 
medicinal properties upon the hard lias waters. If the con¬ 
trary be maintained, and no substantial proof be given that 
the water which is supposed to scour is really soft, I can 
only say that, in the course of my practice as an analytical 
chemist, I have frequently had waters submitted to me which 
were described as soft, and on analysis were found to be 
quite the reverse. 
ruThe water from peat land is always soft. It is supposed to 
contain tannin, or a similar astringent principle, in virtue of 
which it becomes a remedy when given to cattle affected by 
scouring. I do not question that the black ditch water from 
peat lands stays scouring; this, however, is not owing to any 
astringent principle which it is supposed to contain, but simply 
because, in comparison with spring water in scouring districts, 
it is remarkably poor in saline constituents. If hard water is 
withheld, one of the causes which in some—perhaps not a 
few cases—produce the evil is removed, and cattle soon re¬ 
cover when they are supplied with peat water. Tannin 
occurs in fresh vegetable substances, but as it is a compound 
which is decomposed with extreme facility, it cannot possibly 
exist in peat. Direct experiments, moreover, which I have 
made, proved the absence of tannin or similar astringent 
principles in peat, and showed to me that the dark-brown 
colour of peat water is due to certain combinations of ulmic 
and humic acid in which peat abounds. 
From the preceding remarks it may be gathered that one 
positive cause which produces scouring in cattle is the abun¬ 
dance of mineral and saline matters in certain springs of the 
lias formation. A still more complete insight into the na¬ 
ture of the mysterious complaint is gained by my investiga¬ 
tions on the character of the herbage of scouring pastures. 
{To be continued .) 
