426 THE WOAD AND WELD CROPS. 



fermentative process which it has to undergo is sufficiently 

 carried out. 



The presence of moisture is necessary to all fermenta- 

 tive action, which indeed is mainly controlled by its ab- 

 sence or presence in proper proportions; so that in this 

 case, beginning with a dry substance, the addition of water 

 is necessary to set up, in the first instance, the fermen- 

 tative process, while its judicious administration during 

 the subsequent periods of the operation places a power in 

 the hands of the skilful workman, which enables him very 

 materially to control the changes that take place in the 

 mass, and thus to obtain a satisfactory result in the shape 

 of superior quality of produce. It is of the utmost im- 

 portance that the fermentative action should pervade the 

 whole mass equably, and this can only be secured by fre- 

 quent and regular waterings, and by constantly keeping the 

 mass turned over and over, as not withstanding all our endea- 

 vours, the action of decomposition will be proportionately 

 more vigorous as we descend below the surface, and the only 

 way to check and regulate it is to keep shifting the lower 

 layers to the top. Considerable care and skill are required 

 in turning the mass with the shovel, so as to separate any 

 portions that are disposed to cling together, and to leave 

 each shovelful lying as light and as separate as possible. 



As the process proceeds, various gases, resulting from the 

 gradual decomposition the mass is undergoing, are gene- 

 rated ; these are indications of its progress that call into 

 play another organ of sense the nose an experienced 

 workman being able to form a very correct opinion as to 

 the state of the mass whether the fermentation was pro- 

 ceeding too fast or too slowly by the peculiar odour 

 emitted, and which, to those unaccustomed to a " woad- 

 house," is extremely offensive and injurious. If the fermen- 

 tation flags the woad is liable to become "heavy," and to 

 soil the fingers on rubbing it, which it ought not to do if 



