12 The Philippiyie Jowmal of Science 1913 



flavor, or burning quality must also be kept in mind, and only 

 such substances used to kill the beetles as will not alter any of 

 its original characteristics. 



My first experiments were with repellents. Those that were 

 repugnant to the beetles were also injurious to the cigars. Fur- 

 thermore, traps for the adults were used with little better success. 

 The solution of the problem is to place the factory in such a 

 condition as to prevent the reinfestation of the treated stock 

 and to obtain and use a substance that will kill the insects in all 

 stages of development. By careful preparation of the factory 

 and installation of proper apparatus, there will be no excuse for 

 the shipment of infested stock from the Philippines and the 

 consequent loss of trade caused by these damaged goods. Car- 

 bon bisulphide, hydrocyanic-acid gas, and high and low tempera- 

 tures were experimented with and proved effective. The value 

 of the first two as insecticides has long been recognized, but ac- 

 tual demonstration, as to use and dosage together with the care 

 of the manufactured products after treatment, were deemed ad- 

 visable. 



It is popularly supposed, and frequently even by the manu- 

 facturers themselves, that the exposure of tobacco to great varia- 

 tions in temperature, to carbon bisulphide, and to hydrocyanic- 

 acid gas may impair its quality and that by the use of the latter 

 some of the cyanogens may be deposited in the cigars and make 

 them injurious to the smoker. Experiments have been carried 

 on to determine whether or not any one of the three essential 

 characters of a good cigar — aroma, taste, and burning quality — is 

 impaired by the two former treatments or whether any cyano- 

 gens are deposited in the cigars by the cyanide treatment. Qual- 

 itative and quantitative analyses of the tobacco and cigars were 

 made for cyanogens, and by use of a special apparatus treated 

 and untreated cigars were smoked and the smoke drawn through 

 a solution of silver nitrate which was analyzed quantitatively 

 for cyanogens. These experiments, which are described below, 

 show that cyanogens in treated stock are not in excess of those 

 in the untreated. Several treated and untreated cigars were also 

 smoked by different habitual smokers, and the results show that 

 the treated cigars are practically indistinguishable from the 

 untreated. 



At the factory of the Compania General de Tabacos de Filipi- 

 nas, a room (Plate III, fig. 1) was screened and freed from all 

 insects by the use of hydrocyanic-acid gas and afterwards cigars 



