74 
of the plant crystals described, but great differences in their shape 
and size, many of them too, under polarized light, being very beautiful ; 
while a lesson was to be learnt by all—that they were not accidents of 
decay or disease, but part of the economy of life in the plants in 
which they were found. 
A conversation ensued, in which Drs, HALLIFAX and CORFE, and 
Messrs. GLAISYER, the PRESIDENT (Mr. MHaselwood) and Mr. 
WONFOR took part. 
Mr. HENRY LEE, having been called upon to address the meet- 
ing, said that the few remarks he had to make belonged more 
properly to the conversazione part of the proceedings ; but they would 
perhaps not consider him out of order, as this was the first time he 
had appeared before them, if he expressed his gratitude to them for 
the kindness shown him in electing him an honorary member of their 
Society. It struck him that he might be useful occasionally, as he was 
to the Society at Croydon, over which he was President, in bringing 
down microscopical objects for mounting and distribution, such as the 
skins of dog-fish, eels, &c. It might be useful, while he set some of 
them aside for this purpose, and which he should be glad to present to 
any of the members of the Society, if he mentioned, as hints to the 
younger members, for he did not profess to teach the older and 
experienced microscopists before him, how he found it best to mount 
the skins. The usual mode was to mount them as opaque objects, 
and, as the tops of the spine were brittle, to do so either in a dry cell 
or in balsam, which gave them a good opportunity of examining them 
by polarized light. This conveyed to them a splendid colour,and showed 
that vessels seemed to extend down the spine, the same as down the 
teeth of the rays and sharks, There was another method, namely, 
dissolving out the animal matter by means of liquor potassae, and well- 
washing in distilled water. By doing this the spines with their socket 
attachments were well shown ; but it should be remembered that they 
should be soaked in turpentine for some time before mounting in 
balsam, or the venation would be filled with air. He did not think 
that there was anything else he needed to state, except in reply to 
questions which, if put, he should gladly answer. The specimens 
which he had brought with him for exhibition and distribution that 
night were from the skin of the rough hound ; and from time to time 
he would bring down portions of skins of all the dog-fishes, so that the 
members of their Society might each have a perfect series in their 
cabinets. 
Ee 
