146 



VEGETATION OF THE PEAK DISTRICT 



[CH. 



the Peak District, it is easy to distinguish the vegetation of 

 the streams which flow over the non-calcareous or siliceous 

 soils and which have a very low mineral content from that of 

 the streams which flow over the calcareous soils and which 

 have a high mineral content. 



NON-CALCAREOUS WATERS 



The late Mr Ackroyd (1899 : 120), formerly the Borough 

 Analyst of Halifax, has published figures giving the composition 

 of the waters of a reservoir supplying that town ; and this 

 analysis is useful as it is typical of the whole of the non- 

 calcareous waters of the sandstones and shales of the Pennines, 

 including the Peak District. " The matters dissolved consist 

 of mere traces of inorganic bodies, and a small amount of 



peaty acid These waters are very soft, ranging from two to 



three Clark's degrees 1 ; and the hardness is of a permanent 

 character 2 , i.e., it is not appreciably lessened on boiling." The 

 following is Mr Ackroyd's full analysis : 



SWAMPS (OR MARSHES) ON THE SANDSTONES AND SHALES 



The larger streams of the district have their sources on 

 the peat moors, the smaller ones on the hill slopes. In the 

 former case, the sources of the streams occur either in the 



1 A Clark's degree is one grain of carbonate of lime (CaC0 3 ) per gallon, or 

 its equivalent of other lime (calcium) compound. 



2 Permanent hardness of water is due to sulphate of lime (CaS0 4 ), tem- 

 porary hardness to carbonate of lime (CaC0 3 ). 



3 15-43 grains = 1 gram; 0-22 gallons = 1 litre. 



