66 Journal of Agricultural Research voi. iv, no. i 



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, i to 

 5,000, plus I per cent of formic acid, in 4 cases out of 10 and concluded 

 that the effective dilution of mercuric chlorid lay between i to i ,000 and 

 I to 5,000. In spite of these results he recommends the service use of 

 mercuric chlorid, i to 5,000, plus i 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, i to 

 500, plus I 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 W'Caker 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- 



