FENNEL. 



FERMENTATION. 



cultivated in our kitchen gardens as a garnish. 

 It is likewise used as a domestic medicine. 

 The taste and aromatic qualities of the garden 

 fennel are well known. The sweet and warm 

 seeds are a common carminative for infants. 



FENNEL, SWEET (Fceniculum dulce}. This 

 species of fennel is an annual plant, a native 

 of Italy and Portugal, where it is cultivated as 

 a pot-herb, as well as for the seeds and the oils 

 which these afford. It is a smaller plant than 

 the common fennel. The stem is somewhat 

 compressed at the base. The fruit is much 

 longer than that of the common fennel, being 

 nearly five lines long, less compressed, some- 

 what curved and paler, with a greenish tinge. 

 The turions are also sweeter and less aromatic, 

 and the fruit (seed") has a more agreeable odour 

 and flavour. 



The fruit is imported, and affords the oil of 

 fennel and the fennel water of the druggists. 

 Both are useful in flatulent colic ; and the latter 

 is a pleasant vehicle for administering other 

 medicines to children. 



FENUGREEK (Trigonella, Fccnumgracum). 

 Fenugreek is a species of trefoil sometimes 

 cultivated in fields for its seed ; but it yields a 

 very uncertain crop, owing to the variable na- 

 ture of the weather in England. The stem is 

 a foot high, erect, with round branched stalks, 

 trifoliate leaves, toothed ; the flowers small and 

 white ; the fruit a sessile, straight, erect, some 

 curved, acuminate, flat pod ; containing a num- 

 ber of yellowish seeds having a strong, disa- 

 greeable smell, and an unctuous, farinaceous, 

 and somewhat bitter taste. These seeds are 

 very emollient, and useful in cataplasms and 

 fomentations. 



FENUGREEK, RUSSIAN (Trigonella ru- 

 thenica). A hardy perennial native of Siberia, 

 blowing yellow papilionaceous blossoms in 

 July and August. It loves a strong loamy soil, 

 and an open situation. It is propagated either 

 by parting the roots in spring, or from seed. 



FERMENT (Lat./m>eo, I boil). Any sub- 

 stance employed to raise or produce fermenta- 

 tion when mixed with or applied to another. 

 Ferments are therefore either such substances 

 as are naturally present in the vegetable juice, 

 as in the grape and apple : or are added, as in 

 the manufacture of beer and bread, where 

 yeast and leaven constitute the ferment. Fer- 

 mentation is met with in fermenting liquors of 

 different kinds, as wine and beer, and the froth 

 or head thrown up by them, and its principles 

 are contained in the newly expressed saccha- 

 rine juices of various summer fruits. 



Ferments are of an albuminous and glutinous 

 character ; and the presence of nitrogen seems 

 essential in their composition. 



FERMENTATION. When certain vegeta- 

 ble substances are dissolved in water and sub- 

 jected to a temperature of 65 to 85, they un- 

 dergo a series of changes which terminate in 

 the production of alcohol or spirit; these 

 changes constitute the phenomena of vinous 

 fermentation. Sugar and some ferment are es- 

 sential to the process, and during the forma- 

 tion of the alcohol the sugar disappears, and 

 carbonic acid is more or less abundantly 

 evolved. The simplest case of fermentation is 

 that of must, or of the expressed juice of the 



grape, which, when exposed either in close or 

 open vessels to a temperature of about 70, 

 soon begins to give off carbonic acid, and to 

 become turbid and frothy; after a time a scum 

 collects upon the surface, and a sediment is de- 

 posited ; the liquor which had grown warm 

 gradually cools and clears, loses its sweet taste, 

 and is converted into wine. The chief compo- 

 nent parts of must are water, sugar, mucilage, 

 gluten, and tartar (bitartrate of potassa). Dur- 

 ing the fermentation carbonic acid escapes, the 

 sugar disappears, and with it the greater part 

 of the mucilage : the gluten chiefly forms the 

 scum and a portion of the sediment ; and the 

 tartar originally in solution is thrown down in 

 the form of a coloured deposit. Sugar and 

 water alone will not ferment; the ingredient 

 requisite to the commencement of the change 

 is the gluten, which absorbs in the first in- 

 stance a little oxygen from the air, becomes in- 

 soluble, and induces the subsequent changes. 

 The reason why grapes never ferment till the 

 juice is expressed, seems to depend upon the 

 exclusion of air by the husk or membranes. 

 In beer the alcohol is derived from the sugar 

 in the malt. When wine is exposed to air and 

 a due temperature, a second fermentation en- 

 sues, which is called the acetous fermentation, 

 and which terminates in the production of 

 vinegar. During this process oxygen is ab- 

 sorbed, and more or less carbonic acid is 

 evolved ; but the apparent cause of the forma- 

 tion of vinegar is the abstraction of hydrogen, 

 from the alcohol, so as to leave the remaining 

 elements in such proportions as to constitute 

 acetic acid. Thus alcohol is theoretically con- 

 stituted of charcoal, water and hydrogen, and 

 acetic acid of water and charcoal only ; the 

 oxygen of the air, therefore, converts the hy- 

 drogen of the alcohol into water, and so effects 

 the change into vinegar. See ALCOHOL and 

 BREWIXG. (Brande's Dirt, of Science, Ayr.) 



To illustrate these facts let us suppose that 

 the following substances are put together to 

 undergo fermentation : 300 parts sugar, 600 

 parts water, 60 yeast ; the products will be 

 771*5 parts of weak spirit, of which 171-5 is 

 alcohol of spec. grav. 0-822; 94-6 carbonic 

 acid, which flies off and carries with it 41-9 of 

 water, 12 nauseous residue, and 40 residual 

 yeast. 



Or it may be illustrated in reference to the 

 formation of the alcohol and the carbonic acid, 

 which are the only real products of vinous fer- 

 mentation, by the changes which take place in 

 the chemical components of the sugar. If we 

 take 162 parts of sugar, and 18 of water, re- 

 garding any yeast employed as merely the 

 means of commencing the fermentation, the 

 product should be 92 of alcohol and 88 of car- 

 bonic acid 



467 



