205 
Given in the order of their efficacy in this respect they are as follows: 
Ferrous ferrocyanide, copper borate, cupric ferrocyanide, ammoniacal 
solution, Bordeaux mixture, cupric hydroxide, ferric chloride, and po¬ 
tassium sulphide. 
Fourth, fifth, and sixth treatments (December 14 and 23,1891 , and Jan¬ 
uary 4,1892 ).—Nothing of importance was noted in the intervals elaps¬ 
ing between these treatments. At the time of the fourth spraying the 
potassium sulphide and ferrous sulphate solutions were injuring the 
foliage so badly that it was decided to dilute them to one-half the orig¬ 
inal strength. One peculiarfact noted in connection with theBordeaux- 
sprayed plats was the entire absence of dew from such portions of the 
leaves as were covered by the preparation. It was thought that this 
might have an important bearing on the prevention of rust, as the pres¬ 
ence of dew is known to be necessary for the infection of the host in the 
case of many parasitic fungi. Further observation, however, showed 
that this point was of no importance so far as our work was concerned. 
It was only possible to make about half of the sixth treatment, as snow 
began falling soon after spraying commenced and in an hour the plants 
were completely covered. 
Seventh treatment (January 29, 1892 ).—From January I until this 
date the ground was covered with snow, making it impossible to reach 
the plants with a spray. Up to this time the most careful search had 
failed to reveal any trace of rust. The plants had made no growth 
since the spraying on January 4. With the exception of plats 44, 50., 
58, and 60, treated respectively with potassium sulphide solution, fer¬ 
ric chloride solution, sulphur, and sulphosteatite, all the preparations 
were showing more or less plainly on the foliage. The ferrous ferrocy¬ 
anide was especially prominent, while cupric ferrocyanide, Bordeaux 
mixture, and ammoniacal solution followed in this respect in the order 
named. 
Eighth, ninth, tenth, and. eleventh treatments (February 9 and 19, 
March 4 and 14,1892, respectively)—At the time of each of the foregoing 
treatments specimens were collected from each plat and careful notes 
were made on them. However, nothing worthy of recording was ob 
served. 
Twelfth treatment (March 25, 1892 ).—The weather at this time was 
quite spring-like and many of the plants were beginning to grow. The 
duplicate plats were not in as good condition as the others, probably 
on account of being planted later and not having had an opportunity 
of getting well started before winter set in. Nothing of special im¬ 
portance was noted at this time. 
Thirteenth, fourteenth, and fifteenth treatments (April 5, 16, and 26, 
1892 ).—From March 25 to April 5 the plants made a growth of from 
3 to 4 inches. Between the 5tli and 46tli the weather was quite cool, 
in consequence of which vegetation remained almost at a standstill. 
As regards the adhesiveness, wetting power, and injurious effects of 
16486—No. 3-2 
