As to crimes against persons Professor Ferri is of the opinion that the direct influence of temperature is as follows: “The increase of acts of violence to persons, which is observed in connection with higher temperatures, must be chiefly dependent upon the direct physiological effect of heat upon the human organism. For by the greater warmth the consumption of material for the production of animal heat is cut down, and hence a surplus of force is stored up capable of being used for other purposes. But this, in union with the heightened irritability of temper, may easily degenerate into that criminal activity which shows itself in acts of violence to persons. With this psychological effect of the heat, it is true, there is coupled, in the case of the poorer classes who form the majority of the population, the effect of more easily obtained and more plentiful food, but this social cause in this connection is of less importance than the direct biological influence.” [119] The first explanation of Professor Ferri is astonishing because everyone feels that the heat has a different effect upon himself than the one given. The fact that during hot weather the consumption of bodily fuel is not so great as in cold weather cannot be considered as the most important point in treating of the question of crime. Heat enervates men, weakens their organism, and is the cause of men’s doing as little as possible. It has, then, just the opposite effect to that ascribed to it. [120] More than once I have had occasion to point out that it is unjust to say that the improved food of the poorer classes in summer can be the cause of the greater criminality during that season. If this were the case the persons who are well nourished at all times would furnish the greatest number of violent criminals. Now we know that just the contrary is the case. In my opinion the explanation is to be sought in the fact that in summer people come into contact with one another more, and consequently there is more opportunity for evil doing. [121] But this in itself cannot naturally explain the increase of crimes. Watering-places, where the bourgeoisie attempt to escape from the effects of the heat, are not places where crimes against persons occur in great numbers. Yet the concentration of many people in a limited space is there very great. The degree of cultivation of the people determines the greater or less ease with which quarrels arise. And what proves that this degree need not be very high is the fact that acts of violence are very rare among the bourgeois, the greater number of whom have only a superficial culture.