145 



At the time the impurity of the water was first noticed, Dr. 

 Bacon had observed the large amount of oil in these Crustacea, 

 though, at that period, the animals were very probably not so 

 abundant as at present, and he had suggested this as a possible 

 cause of the difficulty. 



It being determined, then, from chemical and microscopical 

 evidence, that the impurity of the Cochituate water is owing to 

 the presence of the Crustacea, Dr. Hayes made some remarks, 

 of a practical nature, in relation to a remedy for the evil. It is 

 well known, that in lakes and other waters, all living animal and 

 vegetable forms exist in a definite relation to each other. If the 

 fish be withdrawn, vegetation, and the smaller forms of animal 

 life become predominant. If, by any means, the food of the 

 living inhabitants be increased, one or more species rapidly mul- 

 tiply. In Lake Cochituate, the great increase which has taken 

 place in the food of the Crustacea, has led to an excessive multipli- 

 cation of the species ; probably, a change in their ordinary habits 

 has been induced by the presence of oily food (like the remains 

 of fish) in the water, which, as scavengers, they select. Dr. 

 Hayes proposes, that fish, of all the species found in the New 

 England Lakes, be introduced into Lake Cochituate and the 

 Reservoir at Brookline, so as to stock them fully, and that these 

 waters be protected, by legislative action, from the visits of 

 anglers at all times. These oily crustaceans, which are the food 

 of fish, will then be reduced to their natural proportion, and the 

 water become clear and pure. While the impurities exist, it is 

 prudent for families to use for drinking, and if possible, for 

 cooking, only such water as has been passed through a filter. 

 Even coarse, temporary resorts of this kind, will remove much 

 that is offensive, while the better filters completely purify the 

 water. 



The Corresponding Secretary announced the reception 

 of the following letters, viz : — 



From the Cambridge Philosophical Society, (Cambridge, Eng.) 

 presenting its Transactions, Vol. IX., Parts I., II., III. ; — from 

 the Regents of the University of the State of New York, dated 



PROCEEDINGS B. S. N. H. VOL. V. 10 MARCH, 1855. 



