1914] 
DUGGAR AND COOLEY—FILMS AND TRANSPIRATION 353 
Three weeks before the experiment began the plants were 
repotted, new 5-inch pots of good quality being used, and at 
the time of the installation of the experiment the drainage holes 
in the pots were carefully corked, so that all transfer of water 
would be through the porous walls. Тһе potato plants em- 
ployed were grown in the greenhouse during the early spring, 
but on April 20, about two weeks before the test was made, they 
were placed outside, to insure hardiness. When used, the 
plants were from 25 to 45 ст. high, each plant with from about 
15 to 30 leaves. Some plants were blossoming, and tubers 
were forming. 
The experiment embraced 7 series, or lots, of 10 plants each, 
sprayed with mixtures as follows: (1) strong Bordeaux, (2) 
control, no spray, (3) weak Bordeaux, (4) lime wash, (5) lime 
sulfur, (6) strong Bordeaux and lampblack, and (7) lime wash 
and lampblack. The strong Bordeaux (designated hereafter 
Bordeaux) contained 12 grams CuSO, and 14.4 grams СаО 
per liter of water, being approximately the 5-6-50 formula of 
agricultural practise. It was made up in the usual way. The 
weak Bordeaux was one-half the strength of the stronger 
mixture. Тһе lime wash was a Са(ОН): suspension consisting 
of 60 grams of CaO per liter of water. A commercial prepara- 
tion of lime sulfur was used, and this was diluted, as usual, to 
about 1-25. The Bordeaux-lampblack and the lime-wash- 
lampblack preparations were made by rubbing into small 
quantities of the Bordeaux and lime wash 5 and 10 grams re- 
spectively of lampblack, then diluting to one liter. 
The method of selecting the plants for the different lots was 
precisely that described in the previous report, that is, selecting 
at one time 7 plants (as many as there were lots) between which 
there could be little or no choice, and distributing these at 
random, 1 to each lot until each included 10 plants. АП plants 
(except controls) were sprayed on May 5, but a rain that night, 
before protection was provided, necessitated respraying the 
following day. After spraying, the plants were placed on the 
stands and each connected with its water supply. They were 
arranged on an exposed lawn, each lot occupying a row, with 
the plants 4 feet apart. Moreover, several rows of potted pota- 
toes were arranged around the entire area in order that all 
