of Central Somerset. 11 



matter in the imperial gallon, or only one-fourth of the quantity 

 contained in the lias water. In good drinking water, of average 

 degree of hardness, the amount of mineral matters varies from 

 20 to 30 grains in the gallon, and soft waters contain only from 

 5 to 10 grains in the gallon. 



During the dry and hot summer months, cattle which drink 

 such lias water imbibe with it a very large quantity of mineral 

 and saline substances, which experience teaches disturb the 

 regular functions of the digestive organs, and cause the cattle to 

 scour. 



Composition of Spring -Water from Ford Farm. 



An imperial gallon wa* found to contain 



Organic matter *56 



Sulphate of lime .". 109'87 



Carbonate of lime 26*55 



Sulphate of magnesia 25'80 



Chloride of sodium 6' 65 



Sulphate of potash and soda .. .. 6*17 



175-60 grains. 



On comparing the composition of this water with that of the 

 Dunball Spring, a general similarity will be noticed. Both 

 springs contain an abnormally large quantity of mineral and 

 saline constituents which cannot fail seriously to affect the health 

 of cattle that drink them. The spring at Ford Farm is not quite 

 so rich in mineral matters as that from the Dunball cutting, but 

 it nevertheless contains a larger proportion of such matters than 

 many waters which, rising in the lias-clays, are well known to 

 possess aperient properties. The fact, therefore, that certain 

 waters in the lias-formation scour cattle, finds a full and satisfac- 

 tory explanation in the peculiar composition of the two preceding 

 springs. 



The saline mineral substances in these waters, of course, exist 

 in the beds from which the springs rise, or else they would not 

 be found in the water. The blue lias-clay, therefore, must be 

 regarded as the primary source from which the scouring pro- 

 perties of the water arise. In this sense it is, after all, the land 

 which causes the mischief. The large proportion of sulphates in 

 the springs of the lias-clay is worthy of notice, for it explains the 

 peculiar and disagreeable smell which at times characterizes 

 these waters. This smell is due to sulphuretted hydrogen a 

 gas which is generated when sulphates are brought into contact 

 with organic matters, free access of air being excluded at 

 same time. 



It has been asserted that the coldness of certain waters may be 



