175 



Mr, Frank Bridgman and Mr. Brooke U. Lacy were ballotted for, and elected 

 members of the Club. 



The Secretary read a communication from the Eev. H, G. W. Aubrey, des- 

 cribing a new form of turpentine bath for microscopic slides which he had 

 lately designed, and which was sent to the meeting for examination. 



Mr. Greenish thought that one objection to the use of this bath would be the 

 large surface of turpentine exposed to the air, as this would be likely to cause a 

 deposition of resin. Turpentine exposed in this way would be sure to oxidise. 



Mr. Golding noticed that provision appeared to have been made against this 

 by a piece of india-rubber running all round the top, so that the bath would be 

 quite air tight when the cover was fixed on. 



The President said that some years ago he had occasion to soak objects in 

 turpentine for the purpose of decolorizing them, and he used to place them 

 between pieces of glass, which he tied together, and then lowered into the 

 turpentine with a piece of string. After remaining there as long as was re- 

 quisite, he drew them out, and then mounted them in balsam in the usual 

 manner. The Eev. Mr. Aubrey's invention appeared to be for doing the same 

 thing in a more convenient and elaborate manner. 



The thanks of the meeting were voted to Mr. Aubrey for his communication . 



Mr. Locke thought that he need not say that the matter of mounting objects 

 dry, and so as not to spoil afterwards, was one of very great importance. Most 

 persons present had probably experienced the great annoyance of finding that 

 things which they thought were nicely mounted presently became damped and 

 "were utterly ruined. He thought, however, that he had, after many endeavours, 

 at last contrived a plan whiah, so far as preventing this evil was concerned, he 

 believed was perfect. His process was a simple one — lie took an ordinary elastic 

 india-rubber band of the same size as the glass cover it was intended to use and 

 put it upon an iron plate ; he then held it for a sliort time over the flame of a 

 spirit lamp until the under side of the ring was frizzled. This being done, he 

 turned it over on the iron plate and fried the other side, after which he allowed 

 it to cool, and then dropped it into a glass of water; it was then ready for use. 

 He next took a slide, and having dried it thoroughly, took the india-rubber circle 

 out of the water and put it into its place on the slide, then dried it carefully over 

 the lamp to extract all the moisture from it, and taking the scales or diatoms it 

 was desired to mount, he put them upon the covering glass, and laying this upon 

 the softened ring, pressed it down with the finger, which caused it at once 

 firmly to adhere, and as there was no cement used andthe ring did not evaporate, 

 the result was a perfectly dry mount. Some time ago he had two slides from 

 Mr. Swift to experiment upon ; they were utterly ruined by damp, but he took 

 them to pieces, and having contrived an oven in which to dry tliem, he allowed 

 tnem to remain there for five or six hours, and then mounted them again in the 

 manner described, and no signs of damp have since appeared, so that he believed 

 it had been perfectly successful. Bands could be easily procured of all sizes, and 

 if treated in this way, they would adhere firmly both to the slide and the cover 

 by themselves. The slides which he had brought with him to the meeting as 

 specimens had been finished about three months. He also wished to direct 

 the attention of the members to a simple method of altering the illumination 

 from direct to oblique which lie had designed and adapted to a flaicroscope then 

 in that room. 



The President proposed a vote of thanks to Mr. Locke for his communication. — 

 Carried unanimously. 



