The majority of these samples were certainly abnormal in composition. Ordonneau[112] has quite recently determined by careful fractional distillation the proportions of the more important constituents of cognac brandy twenty-five years old, with the following results, the quantities being stated in grammes per hectolitre:--aldehyde, 3; ethylic acetate, 35; acetal, traces; normal propylic alcohol, 40; normal butylic alcohol, 218·6; amylic alcohol, 83·8; hexylic alcohol, 0·6; heptylic alcohol, 1·5; propionic, butyric and caproic ethers, 3; oenanthic ether, 4; amines, traces. The large proportions of normal butylic and amylic alcohols obtained are very significant. It was found that commercial alcohol, prepared from corn, potatoes and beetroot, while containing isobutylic alcohol, was entirely free from normal butylic alcohol, and the difference in flavour between genuine brandy and brandy distilled from grains would appear to be mainly due to this fact. Normal butylic alcohol is obtained when fermentation takes place under the influence of elliptical or wine yeast, whereas the iso-alcohol is the product of fermentation induced by means of beer yeast; and it was shown that, by fermenting molasses, etc., with the aid of wine yeast, a spirit was obtained which much resembled brandy in colour and flavour. _Whisky._--Whisky is the spirituous liquor prepared by distilling fermented infusions of barley, wheat, corn, and other grains. Spirits that contain over 60 per cent. of alcohol are known as “high wines,” or common spirits; those containing 90 per cent. of alcohol are often termed “cologne spirits,” the name whisky being usually given to the product of a former distillation, containing about 50 per cent. by weight of alcohol. In Great Britain, the largest amount of whisky is made in Scotland and Ireland; in the United States, the principal supply comes from the States of Illinois, Ohio, Indiana, Kentucky (Bourbon Co.), and Pennsylvania (Monongahela Co.). The grains taken differ greatly in composition. In Scotland and Ireland, malted barley (pure, or mixed with other grain) is extensively employed; in the preparation of Bourbon, partially malted corn and rye are taken, while, for Monongahela whisky, only rye (with 10 per cent. of malt) is used. The essential features of whisky-making are, first, the conversion of the starch of the grain into dextrine and glucose, which takes place in the process of _mashing_; the change being due to the action of the nitrogenous principle, _diastase_ (formed during the germination of the gain); then, the transformation of the sugar into alcohol and carbonic acid by fermentation, which is induced by the addition of yeast; and, finally, the concentration of the alcohol by distillation. The quality of whisky is much affected by the nature of the grain from which it is prepared, and by the care exercised in its manufacture, more particularly in the process of distillation.