The Use and Misuse of Tuberculin in the Treatment of Pulmonary Tuberculosis

IN 1890 Professor Koch, who had discovered the tubercle bacillus in 1882, announced that he had discovered a remedy for tuberculosis in tuberculin, made by growing virulent tubercle bacilli in a 5 per cent. glycerol broth medium for six to eight weeks at 38°C., the mature culture being sterilised in a water bath at 100GC., evaporatedl to one-tenth of its original volume, and filtered. The filtrate, which contains about 40 per cent. of glycerol, is known as tuberculin. It is labelled as r. (human) or P.TI. (bovine), according as the bacilli usedl in its manufacture are of the human or bovine variety. At first I got my tuberculin from the German firm who made tuberculin for Koch. But after xvar broke out in 1914 this was no longer obtainable, andl I got it from Burroughs, Wellcome & (Co., and coul(ldetect no difference between theirs and that inade in Giermany. Not many of those presenlt canl rememlbcr, as 1 (o, the excitement that was caused by Koch's announcement in 1890. At first the supply of tuberculin was limited, and anyone who wanted tuberculin treatment ha(d to go to Germany for it. In 1891 wealthy patients from all over the British Isles, Belfast included, paid their doctors to accompany them to Germany. Some of these patients were so far through that they died on the outward journey, some in Germany, and some on the homeward journey. Koch hacl experimented oni guinea-pigs, anid found(that these animals, wheni injected with a lethal dose of tubercle bacilli, lived much longer than otherwise if they got injections of tuberculin. But there had not been sufficient experience showing the proper dosage and intervals, and that tuberculin should not be given to febrile patients. Altogether, the dloctors who went with patients to Germany in 1891 came back so disappointed with the results of tuberculin treatment, that