232 THE Microscope. 
B. L. Oviatt then showed how to “Section fresh Cartilage,” by 
imbedding in paraffine, and using serum or normal salt solution 
sections could be made and preserved without shrinking in picric 
acid and alcohol. 
That inveterate inventor, Mr. E. H. Griffith, then showed 
several new devices, viz: An aid in focussing objectives, which con- 
sisted of a wire running through a slot along the objective and 
fixed with a set screw when the latter is once focussed, thus per- 
mitting its return by racking down until the end of wire touches 
the slide. It is very convenient where one is arranging diatoms, 
etc. Second, a “Mechanical finger, two for a penny,” a piece of 
brass plate, with a hole in one end, slipping over objective and 
bent at the other, to carry needle or whisker ; also, Filonite cells 
made of celluloid which can be thus made true and yet easily 
changed by slight heating, and much cheaper than glass. 
“ Optical Errors and Human mistakes,” a paper by the opti- 
cian, Ernst Gundlach, was read. Opticians have been constantly 
at work desiring to improve. their objectives ; both in the correction 
of the spectrum and in the glass. Some English makers got out a 
glass about twelve years ago, claiming an improvement, but an 
order from Mr. Gundlach was never filled, and he understood that 
the glass was too soft. From the best he could leara, he feared the 
same fate would meet the latest claims in Germany. He regarded 
the advance which was claimed in superiority of the new objective 
was owing to their fire lenses and not so much the quality of the 
glass. 
Dr. Blackham said that years ago Mr. Spencer told him the 
next great improvement in objectives must be in the glass compos- 
ing the lenses, and that he had experimented in that direction, 
but the glass thus made was too soft and deteriorated by the air 
alone. Dr. Blackham feared that the present claims were exagger- 
ated. He thought that the eye pieces should be improved. Prof. 
Burrill also spoke in a similar strain. 
“Photo-Micrograph vs. Micro-Photograph,” by <A. Clifford 
Mercer, in which he gave his researches into the origin of the 
words and declared in favor of the first as being the older and 
and proper designation. Prof. Rogers also urged the use of ‘* Mik- 
ron,” in place of Micro-millimeter. 
Edward Bausch then exhibited ‘‘ The Inverted and Vertical 
