282 PROCEEDINGS OF SOCIETIES. 
difficulty which remains to be got over—you do not see the 
object definitively. You have first to ascertain the spot where 
you make the analysis with the microscope, and then apply the 
spectroscope to the eye-piece. This remains to be improved 
on, and it occurs to me that it can be done by means of 
the binocular microscope. We found, too, some curious results 
from investigating opaque objects. In all spectral analysis the 
difficulty is to get a monochromatic light. . Generally we get a 
spectrum of some sort, but from the surface of many opaque 
objects the reflected light is perfectly monochromatic. 
The Presrpent remarked that in matters of this kind persons 
generally ran “neck and neck” with each other, and proceeded 
to announce that Mr. Browning had, like Mr. Huggins, been 
- engaged on the subject of the application of the spectroscope to 
the microscope, and that he had promised a paper on the subject 
which he hoped would lead to further investigation and discus- 
sion. Certainly the spectroscope made the microscope more 
valuable than before, and he had been greatly delighted by the 
results shown by the microscope with the spectroscope attached. 
Mr. Stack observed that the important paper of Mr. Huggins 
ought not to be allowed to pass without remark. In Mr. Sorby’s 
arrangement the prism was placed beneath the stage of the 
microscope, and the spectrum magnified, say, with a one-inch 
objective. By this means the absorption bands could be seen in 
infinitesimally dilute solutions of blood. After viewing these 
bands in an extremely dilute solution, with the help of the 
microscope, the same solution was tried with an ordinary spec- 
troscope of considerable dispersive power, and no absorption 
bands could be discerned. Mr. Browning at once suggested the 
cause, viz., that the dispersion was too great, and it was found 
that an inferior spectroscope of less dispersive powers enabled 
them to be seen. Considerable dispersion is necessary when the 
separation of closely adjacent lines is to be effected; but too 
much dispersion spreads and thins out delicate absorption bands 
to such an extent as to render them invisible. From experiments 
I made at Mr. Browning’s, I think it probable that a new form of 
direct spectroscope, recently devised and made by him for Mr. 
Gassiot, will be found suited to the display of very faint absorp- 
tion bands, without the assistance of a microscope. By the 
arrangements of Mr. Huggins, in which the spectroscope was 
used as an eye-piece, a more extensive range of experiments 
could be made, not only in viewing the spectra of opaque objects, 
but in noticmg the changes that took place in cell-contents, 
either through natural processes, or by the application of reagents. 
Dr. G. C. Watricu, M.D., F.R.S., read a paper “On the 
Structure and Affinity of the Polycystina.” (‘Trans.,’ p. 75.) Dr. 
Wallich added that as he had in this paper taken occasion to 
differ from some of Dr. Carpenter’s views upon the subject, he 
had written to that gentleman, inviting him to attend the meet- 
