abolish two-thirds of the spread of tuberculosis. It is not necessary to isolate every consumptive in order to stop the spread of the disease. All that is requisite is to prevent the bacilli in his sputum from reaching the floor or the walls, to have both the latter well lighted and aired, and, if possible, exposed to direct sunlight at some time during the day, and to see that dust from the floor is not raised in clouds by dry sweeping so as to be inhaled into the lungs or settle upon food, fingers, or clothing, and that children be not allowed to play upon such floors as may be even possibly contaminated. These precautions, combined with the five-to-one resisting power of the healthy human organism, will render the risk of transmission of the disease an exceedingly small one. To what infinitesimal proportions this risk can be reduced by intelligent and strict sanitation is illustrated by the fact, already alluded to, of the almost complete germ-freeness of the dust from walls and floors of sanitorium cottages, and by the even more convincing and conclusive practical result, that scarcely a single case is on record of the transmission of this disease to a nurse, a physician, or a servant, or other employee in an institution for its cure. There is absolutely no rational basis for this panic-stricken dread of an intelligent, cleanly consumptive, or for the cruel tendency to make him an outcast and raise the cry of the leper against him: "Unclean! Unclean!" It cannot be too strongly emphasized that consumption is transmitted _by way of the floor_; and if this relay-station be kept sterile there is little danger of its transmission by other means. Practically all that is needed to break this link is the absolute suppression of what is universally and overwhelmingly regarded as not merely an unsanitary and indecent, but a filthy, vulgar, and disgusting habit--promiscuous expectoration. There is nothing new or unnatural in this repression, this _tabu_ on expectoration. In fact, we are already provided with an instinct to back it. In every race, in every age, in every grade of civilization, the human saliva has been regarded as the most disgusting, the most dangerous and repulsive of substances, and the act of spitting as the last and deepest sign of contempt and hatred; and if directed toward an individual, the deadliest and most unbearable insult, which can be wiped out only by blood. Primitive literature and legend are full of stories of the poisonousness of human saliva and the deadliness of the human bite. It was the "bugs" in it that did it. It is most interesting to see how science has finally, thousands of years afterward, shown the substantial basis of, and gone far to justify, this instinctive horror and loathing.