MEMORANDA. 67 
liable to boil. I think, if the flame of the spirit lamp be 
carefully regulated snch mishaps will be almost impossible. 
I have left my table covered with slides for two hours at a 
time, and on no occasion have I found the accidents com- 
plained of. 
By changing the position of the lamp and regulating the 
flame, any degree of heat required may be obtained. — 
D. Evererr Gopparp, Bank of England. 
