408 STRUCTURE OE THE MUCOUS MEMBRANE, 
and the precipitation of sulphur. Either compound would, 
therefore, in a similar manner act as a deodorizer and dis- 
infectant, and at the same time condense the ammoniacal 
gas, that is always given off from decomposing organic 
matters, especially from accumulations of dung and urine. 
For, although ammonia be not in itself very prejudicial or 
offensive, it nevertheless mingles with the fetid gases, and 
by its volatility becomes their carrier; they are thus diffused 
through the atmosphere, by which it is empoisoned and 
rendered productive of disease. 
We have heard that £1000 have been offered for the dis- 
covery of a successful means of neutralizing these vapours ; 
and that one firm, — Messrs. Vivian, of the Hafod works — 
has spent no less than the princely sum of £14,000 to 
obviate their deleterious effects ; and still indelible proofs of 
their influence are to be seen.] 
Extracts from British and Foreign Journals. 
ON THE STRUCTURE OE THE MUCOUS MEMBRAN E 
OE THE ALIMENTARY CANAL. 
By Erasmus Wilson, Esq., F.R.S. 
[Continued from p. 290.) 
VILLOUS MUCOUS MEMBRANE. 
The term “ villous,” derived from “villus,” meaning wool, 
coarse hair, the nap of cloth, pile of velvet, &c., and itself 
derived from “ vellus,” a fleece of wool, seems aptly applied 
to the appearance of the mucous membrane of the small in - 
testine. The nap is quite evident, particularly when the 
naked eye is aided by a magnifying lens, and the view is 
greatly assisted by immersing the membrane in water, and 
examining it in that fluid. When the mucous membrane of 
the ileum is viewed in this manner with a lens of low power, 
the fidelity of the comparison with the pile of velvet is very 
obvious, for not only is the “ nap” apparent, but the pili also 
which compose the nap ; these pili being the villi, which, by 
their abundance, constitute the villous surface. Pursuing, 
then, the idea suggested by the term “ villous,” we are led to 
its component element, which we find to be a pilous projection 
of the membrane, an enlarged papilla, a villus ; the latter 
