314 Proceedings of Learned Societies. 



to investigate the action of sea water on metals and alloys. It was 

 found that when placed in a limited portion of water, iron, the 

 metal now used so largely for ship-building, was attacked with the 

 greatest rapidity, but that the action of the sea water upon it is 

 materially lessened when it is coated with zinc, and that, therefore, 

 it would repay ship-builders to have the iron galvanized — particularly 

 as iron and oak timber, in contact, are prevented from exerting their 

 mutually destructive action if the metal has been previously coated 

 with zinc. As lead appears almost entirely unacted on by sea water 

 at rest, it appears possible that it might be rendered available, 

 although pure lead is far too soft to withstand the wear and tear 

 to which ships' bottoms are subjected. In investigating the action 

 of sea water on brasses of various compositions, Dr. Calvert spoke 

 very favourably of the Muntz metal, which seems to owe its dura- 

 bility to the small proportion of lead and iron that it contains. In the 

 discussion which ensued, Mr. Robinson stated that he had found an 

 alloy of lead, tin, and antimony resisted the action of sea water 

 better than any other alloy, or any pure metal that he had experi- 

 mented with. 



ENTOMOLOGICAL SOCIETY.— April 2. 



Occurrence op Insects in Snow. — Mr. Pascoe, the president, 

 stated, that when passing over the snowfield of Monte Moro, at an 

 elevation of 8000 feet, during last July, he discovered several sharply 

 defined cylindrical holes about an inch in depth, at the bottom of 

 which was either a small mass of matter resembling peat in appear- 

 ance, or, what was still more frequent, a dipterous or ichneu- 

 monideous insect. Mr. Pascoe explained their occurrence by siip- 

 posing that the insects had alighted on the snow, and having become 

 torpid, owing to the cold, had gradually sank into the snow, from 

 the radiation of heat from their own bodies. 



Recalling to mind the simple experiments of Franklin, to prove 

 the varying amount cf absorption of solar heat by patches of different 

 coloured cloths placed on snow, as measured by the depth to which 

 the cloth melted the snow below it, it appears much more probable 

 that the sinking of the insect into the snow was due to its becoming 

 warm by the absorption of heat, and the consequent melting of the 

 snow. On the other hand, the loss of heat by radiation would 

 cause the snow to become more solid and firm. 



ROYAL SOCIETY OP EDINBURGH.— April 3. 



Economic Yaltte of Pood op Soldiers. — Dr. Lyon Playfair read 

 a paper on the food of soldiers in war and peace. In this country, 

 three quarters of a pound of meat and one pound of bread are issued 

 daily to the troops, the rest of their food being furnished from their 

 own pay. On investigating the total diet of nearly five hundred 

 men, in garrison at Chatham., for twelve days, Dr. Playfair found 

 that, stated in ounces and tenths, the returns were as follows : — 



