In this manner the bacteria may be said to be subjected to a succession of cold shocks, instead of being permitted to remain in a continuously benumbed condition. The vitality of typhoid bacilli was put to the test under these circumstances, the freezing process being carried on over twenty-four hours, during which time, however, it was three times interrupted by the ice being thawed. The effect on the typhoid bacteria was striking in the extreme; from there being about 40,000 present in every twenty drops, representing the number originally put into the water, there were only ninety at the end of the twenty-four hours; and after a further period of three days, during which this treatment was repeated, not a single bacillus could be found. This signal surrender to scientific tactics forms a marked contrast to the stout resistance maintained for over 103 days under the ordinary methods of attack. But, although the typhoid bacillus appears to submit and meekly succumb to this plan of campaign, yet the conclusion must not be rashly drawn that all descriptions of bacteria will be equally feeble and helpless in these circumstances. Doctors Percy Frankland and Templeman have shown that the spore form of the anthrax bacillus is able to successfully challenge all such attempts upon its vitality. Thus when put into water and frozen at a temperature of -20° C., the process being extended over a period of three months and interrupted no fewer than twenty-nine times by thawings, when examined even after this severe series of shocks, it showed no signs of submission and clung to life as tenaciously as ever. The more sensitive form of anthrax, however, the bacillus, was readily destroyed; for after one freezing its numbers were already so much reduced that it was only with difficulty that even one or two could be found, and after the second freezing every one out of the large number originally present had died. Renewed interest has been of late revived in the question of the behaviour of bacteria at low temperatures, in consequence of the possibility of obtaining, by means of liquid air and liquid hydrogen, degrees of cold which were undreamt of by the scientific philosophers of fifty years ago. Public interest has also been quickened in such inquiries on account of the important part which low temperatures play in many great commercial developments, their application rendering possible the transport from and to all parts of the world of valuable but perishable foodstuffs, thus encouraging local industries by opening up markets, and bringing prosperity to countries and communities which before were seeking in vain an outlet for their surplus produce.