New York AGRICULTURAL EXPERIMENT STATION. C7 
contending forms, in the period covered by the experiment, which 
in the usual period covered in the preparation of cultures by the 
farmer.” 
WERE THESE TESTS FAIR TO THE COTTON? 
In using this laboratory work as a basis for predicting what 
will happen when the cotton is used by the farmer there are two 
differences in the conditions which should not be overlooked. 
In the first place the cotton at the laboratory was handled with 
sterile instruments, placed in sterile solutions and continually 
protected from contamination. At the farm the cotton itself can 
hardly escape some contamination and will be placed in “ clean 
water ” 1? which, on the farm, is never sterile and is often abun- 
dantly supplied with germ life. The chemicals will also carry 
their quota of germs. Due to the farmer’s lack of familiarity 
with the delicate process which he is superintending, the ex- 
posure which will often occur during the two or three days of the 
culture’s growth will in itself be sufficient to markedly endanger 
the result.” 
It seems but a fair deduction that by keeping out all forms of 
germ life except that originally upon the cotton, the laboratory 
conditions have been in this respect far more favorable for the 
development of Ps. radicicola than can be reasonably hoped for 
upon the farm. 
In the second place the water used at the laboratory and upon 
the farm was not alike, that at the laboratory being distilled 
water, while that at the farm would be rain or wellwater of quite 
variable composition. An important variation lies in the con- 
tent of nitrogen." 
Distilled water had been chosen for our own laboratory work 
partly because it was the water used in all other culture media 
and more especially because it was indicated in the letters patent 
of Dr. Moore. Its use was continued in our codperative test as 
the kind of water which would be most nearly alike at all the 
laboratories. 
Experiments have repeatedly demonstrated the ability of Ps. 
radicicola to develop when this water was used in preparing the 
See Nitro-Culture Co’s direction given as footnote on page 63, 
12Note the result with the control flasks, page 79. 
®8Thorp’s Dictionary of Applied Chemistry, 3 :939—994. 
