1116 PROCEEDINGS OF THE SOCIETY. 



than the cover, for lifting the latter and adjusting it in mounting. 

 Several difficulties appear in the use of the wax as recommended, 

 and I now use what seems to me a more convenient form. An or- 

 dinary penholder, with a ferrule which is not split, is employed. 

 The ferrule is cut off to such length as to leave a short tube 1/4 in. 

 long on the handle. This tube is filled with wax in such manner as 

 to leave a well-rounded end ; this is easily done, by simple dipping. 

 A permanent handle is now ready for use at all times. In use, the 

 wax only requires to be applied very lightly to the centre of the cover, 

 when the latter may be lifted and placed in position without the least 

 difficulty. The advantages of this handle are : (1) Minimum contact 

 of wax and glass : (2) the specimen can be seen and its proper position 

 secured as the cover goes on ; (3) very slight pressure with a needle 

 seems to release the cover from the handle ; (4) there is the least 

 quantity of wax to clean off." 



Mr. Cheshire said he was not in the least disposed to criticize the 

 method suggested, though it appeared to him to have its disadvantages, 

 for if they had a contact on one side only the pressure would be so 

 unequally distributed as to be very likely to unsettle the object or to 

 displace it, particularly when working at the end of a penholder. 



Mr. C. Beck exhibited a compact form of Mr. Stephenson's Cata- 

 dioptric illuminator. 



The President said that those who saw Mr. Stephenson's original 

 apparatus would notice how very much more compact the one now 

 before them was. He had tried the former, and found it to work 

 exceedingly well. 



Mr. Kitton's and Mr. Kain's notes on Balsam of Tolu were read. 

 Mr. Kitton wrote : — 



" Since the publication of my note on Balsam of Tolu, I obtained 

 another sample of the gum. This was very different from the first, 

 which was darker in colour, not brittle, and dissolved freely in benzole 

 without residue. The second sample was brittle, and capable of being 

 pounded in a mortar. It was also soluble in hot benzole, which, on 

 cooling, deposited a very dark viscid mass, leaving a pale golden 

 brown liquid above. This is said to contain all the cinnamic acid, 

 the denser gum being Tolu, and which is only soluble in absolute 

 alcohol or chloroform. I tried it in the latter, but its very dark colour 

 made it very objectionable, excepting in the very thinnest film. 



" The lighter fluid was apparently about the same refractive index, 

 and I mounted several diatoms in it, which, in the course of a week or 

 two, showed a plentiful crop of crystals. It afterwards occurred to 

 me that heat would volatilize the cinnamic acid. I therefore prepared 

 a slide on which I placed a drop of the mediuna and boiled it, and 

 when cool covered it. By the side of this I placed a second drop, 

 warming it to drive off the benzole; this I also covered. After the 

 lapse of a fortnight, I found this contained plenty of crystals, whilst 

 the adjoining drop was entirely free from them. 



" I afterwards ascertained that the second sample had been boiled 

 in water in order to extract some of its medicinal properties." 



