One of the most distinctive characteristics of the antiscorbutic factor is its _sensitiveness to even moderately high degrees of heat_. In this respect it differs markedly from the water-soluble or so-called "antineuritic vitamine" which withstands exposure to high temperature. The reaction of the antiscorbutic vitamine in this regard is not a simple one, and cannot be expressed by a mere statement of the degree of heat and the length of exposure. Numerous other factors, especially the reaction of the medium, but also the physical environment, must be taken into consideration--for example, cabbage is more resistant to the action of heat than its juice. An understanding of the relation of antiscorbutics to heat may perhaps best be obtained by considering the subject in connection with some definite foodstuffs. The most exhaustive study from a quantitative standpoint is that of Delf. She showed that when cabbage is subjected for an hour to a temperature of 80° to 100° C., 90 per cent. of its antiscorbutic vitamine is lost, and that 80 per cent. is lost when a temperature of 90° to 100° is maintained for twenty minutes, or a temperature of 60° for a period of sixty minutes. This experiment shows that the destructive influence of heat is enhanced to a comparatively slight degree by a rise of temperature, only about threefold when it is raised from 60° C. to the boiling point. This result points to a temperature coefficient of about 1.5 to 10° C. of temperature. It is suggested by Delf that this low coefficient of destruction is opposed to the enzyme or protein-like theory of the nature of the vitamine, and suggests a simpler constitution. On the other hand, we must bear in mind that the proteins which have been used in experiments and found to possess a high coefficient of heat, have been tested in the pure state, whereas the vitamine of the cabbage is bound up in the cell. Experiments with this vitamine as found in milk accord with the above investigation, demonstrating that intensity of heat is not as destructive as prolonged heating. This agrees with the clinical experience that milk which has been boiled for a few minutes does not induce scurvy as readily as pasteurized milk which has been heated for 45 minutes to 140° or 165° F. (Hess and Fish).