366 



land, Jr., Mr. L. B. Stone, and Mr. Theodore Lyman, 

 were chosen a Committee for this purpose. 



The Secretary announced the resignations of the Cu- 

 rators of Entomology and Ichthyology, Messrs. Durkee 

 and Atwood. 



Dr. S. A. Green was elected a Resident Member. 



April 21, 1858. 



The President in the Chair. 



Dr. C. T. Jackson, referring to a communication made by Mr. 

 Green at the last meeting, upon the structure and composition of 

 Fish Scales, reminded the Society of the discovery of Fluorine 

 as a component of the scales of Ganoid Fishes, an account of 

 which he had some years since laid before the Society, (see Pro- 

 ceedings, vol. V. p. 92.) He had found a sufficient amount of 

 Fluorine in twenty-five grains of Gar-pike scales to etch a sen- 

 tence in glass. This discovery allied the scales of the Ganoids to 

 the enamel of teeth. Fluorine had before been found in fossil 

 fishes, but it was believed to be the result of infiltration from the 

 soil. 



Dr. A. A. Hayes presented a specimen of Cannel 

 Coal from a locality nine miles below the Kanawha 

 River, Virginia ; and made some general remarks upon 

 the products of coal distillation, illustrating the subject 

 by exhibition of some of the products. 



Dr. Charles Pickering read some memoranda formerly made 

 by him on the stinging power of the Physalia ; found to reside 

 in the blue bead-like knobs of the long cords which the animal 

 keeps continually letting down and drawing up. Under the 

 microscope, the surface of these knobs was observed to be occu- 

 pied by minute cells or vesicles, each containing an elastic hair- 

 like filament, " coiled up like a spiral spring." When touched 

 with the finger, the filament uncoils and shoots forth into the 



