On the nature, action, and therapeutic value of the active principles of tuberculin : an investigation / by William Hunter.

  • Hunter, William, 1861-1937.
Date:
1891
Catalogue details

Licence: Public Domain Mark

Credit: On the nature, action, and therapeutic value of the active principles of tuberculin : an investigation / by William Hunter. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    to speak. I shall, for convenience sake, continue to designate them in the same way (by letters) as I have done throughout. Modification A. 1. This contained the total precipitate thrown down from tuberculin by the action of absolute alcohol. It was prepared by adding tuberculin to absolute alcohol (specific gravity, -795) in the proportion of 1 cubic centimetre of tuberculin to 10 cubic centimetres of alcohol. As regards the composition of this precipitate, I found that its solutions contained every constituent of tuberculin itself: albumoses, mucin, glycerine, colouring matter and salts. The proportion of these substances present were, however, altered, albumoses being relatively increased, the salts relatively diminished in amount. I estimated that about nine-tenths of the albumoses in tuberculin were contained in it. The albumoses were thus, even more than in tuber- culin itself, its chief constituent. I found it impossible to free them from the other substances present by repeated precipitation with absolute alcohol. Traces of glycerine, colouring matter, salts still adhered. If, however, weaker solutions of alcohol were employed, for example, 80, 70, 60, or 50 per cent., an increasing proportion of these im- purities passed into the filtrate, along with, however, a correspondingly larger and increasing proportion of the albumoses. Fifty per cent, alcohol threw down, in fact, a very small proportion of the albumoses present. Solution A2.—I found that this purification could for all practical purposes be efficiently effected—that is, with least loss of albumose, and greatest removal of other sub- stances—by precipitating with 70 per cent, alcohol, the tuberculin being added to alcohol in the proportion of 1 cubic centimetre of tuberculin to 7 cubic centimetres of absolute alcohol and 2 cubic centimetres of water. The