210 ORIGIN OF MOULD. Vv. 
furnifh a thoufand feeds, and if each fpot of 
mould contains a prodigious number of heads, it 
is clear that in the courfe of years the duft fhould 
be multiplied to excefs, becaufe, from its extraor- 
dinary levity and finenefs, it may be univerfally 
diffufed. 
We have certain evidence that feeds may tie 
kept a long time without lofing the germinating 
faculty. My illuftrious friend, M. Bonnet of 
Geneva, told me a fingular fact: In 1748, corn 
was carried from Sicily to Geneva, and lodged 
in the magazines of the Republic. Some indi- 
viduals fowed part of it in a walled garden, 1771, 
Notwithftanding the length of time, it vegetated 
perfectly and nearly as thick as common to grain 
of the fame kind. The wonderful minutenefs of 
the feed of mould feems to adapt it for long pre- 
fervation ; but I have already given a convincing 
proof of the fact. 
Heat is undoubtedly one of the moft powerful 
agents in depriving feed ‘of its germinating facul- 
ty. In the traé on infufion animalcula, it has 
been feen that the number of feeds which can 
fupport the heat of boiling water is very {mall ; 
and although M, Duhamel’s fingular cafe is cited, 
where wheat germinated after experiencing 235° 
‘in a ftove, it is here proved that the feeds of 
mould are not deftroyed by a degree infinitely 
é greater, 
