between the two fermentations that we have just described?  Probably it was owing to some modification effected in the medium by the previous life of the bacteria, or to the special character of the vibrios used in impregnation.  Or, again, it might have been due to the action of the air, which, under the conditions of our second experiment, was not absolutely eliminated, since we took no precaution against its introduction at the moment of filling our flask, and this would tend to facilitate the multiplication of anaerobian vibrios, just as, under similar conditions, would have been the case if we had been dealing with a fermentation by ordinary yeast.]

Before we go any further, let us devote some attention to the vibrios of the preceding fermentations.

On May 27th, 1862, we completely filled a flask capable of holding 2.780 litres (about five pints) with the solution of lactate and phosphates. [Footnote:  In this case the liquid was composed as follows:  A saturated solution of lactate of lime, at a temperature of 25 degrees C. (77 degrees F.), was prepared, containing for every 1OO cc. (3 1/2 fl. oz.) 25.65 grammes (394 grains) of the lactate, C6 H5 O5 Ca O (new notation, C6 H10 Ca O6) This solution was rendered very clear by the addition of 1 gramme of phosphate of ammonia and subsequent filtration.  For a volume of 8 litres (14 pints) of this clear saturated solution we used (1 gramme = 15.43 grains): 

     Phosphate of ammonia. ... . ... . ... . ... 2 grammes
     Phosphate of potassium. ... . ... . ... . ... 1 gramme
     Phosphate of magnesium. ... . ... . ... . ... 1 gramme
     Sulphate of ammonia. ... . ... . ... . ... 0.5 gramme]

We refrained from impregnating it with any germs.  The liquid became turbid from a development of bacteria and then underwent butyric fermentation.  By June 9th the fermentation had become sufficiently active to enable us to collect in the course of twenty-four hours, over mercury, as in all our experiments, about 100 cc. (about 6 cubic inches) of gas.  By June 11th, judging from the volume of gas liberated in the course of twenty-four hours, the activity of the fermentation had doubled.  We examined a drop of the turbid liquid.  Here are the notes accompanying the sketch (Fig. 12) as they stand in our note-book:  “A swarm of vibrios, so active in their movements that the eye has great difficulty in following them.  They may be seen in pairs throughout the field, apparently making efforts to separate from each other.  The connection would seem to be by some invisible, gelatinous thread, which yields so far to their efforts that they succeed in breaking away from actual contact, but yet are, for a while, so far restrained that the movements of one have a visible effect on those of the other.  By and by, however, we see a complete separation effected, and each moves on its separate way with an activity greater than it ever had before.”