FOUNDATIONS EXPOSED, PERAK MUSETTM. 59 



Into a carbonate. In the Chinese method of building with dry 

 bricks the interior of a wall rapidly becomes too dry to allow of 

 the mortar setting and it remains, except for about a half to 

 three quarters of an inch from the surface, in a pulverent form. 

 The coating of plaster also has the effect of forming a filter 

 and stopping the entrance of the carbonic acid, but even here 

 only about half an inch of the outer layer sets in a satis- 

 factory way. In the interior of a thick wall like the front wall 

 of the Museum, which was eighteen inches wide, the middle 

 twelve inches was so shielded from the action of the atmosphere 

 that after the lapse of seven years the mortar was in the same 

 condition as when it was built except that it had lost its water. 

 A lump of it when placed in water fell to pieces of its own 

 accord, and the crushing pressure of it when drj was, as 

 previoiisly stated, only twenty -four pounds per square inch, 

 while that taken from the nine inch wall of the work - shop, the 

 lime of which had been converted after drying into carbonate, 

 crushed at twelve pounds per square inch. 



In both these walls the mortar below the level of the 

 ground, where it had been kept moist and where the walls 

 were not covered with plaster was as hard and in as good a 

 condition as could be wished, having set thi-oughout. 



Another point of considerable interest was that in the in- 

 terior of the walls were found several white ants' nests. The 

 insects had taken advantage of the cavities originally left between 

 the bricks by the Chinese way of brick laying, and had enlarged 

 them by carrying away the mortar, and formed holes as large as 

 a man's fist in which to build their nests. The covered passages 

 leading from the nests were all constructed of mortar instead of 

 earth as is usually the case, and the nests themselves were 

 composed of the same material. 



