6 
Of more interest were the results obtained by testing the ac- — 
tion of fungicides. The substance tested was the ammonical car- — 
bonate of copper compound, and of various strengths, beginning — 
with the strongest; that is, three ounces of the carbonate of cop- 
per to one quart of ammonia. By this the spores were killed, as 
also by the half, fifth and twentieth strength. An extreme dilu- 
tion was then substituted, namely, a one per cent. strength of the © 
fungicide as used for spraying grapes, etc.; that is, one part of © 
the ordinary vineyard strength was added to ninety-nine of pure — 
water, which gave a liquid that contained so little of copper as to 
require a most delicate chemical test to detect its presence. In 
such a solution the spores would not germinate, but after several — 
days, when the spores were washed five times and placed in pure 
water, they grew slowly. In order to carry the test a step far- 
ther, slides with pit-cells were arranged, with pure water in each, — 
but into alternate ones a small bit of thoroughly polished copper — 
foil was dropped, the piece being in area equal to the lead at the — 
end of a Faber pencil. That the presence of this minute amount — 
of metallic copper should prevent the germination of the spores ; 
was surprising, and only after many trials was the fact accepted. — 
In only one case, in a score or more, was any spores with the 
copper found with tubes, and in this they had probably formed 
before the sowing was made. In no instance was there any fail- 
ure of the spores to grow in the check-cells with pure water only. — 
That there might be no chance of any oxide of copper or other sol- _ 
uble compound being present, the foil was thoroughly scoured and — 
rubbed to a bright polish. After the bit of copper was removed — 
and the water changed, the spores would sometimes germinate, 
the degree of activity depending somewhat upon the length of 
time they had been held in check. . 
If now in place of pure water in a fresh preparation a percent-_ 
age of cherry juice is added to the slide-well, the spores grow, — 
the rate depending upon the amount of stimulating fluid added. ; 
A point could doubtless be reached at which the action of the 
nourishing fluid would just equal that of the copper, and the spore — 
would remain alive and inactive indefinitely. 
While at first sight there does not seem to be any practical - 
bearing for these results, upon a further consideration it may 
