Studies of Eozoon C ana Jens e 177 



that he thought it would be practically impossible to place 

 trees in confinement under the same conditions in regard to 

 heat, light, and ventilation as those in a state of nature, but 

 that, as deciduous trees are dormant throughout the winter 

 in temperate climates, the absence of light was not likely 

 to produce any sensible effect on them during winter. 



Feb. 28th, i8ist meeting. Mr. A. Smith mentioned results 

 lately obtained by Sir W. Thomson as to the rate ot a watch 

 placed horizontally and suspended by two vertical cords, 

 so that it can take up a vibration the rate of which depends 

 on the torsion of the cords. When this rate is less than 

 that of the balance of the watch, the latter gains, when 

 greater it loses. The change, however, is not gradual, as 

 might have been expected, but sudden, from the maximum 

 of gaining to that of losing. In the pocket chronometer, 

 exhibited by Mr. S. Smith, when the torsional vibration is 

 very slow, the gain is about i in 1250, or 70 seconds a day. 

 As the cords are shortened, the gain increases up to i in 50, 

 or 28 minutes a day. It then suddenly changes to a loss 

 of 28 minutes a day. When the watch is gaining, the balance 

 and watch vibrate in opposite directions ; when it is losing, 

 in the same direction. This can be easily perceived in a 

 chronometer, which only ticks when the balance is moving 

 to the right. 



Dr. Carpenter exhibited a specimen of Eozoon Canadenst 

 recently brought to England by Sir William Logan, in which 

 were two points of interest : (i) it is formed of lamellae, 

 which curve round in a natural manner to join one another, 

 and enclose the spaces elsewhere separating them ; (2) 

 because instead of being preserved in a serpentinous marble 

 it is imbedded in a homogeneous limestone. Hence it cannot 

 be due to any such reaction between calcareous and siliceous 

 constituents, as Professors King and Rowney have supposed. 

 Dr. Carpenter thought that no palaeontologist could doubt, 

 after examining this specimen, that it had an organic 

 origin, and was identical in character, both to the unaided 

 eye and under the microscope, with the ordinary forms of 

 Eozoon, though its minute structure was not well preserved, 

 p.c. M 



