A bacteriological study of methods for the disinfection of hides infected with anthrax spores / by F.W. Tilley.

  • Tilley, Frank W.
Date:
1915
Catalogue details

Licence: In copyright

Credit: A bacteriological study of methods for the disinfection of hides infected with anthrax spores / by F.W. Tilley. Source: Wellcome Collection.

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    siders a dilute solution of mercuric chlorid sufficient for disinfection. After disinfection hides are transferred to a saturated solution of common salt, whereby, it is claimed, they will be shrunk and brought to the “wet salted’ ’ state. The dilutions recommended are mercuric chlorid, i part in 5,000, with i per cent of formic acid; and the time of exposure to the disinfectant, 24 hours. One of the first workers to investigate the Seymour-Jones process was C. W. Ponder (9, 10). He found that artificially infected pieces of hide were not disinfected in 24 hours by a solution of mercuric chlorid, 1 to 5,000, plus 1 per cent of formic acid, in 4 cases out of 10 and concluded that the effective dilution of mercuric chlorid lay between 1 to 1,000 and 1 to 5,000. In spite of these results he recommends the service use of mercuric chlorid, 1 to 5,000, plus 1 per cent of formic acid, on the ground that his tests were made more rigorous than was necessary to meet the conditions obtaining in actual routine disinfection. It is worthy of note that he made no attempt to neutralize the disinfectant before testing the results by cultures and by inoculation of animals. Moegle (7) and Schniirer (13) have also reported favorable results with the Seymour- Jones method. The investigations of Sevcik (14) controvert all these favorable results. By neutralizing the disinfectant with sodium sulphid he was able to obtain living and virulent anthrax bacilli from spores treated with very strong dilutions of mercuric chlorid and formic acid, even when the time of exposure was extended to a number of days. Judging from his published results, it would require a dilution of mercuric chlorid, 1 to * ' ► 500, plus 1 per cent of formic acid, to destroy anthrax spores in 24 hours. The use of sodium sulphid in this manner does not seem unreasonable, since, as a matter of fact, many tanners use this substance for dehairing hides. Hilgermann and Marmann (4) have obtained similar results with the Seymour-Jones method, using ammonium sulphid as a neutralizing agent. Another method for the disinfection of hides which has recently come into prominence is the method of Prof. Schattenfroh (12), which depends upon the use of hydrochloric acid and sodium chlorid. The amounts recommended for use at room temperature are 2 per cent of the acid and 10 per cent of the salt, with a 48-hour exposure. At higher tem¬ peratures weaker dilutions may be employed. Gegenbauer and Reichel (3) have carried on an extensive research with this method and report entirely favorable results. They state that they consider the Seymour-Jones method inefficient on account of the low concentration of mercuric chlorid and also object to its use because of the discoloration by mercuric sulphid when sodium sulphid is used for dehairing. Their statements regarding the Seymour-Jones method appear to be based upon experimental work not yet published. The favorable results obtained by Gegenbauer and Reichel with the Schatten¬ froh method are confirmed by the favorable results obtained by Hilger-