3° 



humid outside air ; and hence proper means of ventila- 

 tion should be provided. 



The completion of the curing proper is marked by the 

 development of the yellow colour. The transformation 

 from a green to a yellow colour, along with other attend- 

 ant changes, takes place while the leaf is still living 

 and if the leaf is quickly killed by heat, or by being 

 rapidly dried out, it will be impossible to remove the 

 green colour. At temperature above 125" I' the leaf is 

 rapidly killed, so that this limit must not be exceeded 

 during the yellowing process. The greatest danger in 

 the first stage of the curing, however, is that the leaf 

 will dry out so rapidly as to prematurely kill it. The 

 yellowing process may be accomplished at any tempera- 

 ture ranging between So and 120 F, provided the 

 humidity in the barn be properly managed. Care must 

 be taken to avoid drying the leaf too rapidly during the 

 first stage of the cure ; but as it begins to yellow, the 

 humidity in the barn must be materially decreased, by 

 slowly raising the temperature, and increasing the venti- 

 lation. As soon as the leaf has become yellow, the 

 whole problem is to regulate the drying so as to prevent 

 any further change in colour. This second stage of 

 curing known as "fixing the colour", is the critical 

 period and requires the closest attention. The appear- 

 ance of the yellow colour indicates that the leaf has 

 reached the dying stage, but it still contains a large 

 amount of water. When the leaf tissue dies, all the 

 moisture within the leaf is released, and will rapidly 

 move lo the surface, so that unless the moisture is 

 promptly removed, the leaf will begin to turn a reddish 

 brown colour. This is called "sponging". To avoid 

 this injury to the tobacco, the heat must be raised \ cry 



