NON-SPORING BACILLI 281 



negative result all three areas show this slight reaction. 

 Intermediate reactions, in all degrees, are observed. 

 70 per cent of adults give a positive result, probably from 

 healed tuberculosis. 



iii. Inunction of lanolin, containing 50 per cent of 

 tuberculin (Moro's test). 



iv. Ophthalmo-tuberculin reaction (1907, Wolff-Eisner ; 

 Calmette). For this test, " old tuberculin " is treated 

 with 95 per cent alcohol, and the precipitate dissolved in 

 water, and re-precipitated and dissolved several times, 

 being finally made up to a I per cent watery solution. One 

 drop of this is instilled into the conjunctival sac and 

 allowed to spread all over it. A sharp congestion of both 

 the ocular and palpebral conjunctivas results in six to ten 

 hours in the case of a positive reaction, and passes off in 

 twenty-four to thirty-six hours. In children, half the 

 dose is used and the acme is reached sooner. In several 

 cases the results of this test have been disastrous, the 

 excessive reaction leading to destruction of tissue and 

 blindness in the eye used for the test. 



2. New Tuberculin (Koch, 1897) Was introduced to pro- 

 duce anti-bacterial immunity. It was prepared thus : baciUi 

 from young virulent cultures were ground in an agate mill, 

 washed with distilled water, and centrifugalized. The 

 clear fluid was decanted and called tuberculin-O. The 

 deposit was dried, ground, and treated as before ; and 

 this was repeated several times until all the residue went 

 into emulsion ; the resulting fluids mixed together are 

 tuberculin-R. Tuberculin-O gives no precipitate with 

 glycerin added to make a 50 per cent solution. Tuber- 

 culin-R does precipitate in 50 per cent glycerin. Tuber- 

 culin-O gives a reaction on injection more readily than 

 tuberculin-R. 



3. Bacillary Emulsion (Koch, 1901). This is a I per 

 cent emulsion of pulverized bacilli in distilled water, 

 allowed to sediment for several days, and then the super- 

 natant liquid is mixed with an equal bulk of glycerin, 

 making the whole 50 per cent, i c.c. = 5 mgr. solids. 

 It resembles a mixture of tuberculin-O and tuberculin-R. 



4. Bouillon F litre (Denys, 1905). A culture of tubercle 

 bacilh in 5 per cent glycerin broth, filtered through 



