Incomplete fusion occurs in sieve tubes.
In the evening the milk is strained through a wire sieve and transferred to barrels.
The companion cells are cut off from the same cells as those which unite to form the sieve tube.
At an early period Wallsend was famous for its coal, but the name has now a general application to coal that does not go through a sieve with meshes five-eighths of an inch in size.
Let us imagine unit mass of solution of volume V confined in a cylinder ABC between a fixed vapour sieve B and a solid piston A A B C FIG.