While tuberculosis is a disease of all ages, its ravages are peculiar and widespread at the beginning of life. Children contribute their fair share of the awful record of one seventh of all the deaths in the world. Certain peculiarities of tuberculous manifestations in early life, such as the special involvement of lymph glands, bones, joints and peritoneum, rather than a limitation to the lung, have made the disease an interesting and hopeful study at this time. In order to successfully treat the condition, early recognition, before much destruction of tissue has taken place, is imperative. Early diagnosis, by means of inoculation, means a successful cure in a large proportion of cases. Hump-backed children, from tuberculosis of the spine, and permanent lameness from hip-joint disease, are rapidly becoming misfortunes of the past. Not only the way in which tubercle bacilli act in various tissues, but the methods of their transmission, are now known, thanks to animal experimentation. The knowledge of its spread by meat and milk has led to careful inspection of carcasses and an improvement and cleaning up of the milk supply in large areas of country by commissions and municipalities. The whole tuberculosis crusade, in which children are so largely the beneficiaries, would have been impossible without the use of rabbits and guinea pigs. The communicability of tuberculosis has thus been proven and efficient steps taken to prevent its spread. The treatment by abundant fresh air, sunlight and forced nutrition has naturally followed a better understanding of the disease. Seaside and mountain sanitoria, that are now so successfully treating the various forms of bone and gland tuberculosis in children, are but the end products of demonstrations that started in animal experimentation. Trudeau with his series of inoculated rabbits, keeping some in the open air with full nourishment that recovered, while those that were confined and underfed died, started the ideas that have had such fruitful results. In a period of twenty years, the death rate from tuberculosis in New York was reduced approximately forty per cent., and in Boston fifty-five per cent. This means the escape of hundreds of children from death or permanent disability.
Finally, a most hopeful result of animal study has shown that tuberculosis is not inherited. Thus has been removed the hopelessness that went with such a belief as regards the child. A knowledge that this dreaded disease is usually preventable and often curable acts as a stimulus to renewed and successful efforts for its final elimination.