THE BREAKING OF THE SHROPSHIRE MERES. 
BY WILLIAM PHILLIPS, F.L.S. 
(Continued from page 63.) 
The importance of this periodical breaking in large bodies of 
fresh water is evident in connection with the vital question of 
obtaining and storing supplies for domestic use. Much incon¬ 
venience has been caused in very many places, and methods 
discussed by which it might be prevented, but without arriving at 
any conclusive result. For eleven months in the year the water of 
a mere or pool might remain as pure as could be desired, and 
artificial reservoirs supplied from it through carefully constructed 
filter beds, yet still so minute are the reproductive organs of these 
minute algae that a few may pass through the filter, establish a 
colony, small at first, but capable in time of contaminating the 
whole store. The influence of sunlight in promoting their rapid 
growth is a significant factor in the question of prevention which 
those whose province it is to deal with such matters will do well to 
bear in mind. Covered reservoirs may check, if not prevent, their 
growth. 
There is every reason for believing that the breaking is a 
sanitary remedy of nature for removing other and worse contami¬ 
nations arising from the autumnal decay of organic matter, both 
animal and vegetable, occurring in the purest lakes and pools. 
This view is confirmed by the following statement of a competent 
chemist, Mr. T. P. Blunt*:—“ Algce, consisting as they do to a 
very large extent of green matter, called chlorophyll, depend for 
their development and growth upon the presence of carbonic acid, 
which they find dissolved in the water. Under the influence of 
light they decompose the carbonic acid, setting free the oxygen, 
which purifies the water and renders it fit for supporting animal 
life. The oxygen thus liberated adheres in bubbles to the algie, 
causing them to rise to the surface, into a fuller and stronger 
light.” 
* Mr. Blunt was one of the committee appointed by the Caradoc Field 
Club to investigate the phenomena of breaking in 1880. 
June, 1893. 
