31-2 FRESH-WATER ALG^. 



" TMiere the pool 

 Stands mantled o'er with green, invisible 

 Amid the floating verdure, millions stray." 



By placing a drop of water in the field of the microscope, 

 and observing the merry evolutions of its multitudinous in- 

 habitants, we see that He who made them blessed them 

 with happiness. It has been long known, also, that by 

 subsisting on the dead bodies of larger aquatic animals, 

 they ^' thus limit,^^ according to Liebig, " to the shortest 

 possible period, the deleterious influences which the pro- 

 ducts of dissolution and decay exercise upon the life of the 

 higher classes of animals/' ^' The recent discoveries," he 

 adds, " which have been made respecting these creatures, 

 are so extraordinary and so admirable, that they deserve to 

 be made universally known." The most remarkable fact in 

 these discoveries is that the functions of animal life are 

 reversed in these animalcules, and that, instead of evolving 

 carbonic acid gas, as, by breathing, other animals do, they 

 evolve pure oxygen."^ The air-bubbles given out by water 

 in which these animalcules abound, contain such pure 

 oxygen that a small bit of deal match- wood in which a flame 



* See ' Blights of the AMieat and their Remedies,' published by the 

 Religious Tract Society. 



