Page:Popular Science Monthly Volume 84.djvu/290

286 contact infection or inhalation of infected dust from the air. The infection of the saliva may then enter the system through the tonsils or the alimentary tract.

The skin of man and animals is constantly infected with many germs, some of which are responsible for boils and abscesses, erysipelas and certain diseases caused by molds or mold spores and yeasts. Dust is a factor of importance in carrying these disease germs to a place where they can invade the epidermis and bring about results which may become serious. The germs settle on the skin and await the first opportunity for multiplying at the expense of the tissues. Cleanliness is a far-reaching preventative and reduction of dust in the air promotes cleanliness.

One of the greatest benefits which will result from the increased use of horseless vehicles will be the disappearance of horses and horse stables from cities. This may not appeal to lovers of horses, but sanitary and preventive measures can not be carried out without sacrificing certain emotions. The germs and spores of lockjaw are common inhabitants of the intestinal tract of horses. Dust from dried horse manure may become the immediate cause of this dreaded and fatal disease. The spores of lockjaw germs are highly resistant and may live in the air and carry infection for months. A small amount of atmospheric dust entering a casual wound may result in serious diseasterdisaster [sic], since a considerable portion of atmospheric dust is really dried horse manure. Another much feared disease is glanders or farcy. Horses are especially susceptible to this disease which causes a discharge from the nose, frequently looked upon in the initial stages as a cold. Carelessness may result in contact with this discharge which carries the virus and by means of abrasions of the skin of the stableman, rider or veterinarian the infection may be communicated. Glanders usually terminates fatally. Cases of this nature are by no means scarce. Both lockjaw and glanders will become less frequent with the disappearance of horses from our streets.

In some states and municipalities war has been declared upon the fly. There are at least two species of flies which interest us in this consideration, namely the house fly and the stable fly. It has been recognized that flies may carry disease germs and thus become important factors in spreading infection, not to take into account the discomfort, caused by flies, to man and animals. In The American Journal of Public Health of December, 1913, is reprinted part of an article of the September number of the Department of Public Safety of Rochester, N. Y., giving some interesting figures on manure production and its relation to the fly problem.

There are 15,000 horses in the city. The average output of each horse consists of thirty pounds of manure and eight pints of urine per day. It means that the 15,000 horses deposit on the streets and in the stables of Rochester over 82,000 tons of manure annually. The total manure output of the city would