30 The Philippine Journal of Science 1913 



Table XX shows that for each gram of treated tobacco actually 

 smoked there was obtained from the products of combustion 

 0.00106 gram of hydrocyanic-acid gas, while in the untreated, 

 for each gram of tobacco smoked, 0.00114 gram of hydrocyanic- 

 acid gas was obtained, a difference of 0.00008 gram. This 

 indicates that hydrocyanic-acid gas fumigation does not increase 

 the normal cyanogen content of smoking tobacco. 



In the combustion of any cigar a quantity of hydrocyanic- 

 acid gas is produced. This quantity depends on a number of 

 variable factors, such as the moisture, rate of combustion, firm- 

 ness of the cigar, etc. This amount far exceeds that which 

 it is possible for a cigar to absorb during fumigation. Since 

 the simplest compounds are usually first to be destroyed by heat 

 in the presence of air, it is more than probable that any hydro- 

 cyanic-acid gas retained from the fumigations is immediately 

 converted into carbon dioxide, water, and nitrogen according^ 

 to the following reaction: 



4 HCN+50,-^4C02+2H20+2N2. 



Furthermore, experiments confirm this fact and show that 

 the hydrocyanic-acid gas actually obtained from treated cigars 

 is, on the average, less than that from untreated cigars when 

 smoked under identical conditions. Sixteen treated cigars were 

 also placed in the smoking apparatus in sets of four, and air 

 was drawn through each set for twenty minutes, and passed 

 through a solution of silver nitrate. This solution was after- 

 ward analyzed for hydrocyanic-acid gas. The results were 

 negative, thus showing that there exists in fumigated cigars 

 no free hydrocyanic-acid gas. 



In smoking treated and untreated cigars with the apparatus, 

 particular attention was given to the requisites which are of 

 importance in judging the burning qualities; these are, the uni- 

 formity of combustion, the capacity for retaining a light, and 

 the color and firmness of the ash. In no case could any dis- 

 tinction be made between the treated and untreated cigars. 

 Both held the fire well, and the ash was of the proper color 

 and in most cases retained the shape of the cigar from the time 

 of lighting until it was completely smoked. The burning quality 

 is apparently not affected by treatment. 



In judging the merits of the different cigars after the various 

 treatments it was requested of those who smoked them that 

 they note aroma, taste, and burning quality. Various lots of 

 cigars of a given number were distributed to habitual smokers 



