12 VoELCKER on the Scouring Lands 



the reason why cattle who drink them scour. But this is not 

 the case ; the temperature, as such, has nothing whatever to do 

 with the scouring properties of drinking water. It is perfectly 

 true, however, that the hard lias-springs are invariably cold in 

 summer in comparison with rain, ditch, or peat water. In winter, 

 on the contrary, they are warmer than surface springs. This 

 shows that the lias-springs, which often issue from clay beds of 

 considerable 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 tempera- 

 ture of the latter varies with the seasons, in consequence of which 

 they really are warm in summer and ofcd in winter. Water 

 which rises in the lias-clay, and is invariably cold in summer, 

 having had to pass through beds of clay of considerable depth in 

 its passage, becomes charged with abundance 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 simple reason that they are 

 always poor in those saline mineral matters which confer medi- 

 cinal properties upon the hard lias- waters. If the contrary 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 fre- 

 quently had waters submitted to me which were described as 

 soft, and on analysis were found to be quite the reverse. 



The 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-land 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 recover when 

 they are supplied with peat-water. Tannin occurs in fresh 

 vegetable substances, but as it is a compound which is decom- 

 posed 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 



