THE NITRIFYING PROCESS AND ITS SPECIFIC FERMENT. 
113 
Generation. 
Date of 
Inoculation. 
Quantity taken for Inocula¬ 
tion. 
Date when 
Nitrification 
first observed. 
I. 
9. 5.1887 
Original garden soil 
20. 5.1887 
II. 
25. 6.1887 
3 needle-loops from 
I. 
30. 6.1887 
III. 
I. 7.1887 
IT. 
7. 7.1887 
IV. 
14. 7.1887 
III. 
23. 7.1887 
V. 
25. 7.1887 
)) 
IV. 
17. 8.1887 
VI. 
26. 8.1887 
55 
V. 
1.10.1887 
VII. 
3.10.1887 
1 
55 
VI. 
7.10.1887 
VIII. 
7.10.1887 
1 needle-point from 
VII. 
17.10.1887 
IX. 
17.10 1887 
VIII. 
29.10.1887 
X. 
7.11.1887 
55 
IX. 
30.11.1887 
XI. 
1.12.1887 
5 ) 
X. 
15.12.1887 
XII. 
16.12.1887 
XI. 
13. 1.1888 
XIII. 
28. 1.1888 
XII. 
20. 2.1888 
XIV. 
29. 2.1888 
XTII. 
5. 4.1888 
XV. 
7. 4.1888 
XIV. 
27. 4.1888 
XVI. 
30. 4.1888 
XV. 
10. 5.1888 
XVII. 
12. 5.1888 
XVI. 
26. 5.1888 
XVIII. 
19. 7.1888 
XVII. 
3. 9.1888 
XIX. 
3. 9.1888 
XVIII. 
1.10.1888 
XX. 
11.10.1888 
XIX. 
20.11.1888 
XXI. 
24.11.1888 
XX. 
26. 2.1889 
XXII. 
26. 2.1889 
XXI. 
4. 5.1889 
XXIII. 
28. 6.1889 
XXII. 
18.10.1889 
XXIV. 
4.11.1889 
5 ) 
XXIII. 
17.12.1889 
Remai’ks. 
* Incubator at 30° C. 
* 
At first in incubator then 
at 15-20° C. 
15-20° C. 
In the case of those generations marked with a * plates were ponred and numerous 
bottles inoculated with isolated colonies,! but in no case could nitritication be induced. 
In the plates poured from the later generations the colonies had the appearance of 
being all of the same kind, and thus differed markedly from the plates obtained from 
the earlier generations in which there was a great variety of colonies, including 
liquefying ones which were entirely absent in the later plates. 
Not only were bottles inoculated with single colonies, hut, thinking that nitrifica¬ 
tion might be due to the combined action of two or more distinct organisms, bottles 
were sometimes inoculated with two or more different kinds of colonies from the same 
plate, and also in some cases with a large number of colonies taken from an over¬ 
crowded plate. In no single instance, however, have we succeeded in obtaining 
nitrification from a plate-cultivation, either from a single colony or from a number of 
colonies. 
In addition to the series of experiments with the line of direct generations referred 
to above, several series of collateral experiments were being simultaneously carried on. 
These collateral experiments were principally directed towards the separation and 
isolation of the nitrifying organism by the method of attenuation or dilution. 
t These bottles were maintained in some cases at 30° C., in others at 15-20° C. 
MDCCCXC.—B. 
Q 
