1878. ] Microscopy. 333 
least two weeks before the time of the meeting, in order that a cor- 
rect programme may be prepared. 
The invitation to the congress at Indianapolis was, on motion, 
accepted, and it was resolved that members finding themselves 
able to attend should give early notice to that effect to the secre- 
tary of the committee, at No. 413 N. East street, Indianapolis. 
Mr. Joseph McKay gave a demonstration of Prof. H. L. Smith’s 
method of dry mounting by means of a background of wax and 
a curtain-ring cell, showing the facility and elegance with which 
this method may be carried out 
Rev. A. B. Hervey described a New Method of Fluid Mounting — 
which he had recently devised. In his study of the alge and 
lichens he had been troubled, as others have been, by the difficulty 
of permanently mounting specimens while studying them, with- 
out waste of time or change of arrangements. Most of the 
methods of mounting either ruin such objects entirely or else 
require considerable time, care, and special. appliances that are 
troublesome to a busy student; and therefore instructive speci- 
mens are often neglected and lost. The objects may be trans- 
ferred from water to Farrant’s solution of gum and glycerine and 
mounted without delay, but the structure is not well preserved 
and air bubbles are likely to be obstinately present. The objects 
show best in distilled water, sea water, camphor water, etc.; and 
to mount them instantly and with uniform success he prepares 
cells of the gum and glycerine solution put on by means of the turn 
table in the usual way. Having made cells of the required depth, 
and laid them aside until thoroughly dry, the inner half of the 
width of the cell is varnished on the turn table with gold size, 
which is also allowed time to dry perfectly. Objects in water 
are arranged and covered in these cells with ease, and are ready 
after lying aside for a time varying from a few minutes to a few 
hours, to receive a coat of gold size or other varnish, the fluid 
that exudes from the cell in pressing down the cover glass having 
dissolved enough of the gum cell to hold the cover in position. 
It has not been found that the cell is too much affected by the 
fluid; but if it should be so the cell could be made of the usual 
bf 
cements, insoluble in water, and then coated with a thin layer of — 
um 
Mr. C. E. Hanaman demonstrated the use of the Nachét cam- 
era lucida, and quoted opinions from discussions at the Queckett | 
Club to confirm its superior facility of use as compared with the 
other forms of camera. : 
Dr. Ward presented the New Self-centering Tur n-table recently 
contrived by W. H. Bulloch, of Chicago, and remarked that this 
table seemed to combine all the really radical improvements that 
have been made in the turn-table up to the present tıme. The 
» 
early tables were more or less satisfactory varieties of the original 
Shadbolt form, and were arranged to be whirled ina variety of 
