170 The Botanical Gazette. [March, 
found in a similar experiment a grape skin which sustained a mercury 
column 70™ in height for seventy-five days. The membrane is believed 
to have shown an absolute or nearly absolute resistance to filtration by 
atmospheric gases during the time mentioned in my experiment, sine 
the upper surface of the column and the tube showed a discoloration it- 
dicative of the decay of the coloring matter from the lower side of the 
membrane. The gas evolved during the disintegration would be of 
sufficient amount to allow the fall of the mercury column.—R. N, Day, 
Minneapolis, Minn. 
Hamamelis Virginiana.—Notes in a recent number of the GazETl 
regarding the dissemination of seeds of Hamamelis Virginiana reall 
my first acquaintance with its powers of propulsion. 
In August, 1890, a visiting friend to whom the plant was net 
brought a branch to the house and placed it over a mirror. The nest 
afternoon (some twenty-four hours later) as I was sitting alone in the 
room my attention was called to occasional cracking sounds which 
vestigation proved to be caused by the propulsion of these seeds. 
By evening most of the capsules were found to be empty, and those 
not so were emptied during the following day. No measurement 
were taken, but I distinctly remember that a number of the seeds ¥" 
thrown to the opposite side of a 17-foot room. 
I mention this as showing that the propulsive power is acquired : 
the capsule becomes dry, even though the stage of maturity re 
reached.—Bessiz L. Puram, Harmonsburg, Pa. 
