TESTING THE BURNING QUALITY OF TOBACCO. 39 



rolled quite tightly, first on the form and then on the glass. At the 

 beginning of the process of rolling, the extreme outer corner of the 

 base of the wrapper is attached to the overlapping portion with a bit 

 of cigar paste, and at the end of the operation the tip of the wrapper 

 is attached to the receiver by the same means. A number of samples 

 to be tested are thus wrapped on the forms and set aside until they 

 have dried out properly. The plug in the end of the form is then 

 withdrawn and the rubber band causes the walls of the latter to col- 

 lapse, so that it can be easily withdrawn from the receiver. This 

 leaves the sample of wrapper secureh^ attached to the glass tube, 

 and in exactly the same form it would have on a cigar. The tube 

 carrj'ing the sample to be tested is connected with the remainder of 

 the apparatus, shown in figure c,, the construction of which will be 

 understood without farther explanation. The current of air is fur- 

 nished b}^ means of an ordinary filter pump, and its rate can be con- 

 trolled wnth sufiicient accuracy by measuring the flow of water through 

 the pump. The end of the wrapper is ignited with a flat gas flame, 

 and the evenness of the burn and the portion consumed before it ceases 

 to glow are carefully noted. Our method of recording the results is 

 to grade each sample on a scale of ten, both with reference to the 

 evenness of the burn and the fire-holding capacity. Of course, stand- 

 ards in these tests are purely arbitrary, as the results are onh^ intended 

 to be comparative. Under the conditions laid down for the experi- 

 ment, wrappers having markedly good burning qualities will burn up 

 completely and evenly with only one lighting, and these are given a 

 grade of 10. 



For the purpose of comparing the results obtained b}^ this method 

 with those giA^en b}" the cigar test with reference to the evenness of the 

 burn, a number of leaves were selected from diflerent types of wrap- 

 per tobacco. One half of each leaf was used fcr wrapping a cigar and 

 the second half was wrapped on the form for testing, as has just been 

 described. There was a decided lack of agreement in the results 

 obtained b}^ the two methods when only one tj^pe of filler was used in 

 making the cigars. It was found that frequently a wrapper that 

 graded only 5 or 6 on a scale of 10 in what may be called the " form 

 test " would burn quite evenly on the cigar, whereas another wrapper 

 grading as high as 9 in this test would show an uneven burn on the 

 cigar. A good illustration of this pomt is found in a wrapper which 

 was scored 10, 9, 10, respectively, in three experiments with the form 

 test and gave a fire-holding capacity" of 65 seconds by the old method 

 of Nessler. On one tj^pe of filler this wrapper gave a very uneven 

 burn, but when smoked on a lighter filler the burn was perfecth^ satis- 

 factory. These results, then, seem to emphasize the fact that, although 

 the final judgment as to the burning qualities of a wrapper which has 

 shoAvn up well in the preliminary tests must be based on the smoking. 



