528 NEW JP:KSEY AGKICTLTURAL COLLKGE 



A pound or so of copper turnings, used for various experiments 

 where metallic copper is required, and kindly furnished by the Pro- 

 fessor of Physics in the College, was placed in a large glass jar and 

 covered with distilled water, a glass cap being fitted over the jar. 

 From this jar the water Avas used for spraying the six plants at inter- 

 vals of about one week, until the experiment terminated after two 

 months. 



It was observed that the long contorted strands of copper soon lost- 

 their native color and became dark in the water, but no apparent 

 taste was imparted to the liquid. Xo chemical tests were used in the 

 experiment. As the weeks passed there began to be a difference in 

 the amount of the mildew upon the two sets of plants, the untreated 

 ones becoming coated thickly with fungus. It should have been 

 added among the conditions that the whole set of twelve plants were 

 placed near the^bed where the main experiments with the mildew were 

 in progress, and there was no lack of spores for a rapid and thoi'ough 

 infection. 



At the conclusion of the experiment two average plants from each 

 of the lots of six were selected, and, after being placed in a row, with 

 the spra^'ed two in alternation with the two untreated, a photograph 

 was secured that is reproduced in the engraving (Plate XTIL), 

 with, however, much loss of the striking effect as seen in the speci- 

 mens themselves. In short the plants treated with the ''copper water"^ 

 were much less infested by the mildew, and as a consequence had 

 a more healthful appearance and produced normal blooms, while 

 the untreated plants were literally covered with the fungus, and the 

 hope for blossoms practically passed. 



The above facts are stated without any application of the theories 

 of modern chemistry to account for them. This experiment calls to 

 mind one made some years ago with the germination of spores, as 

 recorded in the report for 1891, page 289. 



The tests were with the spores of the common cherry rot (Monili-i 

 fructigena Pers.), which would genninate in two hours or less, and 

 the following is reproduced as a partial explanation of the possible 

 toxic action of the copper water when sprayed upon the phlox plants 

 that were constantly subjected to inoculating spores of its favorite 

 mildew: 



"The substance tested was the ammoniacal carbonate of copper 

 compound, and of various strengths, beginning with the strongest — 



