122 HEALTH AND DISEASE 



through the soil it meets with various soluble salts of lime, magnesia, 

 and soda, all of which tend to make considerable modifications in the 

 quality of the fluid, to what extent may be gathered from the analyses 

 of several specimens of water which are given by Professor Axe, pub- 

 lished in the fourth volume of the Royal Agricultural Society s Journal. 

 December, 1893. Three samples will suffice, and it will be observed 

 that the first one is most remarkable for the amount of solid constituents, 

 especially common salt, which it contains. " At Woodhall Spa, in Lin- 

 colnshire, a \vater said to possess valuable medicinal properties yields 

 no less than 1542 '2 grains of saline matter per gallon, as follows: 



Grains per gallon 

 " Chloride of sodium (common salt) ... ... ... 1330'0 



Chloride of calcium ... ... ... ... ... 1 1 1 '0 



Chloride of magnesium ... ... ... ... ... 91 - 2 



Carbonate of sodium ... ... ... ... ... lO'O 



Total 1542-2" 



The next sample is drawn from the wells in the chalk at Croydon, 

 and is noteworthy for the large amount of carbonate of lime it contains. 



Grains per gallon. 



"Silica 1-2 



Carbonate of calcium ... ... ... ... ... 1 7 '8 



Carbonate of magnesium ... ... ... ... ... 1'4 



Chloride of sodium ... ... ... ... ... 2'0 



Sulphate of sodium ... ... ... ... ... CH) 



Total ... ... ... 23 T 3" 



This is a very hard water. 



The sample which gave the following analysis is from Sudbrook Springs 

 under the Severn : 



Grains per gallon. 



" Carbonate of calcium ... ... ... ... ... 13'6 



Carbonate of magnesium ... ... ... ... ... 5'4 



Sulphate of magnesium ... ... ... 3*2 



Nitrate of magnesium ... ... ... ... ... 0'6 



Chloride of magnesium ... ... ... ... - 8 



Chloride of sodium (with a little potassium) 3'5 



Total ... 27-1" 



Besides a considerable amount of chalk, this water is noticeable for 

 the number and variety of the salts of magnesia it contains. It is there- 

 fore classed with the magnesian waters. 



On the other hand, water collected from formations which are mainly 

 composed of insoluble rock, are naturally remarkable for their freedom 

 from saline constituents, as the two analyses of Woodland and Holm- 

 firth waters will show. 



