THE MOLDS OF CIGARS AND THEIR PREVENTION. 7 



a molecular solution of hydroquinone in 100 c. c. of paste, both molds 

 appeared and throve. 



A thicker paste, containing 10 grams of gum in 250 c. c. of distilled 

 water, was made and a series of cultures prepared to which hydro- 

 quinone, thymol, and boric acid were added. Inoculation with the 

 same molds followed. Hydroquinone in permissible concentration 

 failed to suppress the organisms. Thymol in saturated solution, 1 

 c. c. and 3 c. c. per 100 c. c. of paste, suppressed them, but gave so 

 marked an odor of thymol that the use of this substance was re- 

 garded as not advisable. Boric acid, 1 c. c. to 10 c. c. of saturated 

 solution in 100 c. c. of paste, failed to suppress the organisms. 

 Indeed, both grew more luxuriantly in these cultures than in the 

 cultures containing simple paste. Cultures containing about 0.12 

 gram of dry boric acid in 100 c. c. of paste remained sterile. 



In a third series of tests, solutions of the disinfectants were used 

 instead of water in making the pastes. Solutions of hydroquinone 

 and of boric acid were used in several proportions, as follows: For 

 1 gram of dry gum 25 c. c. of solution were used, consisting, re- 

 spectively, of hydroquinone in molecular, one-half molecular, and 

 one-fourth molecular concentration and boric acid in saturated solu- 

 tion at room temperature and in one-half saturated concentration. 

 Since at 60° F. 1 part of boric acid dissolves in 26 parts by weight of 

 water, it will be seen that the stronger boric-acid solution used in- 

 stead of water in making the paste contained roughly 3.8 per cent 

 of the acid. The paste cultures when made up were decidedly stiff 

 and kept the form of small cakes in the Petri dishes. These cakes 

 were inoculated with the two molds, and the cultures containing 

 hydroquinone and the more concentrated boric- acid solution re- 

 mained sterile. The culture containing the one-half normal boric- 

 acid solution proved a more favorable medium for these molds than 

 the plain paste. 



It was rendered clear by these experiments that hydroquinone is 

 effective when a solution containing 2.7 grams in 100 c. c. of solu- 

 tion is used instead of water in making the paste. Likewise, when 

 a solution containing roughly 3.8 grams of boric acid in 100 c. c. 

 of solution is similarly used molds are suppressed. 



Tests of the adhesive quality of the pastes so prepared were made 

 and it was conclusively shown that the presence of these chemical 

 substances does not decrease the value of the paste in this particular. 



After considering which of these substances should be recom- 

 mended for general use, boric acid was chosen because it is cheaper, 

 does not undergo change in the paste, is more readily obtained, and 

 is not liable to injure anybody if used in excess. The disadvantages 

 of hydroquinone lie in its contrasted properties on the points enu- 

 merated. 



