DENATURED ALCOHOL 2 si 



burner in almost any place, is such that it would undoubtedly be pre- 

 ferred to all other fuels for all purposes if it were not for the cost. 



The presence of any denaturing agent robs it, to a greater or a less 

 extent, of some of its natural advantages. The odor of the denaturant 

 is apt to be detected either before, during or after combustion. 



Denatured alcohol has been found to dissolve some metals, notably 

 brass. Of course the solvent effect is not rapid, but yet it is constantly 

 under way and necessitates repairs to metallic lamps. The metal dis- 

 solves as a salt which is left on the wick when the more volatile alcohol 

 burns, encrusting the wick and necessitating occasional cleaning or 

 trimming. This crust interferes with the efficiency of the lamp 

 whether it be used for heating or for light. But that is not the worst 

 feature of the solution of metals in the alcohol. The small quantities 

 of metal are in part volatilized and are deposited on any object which 

 is being heated. Platinum crucibles are quickly ruined by this action 

 and this alone is sufficient to absolutely prohibit the use of denatured 

 alcohol in chemical laboratories. 



Some investigations have been made to determine which constitu- 

 ent of denatured alcohol is responsible for this solvent action. Neither 

 pure ethyl alcohol nor pure methyl alcohol nor pure pyridine, nor yet 

 pure ' benzine ' would dissolve metals. The most recent work appears 

 to fix the blame on small quantities of organic esters, formed during 

 fermentation and left in the alcohol itself, which of course is not so 

 carefully purified, if it is to be denatured, as if it were intended for 

 drinking purposes. This might appear to be a small detail, but is not, 

 for it affects the usefulness of denatured alcohol for heat, light and 

 power also. Anything corrosive in action could not be tolerated in the 

 cylinder of an engine any more than it could in contact with a pla- 

 tinum crucible in the chemical laboratory. 



The efficiency of a gas engine is the greater the greater the com- 

 pression of the charge, the mixture of gas or vapor and air, before the 

 explosion. Compression can not be carried far with gasoline, for com- 

 pression, of course, heats gases, and gasoline catches fire so easily it is 

 apt to explode prematurely, i. e., while the piston head is traveling the 

 wrong way. The fact that alcohol is less readily inflammable makes 

 it possible to compress mixtures of air and alcohol much more without 

 danger of premature ignition. Therefore a larger percentage of the 

 power in alcohol can be utilized, it is more efficient. In parallel ex- 

 periments Diesel obtained 17.6 per cent, of the power in kerosene as 

 mechanical energy, 20.5 per cent, of the power in gasoline, and 31.7 

 per cent, of the power in ethyl alcohol. Those competent to judge say 

 it will not be difficult to obtain 40 per cent, of the power in alcohol as 

 mechanical work done. But, on the other hand, there is less power in 

 alcohol than there is in the petroleum products, weight for weight, as 



VOL. lxx. — 17 



