414 



JOURNAL OF THE DEPAtlTME^T Of* AGRiniTLtURfi. 



much space is wasted, and they often dry out too rapidly. Further- 

 more, should the atmosphere in the wilting'-room be excessively dry, 

 tlie tobacco will lose its moisture far too quickly before the desirable 

 (ha noes have taken place in the cell-contents of the leaves, and the 

 product will be sickly lookinj^'. ashy-<>Te('ii in colour; should the 

 humidity, however, be too ^reat, the lesult will be a spotted, mouldy 

 t(d)acc(). Ill order, therefore, to secure a satisfactory yellowiiio' the 

 conditions must be such that the leaves starve pTadually. It can thus 

 be seen that they must remain alive just lon.u' enouoli to allow 1he 

 necessarv chaiif^'es to take place. 



, f'^W 



[/>/n>fo h,j P. Koch. 



Fig. 3. — ^Arrangement of Tdliaccn in wilting-room. 

 First sta^e nf nuriri'?. 



As stated, ripe leaves contain a large amount of starch. This 

 starch is broken up into sugars by certain complex chemical 

 compounds known as enzymes. Small quantities of enzymes can 

 produce very extensive chemical changes without themselves suffering 

 alteration in the process. The resultant sugars form the principal 

 sustenance of the harvested leaves. In the meantime the green colour 

 changes to a lemon-yellow. Diiring the period of starvation in the 

 wilting-room, which lasts three to four days, the green colouring- 

 matter or chlorophyll is changed into a colourless substance. This 

 marks the approa(diing death of the ycdlowiiig tobacco and the end 

 (if tlu' first stage (d' curing. 



