42 H. L. Smith on a new Binocular Eye-piece. 
re the oils were for the most part eae ge during the 
distillation, 313 c. c. of gas were obtained from 1 gram of the 
substance 
In the analysis of the organic substance, no attention was 
paid to theamount of sulphur contained. Even in the original 
rock, when melted with carbonate of soda, this element plainly 
shows —s and in the carbonaceous substance, containing 
3°17 p.c , 1 found no less than 0°81 p,c. Whether the 
iron Reva in the ash be there in sufficient quantity to unite 
with the sulphur and make pyrite, or whether, as is possible, 
ere be an overplus of sulphur contained in the organic sub- 
stance, is as yet undecided. 
Art. VIJ.—On a new Binocular Eye-piece for high powers ; 
by H. L. Surrn, Kenyon College. 
WHILE experimenting with the apparatus for illumination 
of opake objects under high powers of the microscope, a de- 
scription = which was cahervaaily published in this Jour- 
nal,* the idea occurred to me that by using a small rectangular 
prism for the reflector of the illuminator, and a side tube that 
could be attached to it at pleasure, a binocular arrangement 
similar to that now made by Mr, Nachet could readily be 
adapted to any monocular instrument. I sent drawings to 
Mr, Wales for this purpose, some time before the publication 
already alluded to, requesting him also, to try for the reflector 
a plate of parallel glass, in such manner that the light re- 
flected from one surface might pass up the side tubg, and the 
light transmitted through the glass, up the main tube. Upon 
further thought, I devised the eye-piece now to be described, 
in order to more equally divide the light in the two tubes; and, 
feeling satisfied after roughly trying it, that it would be mauch 
superior to the plan I had suggested to Mr, Wales, I desired 
aey to pve for a time the semanas of the apparatus for 
Thad sent him the pla’ 
vel t the Tisininator to public em I tried 
again the effect of an eye-piece constructed mainly as escribed 
ene whi wa tubes, and holding the Aesth ° 
place simply it; although I did not notice any in- 
Jurious reflecti e back surface of the glass plate, es 
hrow the fa proposed to make it sufficiently we ha 
oe from the posterior surface entirely out of fa 
correct for the the transmitted rays by making the 
* Vol. xl, No. 119, Sept. 1865. 
