278 BOTANICAL GAZETTE [ocTonER 
Tobacco. : 
DER TaBak, by C. J. Koning, treats of the commerce, manuring, cul- 
ture, anatomy, diseases, and fermentation of tobacco. Well-known facts are 
here presented in a popular manner to those interested in the culture and 
trade of tobacco. Only the contents of the chapter on the so-called fermenta- 
tion of tobacco are essentially new. This process the author ascribes to the 
action of bacteria, in accordance with the hypothesis of Suchsland, “The 
aroma of the tobacco is caused by facultative anaerobes in so far as we cat 
speak of aroma in our Dutch tobacco.” In this remark, from page 23, the 
bacteria are called “facultative anaerobes,” while on page 53 we find the 
statement that the supposed principal generator of the aroma is an obligate 
aerobe. The reviewer is sorry to differ from the views of Koning, yet he 
has examined very carefully, with very high magnifying powers, wrapper 
leaves withdrawn directly from the interior of the fermenting heaps @ 
Florida, without discovering any colonies or any coating of bacteria. The 
few isolated rods and cocci found on some square centimeters of leaf cannot 
possibly have any significance. The water content (18-25 percent.) of fer. 
menting wrapper leaves prevents not only the development of fungi, but still 
more, that of bacteria. Filler leaves are more heavily moistened, and ngs 
contain 35 per cent. of water, but even these do not show bacterial colonies 
when heated in closed vessels to 55° C., a temperature reached often by the 
heaps of fermenting tobacco leaves. Even 60° C. is often reached, and 
nevertheless the heaps will heat up again when taken apart and rebul 
afresh. This would be impossible if the Bac. Tadaci really generated the 
aroma, since this dies at 50° in thirty minutes, and at 60° in five pa 
according to Koning’s own statement. At the same temperature also : 
Diplococcus Tobaci Hollandicus, which Koning claims improves the com: 
bustibility of tobacco, also succumbs. f the 
n not a single instance has the author stated the water content ee 
tobacco when he started his bacteriological investigations. Tobacco ao 
to 60 per cent. water will no doubt readily develop bacteria, especially hers. : 
Proteus group which Koning found ; cocci also will thrive in great num a 
Should this rotting be interrupted at the right time, a change of the 
might have occurred, which may be very desirable-with Dutch ore a 
such rotting is carefully avoided by the progressive American peer 
ufacturers, by keeping the water content so low as to avoid the action ‘al 
teria. Under these conditions alone the oxydizing enzyms of the py - 
will develop their activity, and to this the changes of odor and aroma a 
teristic of superior tobacco have to be ascribed.4— OSCAR LOEW. , sual 
$KoninG, C.J.: Der Tabak, Studien iiber seine Kultur und pegs 
4to, pp. 86. Amsterdam: J. H. & G. Van Heteren. Leipzig: Wilhelm : oo 
1900. M 4 (unbound), 
* Compare Reports No. 59 and 65 of the U. S. Dept. of Agriculture. 
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