BACILLUS TUBERCULOSIS AND ALLIED ORGANISMS 1 17 



The centrifugal machine is used either in connection with 

 Biedert's sediment method or without, to obtain the solids 

 suspended in urine or serum. 



Antiformin Method. A mixture of chlorin water and so- 

 dium hydroxid; chlorin is liberated, and this dissolves most 

 of the organisms in the sputum and the mucus, leaving un- 

 altered the tubercle bacillus. Dilute thick sputum with dis- 

 tilled water, add one-quarter volume antiformin, mix until 

 solution is effected; add alcohol, equal volume, and allow 

 mixture to stand eighteen hours. Prepare cover-slip prepa- 

 rations from this. 



Staining Bacillus Tuberculosis in Tissue (Sections). The 

 general method of Gram can be used, but the better way is 

 to use the following: 



Warm carbolfuchsin, fifteen to thirty minutes. 



5 per cent, sulphuric acid, one minute. 



Alcohol, until a light-red tinge appears. 



Weak methylene-blue, three to five minutes. 



Alcohol, for a few seconds. 



Oil of cloves, until cleared. 



Canada balsam, to mount in. 



Instead of carbolfuchsin, alcoholic solution of fuchsin or 

 anilin-water fuchsin can be used, but the sections must re- 

 main in the stain overnight. 



Hardened Sputum and Sectioning. Sputum can be hard- 

 ened by placing it in 98 per cent, alcohol. Thin sections can 

 be obtained by imbedding the hardened sputum in celloidin. 

 The sections are then stained as ordinary tissue sections. 



To Preserve Sputum. Sputum can be preserved for future 

 use by placing it in alcohol, where it can be kept for months. 

 Cover-glass preparations can then be made by softening the 

 coagula with a small amount of liquor potassa. 



Pathogenesis. When a guinea-pig has injected into its 

 peritoneal cavity some of the diluted sputum containing tu- 

 bercle bacilli, it perishes in about three weeks, and the follow- 

 ing picture presents itself at the autopsy: at the point of 

 inoculation there is a local tuberculosis little tuberculous 



