PROCEEDINGS OF THE SOCIETY. 755 



specimens; this, however, he was prepared to deny, knowing from 

 experience that there was no difficulty in the matter. With regard 

 to Mr. Cheshire's suggestion of sticking the clean cover on a piece of 

 wax and letting it remain with the under side upwards until wanted, 

 he could only say that if a cover was left like that in his laboratory 

 for even two or three minutes it would get so coated with dust as to 

 need cleaning again before it could be used. The plan of cleaning 

 up the excess of glycerin by means of a brush was the one he usually 

 adopted. With regard to putting two rings of balsam, there were, he 

 thought, other things which would do better, and he should suggest 

 Miller's caoutchouc cement instead, if there was no glycerin upon the 

 slide. And instead of putting glycerin on the under side of the 

 cover a better plan was simply to breathe on the cover — it answered 

 quite as well and was much less trouble. In using a watchmaker's 

 eye-glass, a far more convenient way was to have it mounted upon a 

 piece of light spring wire fixed in a heavy block as a stand ; it was 

 then very easy to bend it over the object and apply the eye when 

 required, and the moment the head was moved away, it sprang on one 

 side without any attention being required by the worker. 



Mr. Cheshire said that notwithstanding the remarks of the last 

 speaker he must still persist in stating that there were some structures 

 which were absolutely destroyed by mounting in Canada balsam. For 

 instance, there was a certain part of the dorsal vessels, which contained 

 cells which could not possibly be mounted in balsam without destruc- 

 tion. Certainly, if any one could so mount them without he should 

 be very glad to see them. 



Mr. Groves said he would willingly accept the challenge, the results 

 to be shown in that room. 



Mr. Cheshire said the proposal to breathe upon the cover-glass was 

 just undoing the thing he had been advocating, and as regarded 

 the difficulty of keeping the cover-glass clean, if mounting was done 

 in such dusty places the cover might be placed with the under side 

 downwards if necessary. 



The President said they were very much obliged to Mr. Cheshire 

 for his remarks. There were doubtless some amongst them who would 

 derive useful hints from the communication. They would also be 

 much interested in seeing the results of the mounting in balsam con- 

 cerning which the challenge had been accepted. 



Prof. M. N. Dutt's letter was read, accompanying some white 

 powdery substance, found spread over a partly sandy and partly 

 rocky extent of land adjoining the city of Delhi, which, when sub- 

 mitted to microscopic examination, appeared to be a living substance, 

 and not simply lime and sand. The particles (to all appearances 

 particles of lime, (^c.) wlien examined witli a low power, presented a 

 wliite flfjcky a[»pearance quite unlike any particles of lime. On dis- 

 solving a little of the powder in a drop of pure water and examining 

 the solution with a high power, three and only tlirce kinds of objects 

 could bo detected, viz. ; (1) Crowds of rod-like bodies floating in the 



