37 
It will be noticed from this table that there is no direct relation 
between the commercial value of a tobacco sample and its catalase 
content. On the one hand, however, it may be said that a comparatively 
high content of soluble or /-catalase would be indicative of this tobacco 
having been subjected to a sweating at a higher temperature, since the 
ammonia developed renders some catalase soluble. Further, since a 
thorough sweat is essential for the development of aroma, a high content 
of soluble or 6-catalase would indicate an improved aroma, other things 
being equal. On the other hand, it might be inferred that a sample 
containing very little soluble, but comparatively much insoluble catalase 
(see No. 11 of the above table), has passed only through the natural 
sweat and could be improved by a subjection to sweating in bulk 
after petuning with a very diluted solution of ammonium carbonate. 
- In order to reach a reliable estimate of the extent of the transforma- 
tion of the insoluble into the soluble catalase by the sweat only leaves 
of equal age and very similar to each other should serve for compari- 
son. A cured leaf can not be compared with a sweated leaf of the 
same crop when the former happens to be a lower or sand leaf and the 
latter an upper leaf. Neither can thin, strawy leaves be compared with 
gummy leaves, since the differences between these are very great in 
regard to their enzym content. Thus, a not sweated, very thin, prob- 
ably a sand leaf, yielded in fifteen minutes by the above test 7.7 c. c. oxy- 
gen for the soluble enzym and 69 c. c. for the insoluble, while a sweated, - 
guminy leaf of the same crop yielded 147 ¢. c. and 360 ¢. ¢. oxygen, 
respectively. There can be no doubt, however, that the above tests, 
judiciously carried out, may prove of practical value in certain cases 
In order to obtain comparable results, and to eliminate the factor of 
individual differences, upper leaves which can be distinguished by their — 
heavier body were picked out of a lot of cured leaves and of a lot of 
leaves sweated in bulk, of the same crop.! After moistening them a 
little they were left over night until they became pliable, whereupon 
they were spread out and the adhering sand carefully brushed off. The 
central portions of 12 leaves were then deprived of the midrib, and 
after drying at 40° C. (104° I’.)? finely pulverized. Two grams each of 
this powder were weighed out, and the tests carried out as above men- 
tioned. The result was as follows: 
Oxygen developed in thirty minutes. 
Srreduo ud notisweaved tiller leavesy-o see cots esos chee cence coecae aomeee cere ; 158 16. 5 
Cmnedeanars weabeds tiller leaves). sacece a eacese ne hese wee ones ace wioseene ese 634 236. 0 
ETOpOLuions of the volumes) Of, Oxy 2 eONets se. <i ene sas eee sense ease 1:4 1:14.3 
1This tobacco, raised in 1899, came from the Experimental Farm of the Conn. 
Expt. Sta. in Poquonock, Conn. The curing was there supported by a careful 
application of artificial heat, and supervised by Dr. E. H. Jenkins. 
2 Tobacco kept at that amore in a drying box does not become couiptetens 
dry—still retains 4 to 5 per cent moisture. 
