X, A, 6 



Gana: Leather Industry of the Philippines 



363 



the putrefaction by extracting water from the hide, while the 

 tannins convert the hide into imputrescible leather. The work 

 of the salt is transient, while that of the tannins is permanent. 

 An experiment was performed to determine the resistance to, 

 and groAvth of, liquefying bacteria in camanchile bark infusion 

 at a temperature between 27° and 32° C. Tan infusions were 

 inoculated with tannery liquors, and subsequently a loopful 

 of each was transferred to serum and gelatin media tubes. The 

 periods of time required for liquefaction are given in Table XIV. 



Table XIV. — Effect of tan infusions on liquefying bacteria. 



Liquor tested. 



Days to liquefy. 



Serum. 



1 

 Gelatin. 



Incipient 

 liquefac- 

 tion. 



Com- 

 plete. 



Incipient 

 liquefac- 

 tion. 



Com- 

 plete. 



Fresh control infusion 





42 







Control infusion 1 day old _ , - 





23 



26 



Control infusion 3 days old -. - 







Infusion 1 day after inoculation with river water 



Do 



5 



15 



1 



8 



Infusion 3 days after inoculation with river water 



Do - 



4 



10 



10 



14 



Infusion 6 days after inoculation with river water 



Do 



5 



11 



10 



6 



6 



4 







Infusion 1 day after inoculation with native tan liquor.. 

 Do - 



4 

 5 

 3 











Infusion 8 days after inoculation with native tan liquor.. 

 Do 







10 



12 



Infusions days after inoculation with native tan liquor.. 



4 



10 



4 



10 

 3 









Do 



4 



9 











" No liquefaction in seventy-five days. 



In this experiment the gelatin tubes were more resistant to 

 the action of the liquefying bacteria than the serum tubes, thus 

 illustrating the fact which must always be borne in mind by a 

 tanner that blood remaining in the hides and skins is one of the 

 causes of speedy putrefaction. Even with fresh and strong tan 

 infusion liquefying and other bacteria will thrive and are sure 

 to do mischief provided there is enough proper food for them. 



The waste of tanning material is due almost solely to the 

 Filipino practice of chopping rather than grinding the bark. 

 As the price of camanchile bark is steadily rising and constitutes 

 an item of very large expense to the tanner, any methods for 



