Proceedings of Learned Societies. 239 



nical characters. The milkiness or opacity of the latex may be due 

 to equal sized particles of extreme minuteness, like the molecular base 

 of the chyle of mammalia ; or to larger, unequal sized, oil-like 

 globules. There may also be starch-cells in the juice, as in Euphor- 

 biacece. The limpid fluid in which the microscopic objects of the 

 milky juice swim he calls Liquor Laticis. It is spontaneously coagu- 

 lable at the temperature of the air, and is remarkably coagulated 

 by water. The whole subject is one that may be easily examined by 

 micrographers in the country, and the season is approaching for this 

 interesting pursuit. 



CHEMICAL SOCIETY.— March 1. 



Destruction of Oak Timber in Sea Water by contact with 

 Iron. — Mr. Crace Calvert called attention to the destructive action 

 of iron plates and bolts on oak timber when submerged in sea 

 water ; the oak at the point of contact becomes dark in colour, 

 softened , and partially disorganized. This change appears to be 

 dependent on the presence of tannin, as teak and mahogany are not 

 affected in the same manner as oak. The probable result of the 

 action will be, that ships of oak plated with iron, after the manner 

 of the " Warrior" and other vessels recently constructed, will become 

 unserviceable in the course of a very few years. It is found that if 

 the iron is protected by a coating of zinc — or, as it is termed, is 

 galvanized — the action is prevented, and the oak timber does not 

 change in colour or solidity. This mode of protection is even appli- 

 cable to the iron bolts used in ship-building, as it is found that so 

 close and complete is the adhesion of the two metals, that the zinc 

 is not stripped off when the bolts are driven into the timber. 



ETHNOLOGICAL SOCIETY. —Mar oh 4 



On the Shell Mounds of the Malay Peninsula. — Mr. G-. W. 

 Earl described the singular shell mounds existing in the province 

 of Wellesley, near the Mudah River. They are about five or six 

 miles from the sea, being situated on sand ridges that appeared 

 formerly to bound the narrow estuaries communicating with the 

 ocean. The mounds, which are entirely composed of cockle-sbells, are 

 about 18 to 20 feet in height, and recently have been largely em- 

 ployed by the Chinese immigrants as a source of lime. The anti- 

 quity of the mounds must be very great, as shown by the fact that 

 the shells were partly cemented together by crystallized carbonate 

 of lime, the result of the very slow action of atmospheric and 

 aqueous influences. At the bottom of one mound, which contained 

 20,000 tons of shells, a human pelvis was found, and other remains 

 and stone implements have been obtained from the Chinese lime- 

 burners. The formation of these mounds was attributed by Mr. Earl 

 to the Semangs, who are described as a diminutive negro race that 

 are now sparsely scattered over the surrounding country, but who 

 were evidently very numerous and widely spread formerly. 



