Rum. 87 



fifteen times, and butyl five times, the strength of ordinary 

 ethyl alcohol. 



5. Acetal is present in most rums to a very small 

 extent. In some no re-a6tion was found. It, as well as 

 acetaldehyde, a6ls, it is said, first as irritants on the 

 mucous membrane, and then on the nerves. 



Exa6l boiling points have been given for most of the 

 bodies enumerated above that are present in rum, but 

 that does not enable us by keeping one temperature to 

 separate one from all the rest. In a mixture of 

 bodies which are all in solution, the boiling points are, as 

 it were, blended into one another, and how much 

 one may be separated from another is fixed by 

 a definite law. Thus although acetaldehyde and 

 ethylic formate and acetate come over first in 

 greatest quantity, their presence is found in rum in 

 which the '' heads" were returned to the " low wines;" 

 and, on the other hand, although the temperature of the 

 re6lifier never approached the boiling point of " fusel oil," 

 we have the misfortune to find it in the re6lified spirit. 

 Most of the bodies enumerated give distin6live colours 

 when treated with strong clear sulphuric acid, and a very 

 good insight into the running of a still may be obtained 

 by this simple means. 



Measure out 25 c.c. of the alcohol into a small glass 

 flask, and drop in 15 c.c. strong sulphuric acid. Pure 

 alcohol when treated in this way gives no colouration, 

 but the presence of aldehyde gives the solution a brown 

 colour, and the fusel oil a dark purple. 



Tested in this way, the "heads" of a still give very 

 deep dark browns, which fall very quickly and give 

 place to a pink with a trace of blue ; which continues till 



