A celebrated Belgian surgeon lost by tetanus ten cases of major operations before he discovered that the source of the infection was his hemostatic forceps. As soon as these were thoroughly sterilized by heat he had no further undesirable complications. If the disease can be conveyed by the instruments of a careful surgeon, how much more so by the dirty scissors of a careless midwife, etc. It is true, also, that the popular notions of the laity concerning the liability to tetanus after certain forms of injury are not ill-founded. Small, ragged wounds of the hands and feet are those which ordinarily receive little or no attention, and are among those most likely to be followed by this disease. The _toy pistol_, which, a few years ago, was such a prevalent and widely sold children’s toy, was the cause of many a small laceration of the hand, due to careless handling and the peculiar injury produced by the explosion of a small charge of fulminating powder in a paper or other cap. It was not the character of the laceration or injury thereby produced, but the fact that such injuries occurred in the dirty hands of dirty children, which were most likely to become infected, that has caused the so-called _toy-pistol tetanus_ to be raised almost to the dignity of a special form of this disease. During the month of July, 1881, in Chicago alone, there were over 60 deaths from tetanus among children who had been injured in this way by these little toys. This led to their sale being suppressed by law. =Etiology.=--Two theories have had strong advocates, one being that which would account for the disease by irritation of nerves; while the second, the humoral, would explain the disease by alterations in the blood. Each has had its most ardent defenders, but both have now completely yielded to the investigations of a few observers, among whom Kitasato and Nicolaier are the most prominent. These ardent workers were, in 1885, able to clearly establish the _parasitic_ nature of this disease, and to isolate and investigate the organisms by which it is produced. [Illustration: FIG. 17 Tetanus bacilli, showing spore formation. (Kitasato.)]