It must, however, be observed, with regard to this increase of the population, firstly that it tells as a factor <p 74>of criminality only in so far as it is not neutralised, wholly or in part, by other influences, mainly social, which prevent crime or render it less grave. Secondly, it is not right merely to compare the proportional rates of increase in the population with those of crime, as was done for instance by M. Bodio, who said that in Italy, from 1873 to 1883, ``since the population had increased by 7.5 per cent., crime might have increased during the same time by 7.5 per cent., without its being fair to say that it had actually increased.'' In point of fact, as M. Rossi remarked, since in Italy, and almost all the European States, the growth of the population is due to the excess of births over deaths (for emigration is more numerous than immigration), it is evident that, when we confine our attention to short periods, the addition to the population, consisting of children under ten or twelve years, does not increase crime in an appreciable degree. The deaths, on the other hand, must be subtracted from all stages of human life, but especially from the number of those who can and do commit crimes and offences.
Now, as we cannot in this place go into detail, I must confine myself to the statement of a few characteristic facts, as illustrated by European crime. Thus we perceive the influence of the great famine of 1846-7 on crimes against property in France and Belgium; the rapid oscillations of crime in Ireland, indicating the unstable political and social conditions of the country; and the parallel movements of crime in, France and Prussia. We see, indeed, a constant diminution of crime for the period between 1860 and <p 75>1870, followed (after the statistical disturbance of the terrible year 1870-1) by a period of serious and continued increase of crime, resulting from social and economic conditions, as shown especially by the increase of vagrancy and theft since 1875.
All these general facts go to prove the close and intimate connection between crime and the aggregate of its various constituents. So that, without pursuing more detailed inquiries into certain social factors of crime, which are capable of statistical enumeration, such as the increase in the number of the police, the abundance or scarcity of corn and wine, the spread of drunkenness, family circumstances, increase of personal possessions, the facility or otherwise of the settlement of disputes, commercial and industrial crises, the rate of wages, the variation from year to year of the general conditions of existence, and so forth, coincident with the development of education, encouragements to thrift and the organisation of charity, we must now proceed to draw from these statistical data the most important conclusions of criminal sociology.
<p 76> I.
Criminal statistics show that crime increases in the aggregate, with more or less notable oscillations from year to year, rising or falling in successive waves. Thus it is evident that the level of criminality in any one year is determined by the different conditions of the physical and social environment, combined with the hereditary tendencies and occasional impulses of the individual, in obedience to a law which I have called, in analogy with chemical phenomena, the law of criminal saturation.
Just as in a given volume of water, at a given temperature, we find a solution of a fixed quantity of any chemical substance, not an atom more or less, so in a given social environment, in certain defined physical conditions of the individual, we find the commission of a fixed number of crimes.
Our ignorance of many physical and psychical laws and of innumerable conditions of fact, will prevent us from obtaining a precise view of this level of criminality. But none the less is it the necessary and inevitable result of a given physical and social environment. Statistics show us, indeed, that the variations of this environment are always attended by consequential and proportional variations of crime. In France, for instance (and the observation will be found to apply to every country which possesses an extended series of criminal statistics), the number of crimes against the person varies but little in sixty-two years. The same thing holds good for England and Belgium, because their special environment is also less variable, <p 77>by reason that hereditary dispositions and human passions cannot vary profoundly or frequently, except under the influence of exceptional disturbances of the weather, or of social conditions. In fact, the more serious variations in respect of crimes against the person in France have taken place either during political revolutions, or in years of excessive heat, or of exceptional abundance of meat, grain, and wine. This is illustrated by the exceptional increase of crime from 1849 to 1852. Minor offences against the person, on the contrary, which are more occasional, assaults and wounding, for example, vary in the main, as to their annual oscillations, with the abundance of the wine harvest, whilst in their oscillations from month to month they display a characteristic increase during the vintage periods, from June to December, notwithstanding the constant diminution of other offences and crimes against the person.
On the other hand, crimes against property, and still more offences against property, show wide oscillations on account of the variability of the special environment, which is almost always in a condition of unstable equilibrium, as in periods of scarcity, and of commercial, financial and industrial crises, and so forth, whilst they are subject also to the influence of the physical environment. Crimes and offences against property display extraordinary increases in the severest winter seasons, and diminutions in milder winters.
And this correspondence between the more general, powerful, and variable physical and social factors of <p 78>crime, as well as its more characteristic manifestations such as thefts, wounding, and indecent assaults, is so constant and so direct that, when I was studying the annual movement of criminality in France, and perceived some extraordinary oscillation in the crimes and offences, I foresaw that in the annals of the year I should find mention of an agricultural or political crisis, or an exceptional winter or summer in the records of the weather. So that with a single column of a table of criminal statistics I was able to reconstruct the historical condition of a country in its more salient features. In this way psychological experiment again confirmed the truth of the law of criminal saturation.
Not only so, but it may be added that as, in chemistry, over and above the normal saturation we find that an increased temperature of the liquid envelopes an exceptional super-saturation, so in criminal sociology, in addition to the ordinary saturation we are sometimes aware of an excess of criminal saturation, due to the exceptional conditions of the social environment.