98 ESSENTIALS OF BACTERIOLOGY. 



u Tuberculin" or " Kochin," as it was variously called : old cul- 

 tures of tubercle bacilli mixed with 60 per cent, glycerine and 

 filtered through a Chamberlain-Pasteur filter, the filtrate thus 

 obtained being a dark-brown liquid, sp. gr. somewhat higher than 

 water, an odor like " beef extract," a sweetish taste, not soluble 

 in alcohol ; according to Jollas, containing 50 per cent, water, 

 and showing a strong Biuret reaction ; 1 milligramme of the 

 lymph is supposed to contain but T3 ^jj milligramme of the ac- 

 tive principle. Dixon's lymph is obtained in a very similar 

 manner, and no doubt contains the same principle. 



Dixon recommends instead of using the pure culture for 

 obtaining the lymph, the tuberculosis lung of calf, a portion of 

 which is treated with water and glycerine, and then filtered 

 through Chamberlain-Pasteur filter without pressure. 



Manner of Using Koch^s Lymph. One milligramme of the 

 Koch's lymph is injected under the skin of one suffering with 

 a tubercular process, and in a few hours to a few days, a rise of 

 temperature, tightness about the chest, and exaggerated cough- 

 ing spells take place, the symptoms varying in intensity ; 

 usually a secondary rise occurs on the following day. The 

 dose has been gradually increased until the reactions subsided, 

 and 600 milligrammes have then been borne without any reaction. 



On Lupus the process could be watched and was very char- 

 acteristic ; a peculiar redness after the first injection, and after 

 a few more injections scabs formed, and an apparent cure seemed 

 to be obtained, but relapses were common and but very few 

 authentic cures if any can now be had. 



Tuberculin is a protein, and has no action on the bacilli, but 

 seems to act on tubercular tissue, adding to the inflammation 

 and exciting phagocytosis. 



Koch believed that the tuberculosis tissue was rendered 

 necrotic by this toxic principle, making the soil unfit for the 

 bacilli which then perished or were expectorated. 



Virchow dampened the excitement and ardor by showing a 

 great diffusion of fresh miliary tubercles in the bodies of persons 

 who had died and who had been treated with the lymph. Cool, 

 careful, and untiring study and time taken together will, we 

 trust, bring a happy solution and a genuine remedy. 



Tuberculocidin. This is an albuminoid obtained from the 

 original tuberculin by precipitation with alcohol. Klebs uses 



