In operating under these conditions with brewers’ “high” yeast, say, for instance, with what is called Dutch yeast, a kind well known in distilleries, fermentation shows itself in the course of a few days, in spite of the increased temperature to which our liquid, which is hopped and slightly acid and alcoholic, has been subjected. The time required for the resumption of fermentation depends both upon the degree of temperature to which the yeast has been exposed and upon the duration of its exposure. These, however, are not the points upon which we now wish to dwell. It is of greater importance to notice that the new yeast has none of the characteristics of “high” ferment, of which Dutch yeast seems to be exclusively composed, if we do not take into account impurities which cannot be avoided in a commercial product of this nature. Other specimens of Dutch yeasts would give the same results. [Illustration: Fig. 44.] [Illustration: Fig. 45.] Figs. 44 and 45 represent this new ferment magnified to the same extent as the other ferments have generally been, that is 400/1; it will readily be seen how different its form is from that of “high” yeast, how far it is from having the spherical aspect and mode of budding characteristic of that ferment. In Fig. 45 the ferment is represented in a mass; in Fig. 44 we see the ramified groups, the cells and segments of which form, after separation, the yeast of the deposit. It thus appears to be composed of jointed branches of greater or less length, which, at the junctions of the segments, put forth similar cells or segments of a round, oval, pyriform, cylindrical, or other shape; in all its characters recalling the description of _dematium_. Moreover, the cells and segments exhibit a greater sharpness of outline, as well as a more marked transparency and refractive power than are found in the majority of ferments; but the most curious physical characteristic of this ferment is its plasticity and elasticity, if we may use those terms. It can only be made to diffuse through water with great difficulty; when shaken up in it, it sinks to the bottom quickly as a clotted sediment, and the supernatant liquid appears scarcely at all charged with globules in suspension. Again, when placed on a microscope slide and compressed by the cover-glass, it returns to its original form on removal of the pressure. It is from these considerations that we have given to it the name of _caseous ferment_.[105] Lastly, this ferment produces a beer of a peculiar kind, which cannot be confounded with other kinds of beer known in the present day. We should add that it preserves its characteristics in repeated growths, and that we have never found it reproduce ordinary “high” yeast.