The tests were made in small flat-bottomed 10-cc flasks, tomato bouillon being used for the tests on moist conidia. The bouillon was used so as to have the conidia in a nutritive medium after the test was made, without transferring. The time for those at 100° C. was estimated from the time of ebullition. At the end of the specified time, the flasks were cooled promptly under running water. As the flat bottoms gave comparatively large surface, the heating and the cooling could be effected in a short time. For the tests below 100° C. a vessel of water was heated to the desired temperature, and the flasks were immersed in it and shaken constantly. The dry conidia were placed in test tubes which were immersed in boiling water for the desired time and cooled under running water, after which 10 cc of sterilized tomato bouillon was added. After determining the death point in this manner and finding it to be much lower than had been supposed, it was decided to make the test again, but using ketchup as the medium. Ten grams of ketchup were sterilized, then inoculated from a vigorous growth of mold, and tested with a set in which the tomato bouillon was used. For those below 100° C. the two flasks which were to receive the same temperature were held in the vessel of water at the same time, so that as nearly as possible the treatment would be identical. The following results were obtained: _Thermal death point of moist and dry conidia of Penicillium._ PENICILLIUM IN 10 CC OF TOMATO BOUILLON. -----------+------------+----------+------------+--------------------- No. of |Temperature.| Time of |Time before |Period of observation experiment.| | heating. |germination.| and developments. -----------+------------+----------+------------+--------------------- | _°C._ |_Minutes._| _Days._ | 1 | 85 | ½ | 3 |Dark strings from | | | |spores; 9 days; | | | |no development. 2 | 80 | 1 | | 3 | 75 | 1 | | 4 | 70 | 5 | | 5 | 65 | 5 | 3 |Dark strings running | | | |from spores; 9 days; | | | |growth normal, spots | | | |on surface. 6 | 60 | 5 | 3 | Do. 7 | 55 | 5 | 3 | Do. -----------+------------+----------+------------+---------------------