374 A MANUAL OF BACTERIOLOGY 



treated with water, and centrifuged. The 'supernatant 

 liquid is carefully pipetted off and kept, while the residue is 

 again submitted to the same treatment, and the process 

 is repeated until no solid residue remains. The fluids are 

 then mixed, the solid content is estimated gravimetrically, 

 some glycerin is added, and the liquid is diluted to the 

 correct volume, so as to contain 2 mgrm. of solid matter 

 per cubic centimetre, and for use is diluted with 20 per 

 cent, sterile glycerin solution. 



Tuberculin R, according to Koch, possesses distinct 

 immunising properties, and causes neither reaction nor 

 suppuration. 



For treatment of tuberculosis in man the initial dose is 

 equivalent to not more than T O^OOO-TOWO-S (Joo m g rm - 

 of solid matter, according to the nature of the case. 

 The doses are given subcutaneously at intervals of ten 

 to fourteen days, and the treatment may be controlled 

 in the earlier stages by opsonic determinations. According 

 to Latham, tuberculin may also be given by the mouth. 

 Cases of cutaneous or localised tuberculosis, and those in 

 which the opsonic index to tubercle is moderately reduced, 

 react best. 



Tuberculin, bacillary emulsion (BE), is an emulsion of 

 the powdered bodies of tubercle bacilli in 50 per cent, 

 aqueous glycerin. The mixture is allowed to sediment 

 until all heavy particles have deposited, the milky super- 

 natant fluid is pipetted off, and standardised so as to 

 contain 5 mgrm. of solid matter per cubic centimetre. 

 The dosage is similar to that of tuberculin R. 



Behring prepared another tuberculin, tulase or TC, 

 by treating tubercle bacilli with chloral, which is stated 

 to have a marked curative action, and is better adminis- 

 tered by the mouth than by subcutaneous inoculation . By 

 giving tulase to cows, the milk is said to acquire immu- 

 nising and curative properties which are transmitted to 



