Mr. West on Natural Waters. 39 



when a large quantity of such water has to be collected for the 

 supply of a town. The upland streams, deriving their supply 

 from high and barren land, barren of all but moss and heather, 

 are more or less deeply coloured by vegetable matter derived 

 from peat. There has occasionally been much controversy 

 respecting this peaty water; and among those who have en- 

 tered keenly into this, both parties have been, I think, some- 

 what in the wrong. While those are mistaken who condemn, 

 in the gross and for every purpose, water tinged in any degree 

 with peat, or who maintain that it cannot be deprived of this 

 colour, they are equally so who treat such an impregnation as 

 not injurious to any of the useful qualities of the water. What 

 may be the exact effect on the human constitution of the small 

 quantity of soluble vegetable matter, of whatever nature, from 

 which the hill streams derive their colour, I do not pretend to 

 say ; but the water is unsightly, not only from the brown 

 tinge, but from the coloured froth formed by the bubbles of 

 air which escape on standing. These, in water in general, 

 break as they reach the surface ; but, from the viscidity 

 produced by the peat, they collect and remain, giving an un- 

 pleasant and repulsive appearance. 



Now, I hold an opinion, which has been confirmed by some 

 experienced medical men, that the salubrity of water, as a beve- 

 rage, depends less upon its absolute purity than upon its being 

 brisk and palatable. We know how palling to the stomach is 

 water which has been boiled and cooled, or has stood long in 

 open vessels ; yet, so far as the term * pure water' means water 

 free from the presence of other substances than water, such is 

 frequently more pure than when originally drawn. I appre- 

 hend, that though much in diet which is agreeable to the palate 

 is at the same time unwholesome, yet that will not commonly 

 perform its part well which is itself positively disagreeable. 



Again, in experimenting upon this peaty colour, either as 

 strong as it could be obtained, or in its common and more 

 dilute state, I found it closely to follow the habits of those 

 vegetable infusions which are prepared expressly for the colour 

 they impart. Thus it is found dissolved, not merely suspended, 

 passing any number of times through filtering-paper without 



