Elements of human physiology / by Henry Power.

  • Henry Power
Date:
1885
Catalogue details

Licence: Public Domain Mark

Credit: Elements of human physiology / by Henry Power. Source: Wellcome Collection.

    35/536 (page 13)
    Chap. I.] Ferments and Fermentation._ soluble salt. The three principal fats of the human body are tristearin, tripalmitin, and triolein. The following formulae represent, according to Gamgee, the composition of these bodies: ( Palmitin, C3H5(OCi6H3iO)3 Olycerin C3H5(OH)3 \ Stearin, C3H5(OCi8H350)3 ( Olein, C8H5(OCi8H330)3 Palmitic acid, CieHsjOjOH Stearic acid, CisHsgOjOH Oleic acid, CisHasOjOH. Stearin melts at about 60*^ 0., palmitin at about 45*^ C, olein at about 30° 0. Stellate crystals of stearin and palmitin often occur in fat cells. Ferments and fermentation.—The pheno- mena of fermentation are so remarkable that they have at all times attracted attention. From a remote period of antiquity, and in every nation that has emerged from barbarism, it has been recognised that the heavy and indigestible mass resulting from the mixture of flour with water can be rendered light and spongy by the admixture of a small quantity of yeast, and that, after baking, the now porous mass is con- verted into wholesome and digestible bread. In like manner, the addition of a small quantity of a substance resembling yeast to any saccharine fluid changes its nature, renders it creamy with minute bubbles, and after a time ends by leaving the body of the fluid clear and transparent, with a sediment at the bottom and a scum at the top, but now converted into an alcoholic fluid, variously named beer or wine, mead or pulque, but always with intoxicating properties, and a flavour dependent on the source from which the sugar was originally derived. The singular features of the pro- cess are the minute quantity of the exciting agent that is required— a little leaven leaveneth the whole lump—the rapidity and certainty with which at ordinary temperatures the action takes place^ and the constancy of the result. In all cases the sugar origi- nally present is broken up into alcohol and carbon