N Subcutaneous Tuberculin Test. 581 



access into the circulation and, together with the pyretic action of the tuberculin, 

 bring about the general elevation of temperature. As a result of injecting tuberculin, 

 antibodies develop in the blood and when further injections of tuberculin are made 

 these antibodies neutralize its effect before it can, reach the tuberculous foci and 

 thus no reaction takes place. In very recent cases large quantities of antituberculin 

 are present in tuberculous foci, but in old lesions where the cells are completely 

 destroyed or caseated antituberculin can no longer be formed even though tuberculin 

 is present, hence the absence of reaction in such cases. According to this theory 

 then, reaction is the result of the attraction of tuberculin by its antibody into 

 the diseased centers and the concentration of the tissue-destroying forces of the 

 body at these points. Immunity to the action of tuberculin injections results 

 from the production of antibodies following the first injection which then prevent 

 later injections from reaching the diseased foci before the tuberculin is neutralized. 

 Weil and Nakayama as well as Dieterlen also demonstrated antituberculin 

 in tuberculous organs while, on the other hand Morgenroth and Eabinowitsch 

 failed in their researches to find either antituberculin or any other specific antibody 

 in the serum or tissues of tuberculous animals. Moussu showed that cattle that 

 received intraperitoneal injections of cultures of tubercle bacilli filtered through 

 porcelain tubes, also reacted when treated with tuberculin, thus proving that the 

 reaction is due to the products of metabolism of the bacilli and not to the bacilli 

 themselves. 



' According to Eber's view the increased physiological activity of the cells 

 causes tuberculin to produce tubereulopyrin and under the action of the resulting 

 pyretic condition of the body the autotuberculin already present in the body of 

 the tuberculous animal produces additional quantities of tubereulopyrin. According 

 to Marmorek tuberculin stimulates the bacilli in the body to the production of 

 toxins which, passing into the circulating fluids of the body, cause the resulting 

 fever. And since the bodies of animals with extensive foci of infection already 

 contain these toxins in large quantities a slight additional amount has no appreciable 

 effect and hence no reaction follows. According to Behring the active principle of 

 tuberculin consists in tuberculinic acid (a combination of phosphorus free protamine 

 and phosphoric nucleic acid) the effect of which, on guinea pigs is 100 times as 

 violent as that of tuberculin. Arloing and Bancel found that the injection of 

 serum from a tuberculous cow or the expressed juice of large masses of tubercles 

 did not produce reactions in tuberculous cattle, goats, dogs or guinea pigs. 



Technic of the Subcutaneous Tuberculin Test. Tuberculin used for diagnostic 

 purposes is usually diluted with nine parts by weight of a 5% solution of carbolic 

 acid. The ordinary dose of common tuberculin (tuberculin A) is as follows: Adult 

 cattle, 0.30 to 0.50 gm. according to size, yearlings 0.20 gm., calves under six 

 months 0.10 gm., the doses for horses are the same as those given for cattle; goats 

 and sheep, 0.02 to 0.03 gm.; swine, 0.05 to 0.10 gm.; dogs, 0.05 gm. The fluid is 

 preferably injected at the side of the neck into the subcutaneous connective tissue 

 and not into the muscles. The hair should be clipped and the skin disinfected 

 over a small area before injection is made. 



The test should be conducted in well ventilated stables that are not kept too 

 warm. The animals to be tested should be perfectly rested and under normal 

 conditions of feed, shelter and surroundings. A pre-injection temperature should 

 be ascertained immediately before injection and, if possible, twelve hours previous 

 to this time, preferably in the morning. (A more practical and reliable procedure 

 is to record at least three pre-injection temperatures at intervals of three or four 

 hours, but not less than two hours, the last pre-injection temperature to be taken 

 immediately before the tuberculin is injected. — Translator.) 



In animals affected with fever the test does not give reliable results, it is 

 therefore advisable to wait with such animals until they regain their normal con- 

 dition. It is best to make the injections late in the evening or some time during 

 the night, reactions that may occur can then be observed early the following 

 morning or some time during the day. Animals should be kept at perfect rest 

 and under accustomed conditions of feeding, stabling and watering. After injection 

 the temperature, pulse and respiration should be recorded, if posfible, every two 

 hours, but at least every three hours. Where circumstances do not permit this 

 arrangement the animals should be under observation at least from the bth to 

 the 21st hour after injection. The uninterrupted observation of the animal between 

 the 6th and 8th hours. is of special importance because muscular trembling and 

 other general symptoms usually appear at this time. Since reactions niay some- 

 times let in at an unusually late hour animals must be kept under observation 

 and have their temperature recorded after the 21st hour, if the temperature shows 

 a tendency to rise at that time unless, of course, a decided reaction has already 

 taken place. The recording of the temperatures should, m such cases, be continued 



