hairs with which it bristles; but the excitation it produces becomes a therapeutic means whenever the skin needs a stimulant. Unfortunately, its use next to the skin may become the source of the infirmities for the cure of which it is indicated when too effeminate an education has caused us to contract the habit of wearing it too early and without sufficient reason. It may cause a grievous predisposition to colds, rheumatisms, and neuralgias, while, the habit once acquired, it can not be given up without danger. But the use of wool is precious in some countries and under some conditions of life.
Professor Brocchi, a writer well known for his investigations in malaria, attributes the good health and vigor of the ancient Romans to their habit of wearing coarse woolen clothes; when they began to disuse them, and to wear lighter goods and silks, they became less vigorous and less able to resist the morbid influence of bad air. It was first at about the time the women began to dress in notably fine tissues that the insalubrity of the Roman air began to be complained of. Dr. Balestra, in his book on the "Hygiene of the City of Rome and of the Campagna," admits that there may be some little truth in these views, although the increasing unhealthfulness of the Roman climate was chiefly explainable by the abandonment of cultivation and the physical degeneracy of the people in consequence of the general change in the manner of living. At any rate, woolen clothing has a right to be considered an excellent prophylactic in countries infected with malaria. "In the English army and navy," says Dr. Balestra, "the soldiers of garrisons in unhealthy places are obliged constantly to wear wool next to the skin, and to cover themselves with sufficient clothing, for protection against paludine fevers, dysentery, cholera, and other diseases." According to Patissier, similar measures have been found efficacious to guard the health of workmen employed on dikes, canals, and ditches, in marshy lands; while, previous to the employment of these precautions, mortality from fevers was considerable among them.
The hygienic properties of wool are due, first, to a slight roughness of the surface that excites the functions of the skin; and, secondly, to its porosity, which, as we have already explained, moderates the expenditure of caloric and prevents a too sudden cooling of the body. Dr. Balestra believes that flannel contributes to the elimination from the body of the paludine miasms, which have been absorbed by the pores, and also to rid it of the deposits that cause rheumatic affections. The hypothesis is confirmed by the singular connection that seems to exist in miasmatic regions between rheumatic and intermittent fevers. Furthermore, woolen goods arrest in their down a portion of the germs borne in by the air which thus reaches the skin filtered and purified; Dr. Balestra has proved by direct experiments in marshy regions that thick and hairy woolen garments have the filtering power that is here attributed to them. It is hardly necessary to