Foods : their origin, composition and manufacture / by William Tibbles.

  • Tibbles, William, 1859-1928.
Date:
1912
Catalogue details

Licence: In copyright

Credit: Foods : their origin, composition and manufacture / by William Tibbles. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    acid ; the free fatty acid then displaces the acid radical from alkalies such as sodium, potassium, or magnesium carbonate: 2C15H31.COOH+Na2C03 = 2Ci5H3i.COONa + C02 + HgO. ralmitic acid. Sodium palmitate. The fats which enter into the structure of nervous tissues are more complex than the ordinary fats, and, from possessing different characteristics, are called lipoids—e.g., cholesterin, lecithm, cerebrin. Like ordinary fats, they are esters formed by the union of glycerine with acids in the true ether fashion. But mstead of aU the hydroxyls being replaced by fatty acids, only two are so replaced ; while the third is replaced by phosphoric acid. Their construction is probably in this manner : Glycerine. Phosphoric acid. Glycero-phosphoric acid. (OH] fOH. CsHJohI + H3PO4 = CgHs-^OH [oh J IPO4H2. In turn two fatty acid radicals replace the remainmg hydroxyls, and glycero-phosphoric acid becomes lecithin—e.g. : rCi7H35.COO. Di-stearyl-lecithin = CgHg^, C17H35.COO. FinaUy, cholin, C2H4.N{CH3)3.(OH)2, replaces oxygen or hydroxyl from the phosphoric acid group m the molecule, and thus gives rise to the special lecithins or nitrogenized fats of the nervous tissues. Such lecithins always contain one atom of nitrogen and one atom °^Bes?dS''the carbon, oxygen, and hydrogen taking P^rt in the formation of the nutritive materials of foodstuffs, there are other elements Plants absorb by theii roots the inorganic phsophates, sSates, nitrates, and chlorides, of the soil.. The majority of these however only exist in the sap of the plant in a very dilute solution and il tire fo^-m of ions. Au dilute solutions — ^ P^^^^^^^^^ their salts in a dissociated or ionized form. Thus the phosphates are chiefiv dissociated into a metaUic cation and an acid anion. The latter'^^s a S^^^ anion ready for union with other -ns for ^^^^^^^^^ it has an affinity. One of its important ^?^P°^^,t\' '^ato^ phosphoric acid C3H,P0e aheady named, and th^/orm^tion^ which leads in vital processes to the ^^^'^'''''^'^^ ^1^^^^^^^ of the in turn is the chief link between the unorganized p^^osphoi^^^ earth and the organized phosphorus of our food tuff^ norckarly Proteins.—The construction of living prote ns is not cieauy the carbon dioxide of tlie at™spl«.e. Suceess^^ I
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