definite time, even when exposed to the access of air or with ordinary water added to it. He even found that if very putrid blood was largely diluted with sterilized water, so as to diffuse its microbes widely and wash them clean of their acrid products, a drop of such dilution added to pure blood might leave it unchanged for days at the temperature of the body, although a trace of the septic liquid undiluted caused intense putrefaction within twenty-four hours. Hence he was led to conclude that it was the grosser forms of septic mischief, rather than microbes in the attenuated condition in which they exist in the atmosphere, that were to be dreaded in surgical practice. He hinted to the London Medical Congress in 1881 that it might turn out possible to disregard the atmospheric dust altogether, but did not venture to practice upon the hint till 1890, when he brought forward, at the Berlin Congress, what he believed to be absolute demonstration of the harmlessness of atmospheric dust in surgical operations. "This conclusion has been justified by subsequent experience. The irritation of the wound by antiseptic irrigation and washing may therefore now be avoided, and Nature left quite undisturbed to carry out her best methods of repair, while the surgeon may conduct his operations as simply as in former days, provided always that, deeply impressed with the tremendous importance of his object, and inspiring the same conviction in all his assistants, he vigilantly maintains from first to last, with a care that, once learned, becomes instinctive, but for the want of which nothing else can compensate, the use of the simple means which will suffice to exclude from the wound the coarser forms of septic impurity."
The Iron Age in Aboriginal Art.—Prof. O. T. Mason has been led, from his studies of aboriginal art, to attach great importance to the influence on the native American mind of the iron age, which he defines in the American Anthropologist as "the conservative folk age, the middle age as distinguished from the Renaissance, which replaced the old in progressive Europe." It is almost impossible. Prof. Mason says, for one looking over a collection of Americana, "to decide positively whether he is regarding the unadulterated Western hemisphere, or mediæval Europe, or native Africa, or some happy combination of these. In the New World during four centuries, as in the Old World, the activities, the whole life, of the native people were partly such as belong to a common humanity, such as arise through a partnership and co-operation between any group of human beings and their environment, and such as came to them from foreign lands living in the iron age of Europe. . . . There is hardly a tribe on this continent that has never heard of iron; there are tribes of Americans that preserve only a vestige of native life. Even the archæologist is often in doubt regarding buried specimens. Shell heaps, mounds, caves, and cemeteries often hide iron-made products among the goodly stuff, exciting a reasonable doubt concerning the probable authorship of the works themselves."
Value of Horseless Vehicles.—In a paper in the British Association, Mr. A. R. Sennett traced the history of mechanical locomotion from the sixteenth century, when horseless vehicles were run by means of springs, touched upon the automotors of succeeding centuries, cited the instance of a light wind-propelled vehicle which made the journey between Bristol and London in the early part of this century, and led up to the self-propelled vehicles of the present day. He pointed out that horseless locomotion on the European continent was looked upon more from the point of view of sport than of adaptation to transport in commercial and industrial operations. The author predicated, however, that we should enter upon the subject in a far more serious manner. Notwithstanding the immense mileage of railroads in England (and in the United States, too, we may add), a considerable proportion of the mileage of good common roads is represented by roads connecting towns situated at a considerable distance from railway stations. Such towns and outlying stations could be far more efficiently served by judiciously organized systems of horseless road locomotives than ever could be done by the most elaborate system of light railways. Whether we took the case of the heavy and slow haulage of the farmer and the team owner, or the light and rapid delivery required by the tradesman, we should find that