• «The. w&y to .prove this, when once this has been discovered, is very 

 siniple.*; 'iinoje if .we \>ake and extract by a suitable solvent for this oil r 

 and cnlAfofoffit 'Answers this purpose the best, a sample of cane juice 

 Vhictfc ha^fce&i j&virted:into three parts, of which No. I, is extracted 

 'without 'any * 'previous**' treatment, No. II, after it has been boiled 

 ivithout lime, and No. Ill after it has been boiled with lime ; 

 and if we find on the evaporation of the chloroform solutions 

 from these portions, that fractions I and II, leave no aromatic 

 residue, but that fraction III does, we have proof positive that 

 the action of lime, or caustic alkali, is necessary for the production 

 of these aromatic residues. This has been the method employed in 

 these investigations. 



The considerations which led to this discovery were : — 



1. The use of alkali in enabling No. 18 yeast to produce its 

 charactristic aroma. 



2. The failure to extract any aromatic oils from untreated cane juice, 

 or from rum made entirely from such cane juice. 



3. The discovery of this essential oil in Rum made in the ordinary 

 manner. 



4. That the treatment of the juice with lime, is the only strictly 

 chemical treatment, to which the juice on the majority of estates in 

 this country is subjected. 



The odour of this essential oil may be best described by calling it the 

 essential oil of Rum, since it has a peculiar and indescribable smell of 

 rum, and, without doubt, it is to the presence in it of this oil, that rum 

 owes its characteristic aroma ; an aroma which is so utterly different to 

 that of any other spirit. It is of an oily nature, and a small quantity 

 will remain for a considerable time in a glass exposed to the air without 

 entirely losing its strength ; and I should say therefore that it is to this 

 property that rum owes its oiliness, " body" and permanency of aroma 

 which distinguishes genuine rum from any artificial imitation. After 

 having been set free by caustic alkali from its combination in a natural 

 state, it does not appear to be further acted upon by alkalis or dilute 

 H 2 SO 4 ; but strong H 2 S0 4 seems to dissolve it with formation of a 

 faint pink colour, which may be due to carbonization. It is readily 

 soluble in chloroform, alcohol, and water. If a portion of cane juice, 

 containing this oil, be filtered absolutely brilliant, the quantity of oil 

 which can be extracted does not appear to have been lessened by filtra- 

 tion. Of course, this does not dispose of the objection that it might be 

 found floating at the top, or forming a layer at the bottom of the liquid, 

 in the form of an oil insoluble and lighter or heavier than the liquid 

 with which it was associated ; but, on carefully scrutinizing the filtrate, 

 I have not been able to observe any such phenomenon. It is true that 

 if we take a sample of cane juice, heat it with lime, and then let it settle 

 and absorb air in some deep and narrow vessel, a Nessler's reagent glass 

 or test-tube for instance, that a band of darker colour may be observed 

 at the top on cooling, but this is due to oxidation, probably of glucose 

 compounds, and, on shaking the tube, the dark brown band at the top 

 mixes easily with the lower portion of the liquid. It is also true that 

 a waxy film may be observed floating on the top of such liquor, but it 

 possesses merely a wax-like aroma, and is probably palmitic acid. That 



