. 474 ) 



The first step towards improvement was taken in our country 

 already in 1892 by tlie Society for the Promotion of Flax-Indrustry, 

 which tried to replace the rotting in open water by rotting in vats. 



After this metliod tlie tlax-sheaves are placed vertically and close 

 to one another in a large wooden trough, in which, at some distance 

 from the bottom, a second, perforated bottom is fitted. This false 

 bottom supports the flax and underneath the heavier rotting-water is 

 collected, which flows down from the flax after the vat has been 

 quite filled with water. 



Baron Rengers at Oenkerk, too, has tried to improve the rotting 

 of flax, by treating it after the so-called hot-waterprocess, by which 

 he seems to have obtained very satisfactory results. 



Vat-rotting and hot- waterrotting can, however, only succeed with 

 sufficient certainty, when care is taken to provide a due refreshing 

 of water; this may be done in various ways, but has not hitherto 

 been sufïiciently attended to. 



By "vat-rotting" the following advantages may be obtained. 



First. The vats can be placed in a manufactory, where the other 

 manipulations which the flax has to undergo, can also be effected. 



Second. The temperature of the rotting-water may be modified 

 at will, by which the difference between vat-rotting and hot-water 

 rotting disappears. Rotting will be possible throughout the year. 



Third. The extraction and aeration of the flax can easily be 

 regulated, so that the accumulation and multiplication of the pectose 

 bacterium is made sure, and the lactic-acid micrococci, the great 

 enemies in the rotting process, are expelled. 



The theoretical requirements for vat-rotting are in general to be 

 seen from what precedes, but it is still necessary to call attention to 

 the following points on which the success of that process depends. 



In the first place, care should be taken that the heavier water, 

 produced by the extraction of the flax, can easily be removed. By 

 the use of a false bottom the water collects underneath the flax, so 

 that it is possible first quite to fill the vat, allow it to stand for 24 

 hours, and then to drain off all the water. The flax thereby comes 

 quite equally into contact with the air, so that e^•en the densest 

 places of the sheaves are duly aerated ("decanting method"). 



It will be sufficient only once to refresh the water ^). 



1) The experiments with pure cultures of the pectose bacterium prove that 

 theoretically the refreshing of the water is not even once fully required, but pro- 

 bably the competition, particularly of the lactic-acid and butyric-acid ferments, 

 struggling to displace the pectose bacterium, will render this ideal condition unat- 

 tainable for vat-rotting on a large scale. 



