Froifs. ] 3 



without once rising to the top. On the other hand if you keep the 

 frog under water for a long time in the summer, you will kill it. 

 It is explained thus. As long as the temperature of the water 

 is no more than about 47° or 48° frogs will live any length 

 of time under the water. In this state, being in a sort of torpor, 

 they breathe by the skin alone, which absorbs sufficient oxygen to 

 support their languid life. Raise the temperature of the water 

 and the activity of the frog increases, and he therefore needs more 

 oxygen than his skin can supply. He therefore begins to use his 

 lungs ; but they cannot do their work in water, therefore the frog 

 rises to the top, for if kept under water he will perish. As the 

 spring advances he rises occasionally to the surface to expel the 

 carbonic acid and absorb fresh oxygen in its lungs. As the heat 

 increases the risings become more frequent, till at last in hot 

 weather he lives chiefly on land. 



Frogs when acted upon by intense cold may be perfectly frozen 

 inside as well as outside, and yet they are not dead. If heat be 

 gradually applied, the freezing ceases, and in eight minutes 

 life is once more in full activity. 



Tuesday, November 6th, 1866. 



The Eighteenth Meeting of the Society was held at Mr. Hay ward's 

 House. 



Dale and Leaf were elected members. 



The exhibitions were : — 



Ripple-marked Slates and some Fossil Shells from the Lower Siliu^an. 



By R. B. Hatward, Esq. 

 Shark's Teeth . . . . . . By A. J. Evans. 



A Collection containing nearly all the different forms of silica imder the 

 three divisions : 1, Vitreous; 2, Chalcedonic ; 3, Jaspers. 



By the Pkesident. 



Mr. Yereker then read a Paper on the method of acquiring 

 languages proposed by Mr. Prendergast, a method based on 

 observation of the process by which a child acquires the use of 

 his mother tongue. 



