726 Tuberculosis 



The suggestion of A. E. Wright that the administration of all such 

 products should be controlled by an examination of the opsonic 

 power of the blood, the remedy being withheld if this was high and 

 applied if low, the utmost care being taken not to prolong the "nega- 

 tive phase," seemed to be an excellent one, affording the beginning of 

 a scientific method of studying the disease, but unfortunately it 

 seems not to have been successful in practice, and the tedium and 

 expense of the examinations makes them impracticable. 



Agglutination.— Arloing* and Courmontf found it possible to 

 prepare homogenized cultures of the tubercle bacillus, and saw them 

 agglutinated by the serum of immunized animals and by the serum 

 of tuberculous patients. The subject was investigated by Koch, J 

 who carefully reviewed the details of technic and investigated the 

 method, which, he concluded, was valueless for the diagnosis of 

 human infection, though a good guide to the extent of immunization 

 achieved by the therapeutic administration of tuberculin-R. Thel- 

 ling§ has also shown the reaction to be too irregular to be of practical 

 diagnostic importance. 



The technic of the agglutination test as given by Koch]| is as 

 follows : 



Any culture of the tubercle bacillus can be made useful by the following treat- 

 ment: Collect the bacillary masses upon a filter-paper and press between layers 

 of filter-paper to remove the fluid. Weigh out, say, 0.2 gm. of the solid mass and 

 rub it in an agate mortar, adding, drop by drop, a J^o normal sodium hydroxid 

 solution until the proportion of i part of the culture to 100 parts of the solution is 

 reached. 



It is necessary that the rubbing be thorough in order that the firm connection 

 between the bacilli shall be broken up and the organisms distributed throughout 

 the fluid. The operation usually lasts fifteen minutes. The fluid is then placed 

 in a hand centrifuge and whirled for six minutes, then pipetted off, and rendered 

 feebly alkaline by adding diluted hydrochloric acid solution. The fluid thus 

 obtained is too concentrated to be used in this form, so must be diluted with 0.5 

 per cent, carbolic acid in 0.85 per cent, sodium chlorid solution. This solution 

 shoidd be repeatedly filtered before receiving the bacillary suspension. The 

 quantity of bacillary suspension to be added should make the final product a 3000 

 dilution of the original. It should look like water by transmitted light, but 

 slightly opalescent by reflected light. 



The serum to be tested is added in proportions of i : 10, 1 125, i : 50, i : 75, i : 100 

 I : 200, I : 300, etc., and is to stand for twenty-four hours. By inclining the tube 

 and looking through a thin stratum of the fluid the agglutinations can be at once 

 detected. 



Complement-fixation. — The complement-fixation test of Bordet 

 and Gengou was first applied to the study of the tubercle bacillus 

 by Wassermann and Bruch** and investigated by a long line of 

 clinicians and laboratory workers. It has, however, been abandoned 



*" Congress de m6d. int. Montpellier," 1898; " Compt.- rendu Acad, de 

 Sciences de Paris," 1898, T. cxxvi, pp. 1319-1321. 



t "Compt. rend. Soc. de Biol, de Paris," 1898, No. 28, v; "Congr. pour 

 I'etude de la Tuberculose," Paris, 1898. 



t "Deutsche med. Wochenschrift," 1901, No. 48, p. 829. 



§ Loc. cit. 



|[ "Deutsche med. Wochenschrift, " 1901, No. 48, p. 829. 

 ** "Deutsch med. Wochenschrift," igo6, p. 449. 



