Change of Incidence of Small-Pox. \ 2 1 



Ordinary Meeting, March 6th, 1888. 



Professor W. C. WILLIAMSON, LL.D., F.R.S., Vice- 

 President, in the Chair. 



Mr. J. R. H. Williamson exhibited an 800-candle 

 power Edison-Swan incandescent lamp, requiring about 18 

 to 20 amperes of current at an electro-motive force of 112 

 volts or 2j4 watts per candle. Mr. Williamson explained 

 the advantages offered by these high candle-power lamps 

 over the " arc " lamps. He also exhibited a new form of 

 American frictional electrical machine for exploding dyna- 

 mite in blasting, and capable of exploding 1,000 fuses at 

 once. 



On the change of incidence of Small-Pox at different 

 ages. Part II. By R. F. Gwyther, M,A. 



(Received March 6th, 1888.) 



In communicating to the last meeting the tables showing 

 the change of incidence of death by small-pox at different 

 ages, I said that the change might possibly not be altogether 

 accounted for by our changed sanitary and other arrange- 

 ments. If this is the case, the question would only be 

 partly a question of statistics, and it appears desirable to 

 consider whether we could attribute the change entirely to 

 our changed condition without having recourse to an assumed 

 increase of the virulence of small-pox. In a paper, of which 

 I shall make a large use, I find that in 1760 it was held as 

 a medical opinion that small-pox became more fatal beyond 

 the age of 20 years. This strengthened my own opinion, 

 I 



