97 [Jackson. 



February 1, 1865. 

 The President in the chair. 



Thirty members present. 



Dr. B. Joy Jeffries exhibited a diagram in illustration of 

 his remarks at the pre^-ious meeting, one half of which pre- 

 sented the appearance of the eye in its natural position, the 

 other half during accommodation. 



The President thought that the question was yet open to 

 discussion whether the change of form in the lens did not 

 take i^lace within itself by its own contractibihty, mthout 

 reference to any external force. 



Dr. C. T. Jackson presented a large and fine specimen of 

 Calcite, from Martinsbm-g, ^. Y. He remarked that the cal- 

 cite in that locality was found in two sets of veins very 

 nearly parallel to one another, and only three hundred yards 

 apart, in one of which the crystals were lenticular, and in the 

 other the si^-sided prisms were found. He frirther added 

 that the metalliferous veins of that section were found, as 

 Vanuxem first pointed out, either running in a north- 

 southerly direction, or in an east-westerly direction. Those 

 which ran in a north-southerly direction contained no lead, 

 while the other always contained highly crystallized galena. 

 Dr. Jackson thought this was ex23lained readily on the sup- 

 position that the veins were produced at two entirely distinct 

 periods. The galena, he beheves, was raised in vapor or 

 sublimed, instancing experiments to show that this must be 

 the case. 



The results of some experiments upon the penetration of 

 moulds into the interior of closed cavities, in continuation 

 of former remarks on the same subject, were commented 

 upon by Professor Jeffi'ies Wjman, as having a bearing upon 

 questions now raised of the origin of minute organisms. 



Six eggs were placed on a sand-bath and heated sufii- 

 ciently to coagulate the albumen, and until they had lost one- 

 fourth of their weight. Thus a clear air-space between the 

 inner membranes of the ^%% was made. They were then 

 placed in a ground-glass stoppered jar with a little water 



PKOCEi:DI>'GS B. S. ^^ H.— VOL. X. 7 FEBRUARY, 1866. 



