Whether, with the ancients, we call sympathy this peculiar correspondence of the different parts of the body, or, with the moderns, we consider it as an unknown relation in the action of the nerves, it exists through the whole animal economy; and, were the perfection of the theory of physic our object, too much attention could not be paid to its effects. But this is not a place to enlarge on a subject of so much importance. I shall only observe, that this correspondence between the voice and the organs of generation is discovered not only in eunuchs but in other men, and even in women. In men, the voice changes at the age of puberty; and in women, a strong voice is suspected to indicate a superior propensity to love. The first sign of puberty is a kind of stiffness in the groin, which becomes more sensible in walking, or in bending the body forward. This stiffness is frequently accompanied with pungent pains in the joints, and also with a new sensation in the parts which characterize the sexes. The voice is, for some time, harsh and unequal, and afterwards it becomes more full, strong, and articulate. This change is very perceptible in boys, but less so in girls, because the sound of their voices is naturally more acute. These signs of puberty are common to both the sexes, but there are others peculiar to each; as in females, the menstrual discharge and the expansion of the breasts; and in males, the beard, and power of generating. These signs, it is true, are not alike certain. The beard, for example, does not always appear precisely at the age of puberty; and there even exist whole nations where the men have hardly any beard. There is no nation, however, in which the puberty of the female sex is not indicated by the enlargement of the breasts. Universally through the human species women arrive at puberty sooner than men. But that age is different in different countries, and seems to depend on the temperature of the climate and the quality of the food. Among people who live at their ease, and feed plentifully, children arrive at this state two or three years sooner than those in the country, and among the poorer classes of people, whose food is less nourishing and more scanty. In the southern parts of Europe, and in cities, the majority of girls attain puberty at about twelve years, and boys at fourteen; but in the regions of the north, and in country places, the former are hardly so at fourteen, or the latter at sixteen. Should it be asked why females in every climate are capable of engendering more early than men? It might be satisfactorily replied, that men are much larger and stronger, their bones more hard, their muscles more firm and compact, and therefore a longer time is required for their growth. And as it is not till after the growth is completed that the superfluity of the organic particles is dispersed into the parts of generation, females must of course arrive at maturity sooner than the males.