1887.] the Adulteration of Brandy. 249 



in their alcoholic beverages all over the world, whether they ferment the 

 sap of the African palm or the milk of Caucasian mares, whether they 

 distil it from the grain that grows in the valleys of Scotland, from the^ 

 potato of the German plains, or from the noble grape on the banks of 

 the Charente in the West of France and on the hills of the Paarl in 

 our neighbourhood. It is always this ethyl-alcohol (C2 H4 O.) 

 The difference of the various products lies only in the accompanying 

 substances, and as far as the distilled spirits are concerned, only in the- 

 bouquet. 



What is the bouquet ? you will ask. It is a very variable, very 

 delicate and complicated thing, and I can name here only a few of its 

 constituents. You will remember that during the fermentation all the 

 chemical compounds, which I mentioned, are formed. Their relative 

 proportions and absolute quantities vary considerably, according to tbe^ 

 fermenting liquid and the character of the fermenting agents, the 

 yeast. Also here cleanliness is of the highest importance. The 

 purer the ferment itself, the purer is also the product. Recent 

 investigations with carefully prepared ferments (yeast) have shown 

 that it is possible to obtain almost pure alcohol, which is not accom- 

 panied by any fusel-oil at all. 



This portion of the by-products of fermentation, namely the volatile 

 ethers and acids, pass easily over during the beginning of the distilla- 

 tion ; the glycerine and the succinic acid, being not volatile, remain 

 of course in the still with the refuse- wine, and the other alcohols witli 

 a much higher boiling point than ethyl -alcohol, should equally remaiu'. 

 in the still. But they do not, just as water evaporates already much 

 below its boiling point, in fact at all temperatures and even in its 

 solid state, as ice or snow, so these alcohols are volatilized with the 

 vapours of the ethyl-alcohol and water. Their quantity in the- 

 products will of course depend on the amount that was present in the 

 original liquid and on the care bestowed upon it during the distillation,. 

 The three alcohols with a higher atomic formula than the ethyl- 

 alcohol form principally the compound which is called ** fusel-oil." 

 The fusel-oil of the wine is different from that of the grain and this 

 again from that of the potato, but they all contain these alcohols in 

 various proportions. 



It is a fact which has long been known, that fusel-oil is highly 

 injurious to health, and especially t^at of the potato has always beea 

 noted as the most objectionable one of the family, but only recent 

 experiments have shown the reason for these facts. 



