292 
Journal of Agricultural Research 
Vol. XXXI, No. 3 
Table II. — Analyses of celery leaves—Healthy leaves contrasted with leaves 
affected with “early blight” (Cercospora apii) 
[Data expressed in percentage of the oven-dried celery leaves] 
Determinations 
Blighted 
Average 
Healthy 
Aver¬ 
age 
Moisture content: 
Field material_ 
79.4 
76.3 
77.8 
80.0 
80.16 
80.08 
Greenhouse_ 
/75.1 
\74.2 
73.8 
77.3 
77.0 
84.15 
84.7 
84.25 
83.15 
75.86 
84.125 
77. 75 
84.1 
84.4 
Total nitrogen, Kjeldahl- 
Gunning method 
(leaves ground)_ 
2.93 
2.92 
2. 98 
2. 943 
4.78 
4.71 
4.83 
4. 773 
Nitric nitrogen: 
Scales’s Zn-Cu couple 
method... 
. 156 
. 156 
. 1601 
.1574 
.421 
.417 
.421 
.4197 
Schulze-Tieman, no- 
f .118 
.121 
. 1195 
.3255 
.320 
.325 
.323 
gas method_ 
.118 
.1191 
Ammonia nitrogen, 
Grafe’s method_ 
| .0783 
.081 
.0769 
. 07145 
. 07693 
.06045 
.0632 
.0714 
.0632 
.06456 
Nitrogen of nitrites, 
qualitative tests 
Present-good test 
Average 
Faint trace 
Aver¬ 
age 
Total hydrolyzable “ N,” 
Kjeldahl-Gunning_ 
2.601 
4.342 
Nitrogen distribution, 
Hausmann’s method: 
Acid amide nitrogen.. 
“ Humin” nitrogen... 
Diamino acid nitro¬ 
gen___ 
0.4843 
0.4911 
0.4877575 
0.7899 
. 80725 
0.7986 
.3160 
.3091 
. 31259 
.3229 
. 30913 
.3160 
.4602 
.4533 
. 456825 
.8107 
.797 
.8038 
Monoamino acid ni¬ 
trogen__ 
1.340 
1.347 
1.3443 
2.418 
2.428 
2.4233 
Protein nitrogen, Ritt- 
hausen-Stutzer method. 
2.174 
2. 215 
2.188 
2.1923 
3.261 
3.281 
3.268 
3.27 
Nonprotein nitrogen 
“N,” in filtrate after 
precipitation with Stut- 
zer’s reagent CuOH 2 ... 
.759 
.7383 
.7383 
.7452 
1.422 
1.415 
1.415 
1. 4173 
Analyses of the Septoria apii material and the corresponding healthy 
leaves were made by different methods, for the most part, than those 
used in the spinach investigations. These methods gave results that 
were very satisfactory and for convenience of manipulation seem to 
be desirable. Brief directions for carrying out the various tests are 
included, but for complete instructions the original articles should 
be consulted. 
Methods of Analysis Used on Material Affected with Septoria apii 
In the determination of the total nitrogen the method of Davisson 
and Parsons (7) was followed. One-gram samples of the material 
were placed in 500 c. c. Kjeldahl flasks, 100 c. c. of distilled water 
added, and the suspension shaken for a short period (2 to 5 minutes). 
Two drops of kerosene, 1 gm. of Devarda’s alloy, and 1 c. c. of satu¬ 
rated sodium hydroxide solution were then added; the dissolved 
nitrates and nitrites reduced to ammonia were caught in the tower 
containing sulphuric acid (27 c. c. concentrated &cid plus 8 c. c. 
water). The complete reduction of the nitrates was assured by 
heating the solution to boiling in minimum time and then heating 
