We have done several other fermentations with this organism and find the same acids produced and the same gases evolved, the results just given being fully confirmed. At the same time the amount of the acids produced and their proportions vary, that is to say, the quantity of acid from a given fermentation cannot be predicted with absolute accuracy, although the conditions under which we carried out the experiments were made as like as possible.
We give the total acids from four fermentations to show the amount of variation. I. is a symbiotic fermentation caused by organisms α and β; the remainder are fermentations by α alone.
---------------------------+---------+---------+---------+--------- Fermentation | I | II | III[180]| IV ---------------------------+---------+---------+---------+--------- Total vol. acids, grm. per | 2·4968 | 1·8651 | 0·9738 | 1·5636 1000 c.c. | | | | | | | | Mean percentage BaSO_{ 4} | 89·17 | 91·76 | 95·4 | 93·6 from Ba salts of vol. acids| | | | | | | | Lactic acid | 8·9500 | 2·4380 | 1·4737 | 2·9700 ---------------------------+---------+---------+---------+---------
COMPARISON OF ACIDS FROM FERMENTATION II. AND III.[180]
------+--------+--------+--------+--------- -- | Lactic | Formic | Acetic | Butyric ------+--------+--------+--------+--------- II. | 2·4380 | 0·5080 | 1·2083 | 0·1488 III. | 1·4737 | 0·3914 | 0·5593 | 0·0231 ------+--------+--------+--------+---------
[180] 2000 c.c. gave only about the same amount of acids as 1000 c.c. fermentations. For percentages of acids, see table, p. 281.
---------+---------+---------+------------ |Weight of|Weight of|Per Cent. of Fraction| Salts | BaSO_{ 4}| BaSO_{ 4} ---------+---------+---------+------------ I. | 0·7260 | 0·6535 | 90·01 II. | 0·8150 | 0·7410 | 90·92 III. | 2·1525 | 2·1342 | 99·15 IV. | 0·3695 | 0·3627 | 98·16 V. | 0·3530 | 0·3500 | 99·15 ---------+---------+---------+------------
CALCULATION OF BARIUM SALTS AS BARIUM BUTYRATE, ACETATE, AND FORMATE.
---------+-----------+----------+----------- -- |Ba Butyrate|Ba Acetate|Ba Formate ---------+-----------+----------+----------- I. | 0·0597 | 0·6663 | .. II. | 0·0223 | 0·7927 | .. III. | .. | 0·6662 | 1·4863 IV. | .. | 0·1469 | 0·2226 V. | .. | 0·1070 | 0·2440 +-----------+----------+----------- Totals | 0·0820 | 2·3791 | 1·9529 ---------+-----------+----------+-----------