Proceedings. 1 5 



an instrument as we have described.* It will be a difficult 

 matter to show any difference, in effect, between a transparent 

 body thus made self-radiant, and an opaque one illuminated 

 from above. 



Moreover, it may be that the effect of very oblique light, 

 giving a dark field, is really something more than we have 

 suggested. Long ago, Mr. Wenham devised various means of 

 obtaining oblique light for balsam or fluid mounts, and he con- 

 sidered that in many cases the light suffered total reflection 

 from the surface of the cover-glass and was thrown down 

 upon the object, thus in fact giving the effect of illumination 

 from above : only, however, with dry objectives. 



It is often difficult, if not impossible, to say whether an 

 image we see is truly positive or not. It seems not unlikely 

 that sometimes the object seen by such oblique light, really 

 shows by the reflected light from the cover. These are old 

 ideas but they should not be forgotten entirely. 



There is one remark I wish to add here for the mere purpose 

 of putting myself on record in this matter. I wish to say dis- 

 tinctly that I do not admit, and never have intentionally said, 

 that high angled glasses of the finest quality are always the 

 best for the most delicate work. I do say that as a rule they 

 are the best, and particularly for the resolution of fine lines or 

 dots in series. 



PROCEEDINGS. 



Regular meeting, Sept. 20th, 1878. The minutes of the preceding meeting 

 were read and approved. 



After several reports from special committees relating to matters of business, 

 two new members were elected — Mr. Benjamin Braman as an associate, and Rev. 

 Dr. W. Underwood, as an active member. The Secretary read a paper on 

 " Micrometry." 



The following resolution, proposed in this paper, was carried : 



^^ Resolved, that the New York Microscopical Society approve of the resolutions 

 adopted by the National Microscopical Congress, at Indianapolis, August 17th, 

 1878, making the l-ioo mm. the standard for micrometry in the U. S., and 

 recommend the same unit for universal use. " 



The Corresponding Secretary was directed to communicate with the various 

 societies, informing them of this action, and requesting their sanction for the 

 efforts of this society to secure an universal standard of micrometry. 



Mr. Whitehead opposed the plan suggested in the paper of having five stand- 

 ard micrometers throughout the country. He maintained that only a single true 



*A11 observers do not admit this. 



