Proceedings. CXXV 
The President drew attention to the very unusual number of 
wood pigeons frequenting the neighbourhood of Croham Hurst 
this year, attracted in all probability by the abundance of acorns. 
He exhibited specimens of the glass rope and birds’-nest sponges 
and microscopic drawings of their minute structure. 
TwENTY-SEVENTH ANNUAL SOIREE. 
The attendance at the Soirée, which was held on November 25th, 
was 523 as compared with 518 last year. A larger number 
would probably have attended, but there were several counter- 
attractions in Croydon the same evening. As it was, the Public 
Hall was well filled, and everyone seemed to have spent a 
pleasant evening. The most popular exhibition was the demon- 
stration of the Réntgen rays, conducted by Messrs. Watson & 
Sons, of High Holborn, who on this occasion used their new 
penetrator-tubes, and the largest fluorescent screen yet con- 
structed, measuring fifteen inches by twelve inches. 
Another novelty was the acetylene gas generator, exhibited 
by Messrs. Thorne & Hoddle, which also attracted considerable 
attention. Acetylene is a gas composed of carbon and hydrogen 
(CoH2).- It was first discovered by Davy in 1836. The first 
patent was taken out for its production in 1890 by Mr. T. L. 
Willson, of New York, who discovered that when a mixture of 
powdered lime and coke dust is introduced into a specially con- 
structed furnace the mixture melts down into practically pure 
calcium carbide (CaCz). When this substance is brought into 
contact with water an interchange of constituents takes place, 
the two atoms of hydrogen in water combining with two of 
carbon in the carbide to form acetylene, while the oxygen of the 
water combines with the calcium: 
CaC, + HO = CoHe + CaO. 
Acetylene when burned gives a flame of great brilliancy, emitting 
a light greater than that given by any known gas, its illuminating 
value (calculated on the consumption of five cubic feet per hour) 
being, according to Prof. Lewes, no less than 240 candles, or 
about fifteen times the value of ordinary 16-candle coal gas. 
Several fatal accidents have occurred from the use of the com- 
pressed gas, so that considerable care is required in its use. It 
has also been stated that the illuminating power diminishes on 
being kept. 
Mr. Philip Crowley exhibited a large collection of birds’ eggs, 
including the gigantic fossil one of pyornis maximus from 
Madagascar, and a series of nests, each containing the egg of 
a cuckoo, showing a great variation both in size and colour. 
Specimens of the young of Bewick’s swan from Nova Zembla 
_ were shown by Mr. Henry Pearson ; an adult female of the same 
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