In two hundred consecutive specimens of sputa examined bacteriologically, tu berele bacilli were detected in .50 per cent. In early stages of phthisis and in the acute disseminated variety, tubercle bacilli may not be present in the ex pectoration, there being as yet no break ing down in the lung. Students often fail because they prepare too few speci mens, and examine these too super ficially.
It is impossible to gauge the severity of the disease by the number of bacilli in a given specimen; but, on the other hand, if the patient's sputum be sys tematically examined at definite peri ods during the illness, the progress toward recovery will be seen to be marked by a steady diminution of the tubercle bacilli.
In the examination of serous fluids, pus, or sections of tissues, the margin of error is very great if reliance be placed on negative results. A positive result is conclusive; but this can seldom be arrived at without inoculation experi ments. Even if inoculation be resorted to, the possibility of error is not elimi nated, for the quantity of centrifugalized material inoculated into a guinea-pig is very small.
In actual practice the only bacillus which is likely to be mistaken for the tubercle bacillus is the smegma and this has recently been shown to have a wider distribution than was for merly thought. For this reason the ex amination of urine for tubercle organ isms is useless unless the water be drawn off with aseptic precautions, and unless the films be (subsequent to decoloriza tion with acid) allowed to soak in alco hol for at least thirty minutes. J. 0. Symes (Brit. Med. Jour., Feb. 23, 1901).
Patients may react to tuberculin and no evidence of tuberculosis be found at autopsy. The writer's six eases seem to demonstrate that completely healed tuberculosis may react. Cases of proved tuberculosis may not react to the max imum doses. The evidence is not conclu sive that other diseases than tuberculosis may react to tuberculin. The margin of error of the tuberculin test is consider able, and probably not less than I0 per cent. The maximum dose should be higher than 4 milligrammes, and not more than IO milligrammes. Small increasing (loses are not advisable. as the reaction
is not so likely to he distinct on account of the tolerance which may be produced. An initial dose of 3 to 5 milligrammes, followed by the maximum dose, is better. The temperature should usually be nor mal before injections are given. When the temperature is distinctly above nor mal a negative result is of no value, as these patients will frequently not re spond at all, even to large doses. It scents quite certain that the glycerin extract of tuberculin deteriorates, and a fresh bottle should frequently be opened, care being taken to keep it in a cool, dark place. The 0.5-per-cent. car bolic acid solution should be made up on the day it is used if possible. The author believes that deterioration of tu berculin is the principal factor in produc ing delayed reaction,. It cannot be said that tuberculin injections are entirely without ill effects, but their use among suitable patients is no more dangerous than the use of chloroform and ether for diagnostic purposes, and is quite as justi fiable as an early diagno,is of tubercu losis is of the greatest importance. About 40 per cent. of all female patients admitted to the hospital react to tuber culin. J. 1). Madison (Amer. Med., Dec. 20, 1902).
Number of bacilli in any specimen of sputum means little: it is common to see, in incipient cases, the microscopical field crowded, and these very cases fail to show at the time or in their quent history either clinically or physical examination, any evidence of an active process. We believe that, to some extent, this is accounted for by the ability of the germ to multiply in the retained secretions, and that, so far as number is concerned, we are oftentimes observing the saprophytic tubercle lus which has germinated and passed its life-cycle in these secretions, instead of the invading bacillus which has made an inroad upon living lung-tissue and has been cast off. And in the same way, to some extent, the well-known clinical fact that bacilli are more apt to be found in the morning sputum than that occur ring later in the day. is accounted for. BACILLUS EXTERNAL TO LIVING TIS