Protoplasm : its definition, chemistry and stucture / by Gustav Mann.
- Gustav Mann
- Date:
- 1906
Licence: In copyright
Credit: Protoplasm : its definition, chemistry and stucture / by Gustav Mann. Source: Wellcome Collection.
Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.
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![l_yte ’ for any substance ‘ which may split off, or unite with, M° and OH' ions, or, in other words, any substance which can play the part of an acid towards a base or that of a base towards an acid. According to this definition, water is an amphoteric electrolyte because its hydrogen-atom H and its hydroxyl-radical OH may be converted into the chemically active ions H° and OH' whenever water comes into contact with certain salts, as will be shown more fully later. Alco- hols (C„Ha„+,)OH are also amphoteric electrolytes. 'Ihus (C„H*«+.)OH can unite with sodium according to the equation (C„H.„+.0)-H-hNa°= G,H2«+.ONa-hH, when the alcohol remainder [C„H,„+.0]' plays the part of an acid, the feeble kat-ion H° being replaced by the strong kat-ion sodium, Na°. On the other hand, the hydroxyl-group OH may be replaced by a stronger an-ionic radical, such as a chlorine-ion; thus [C„H.„+,]°OH'+H°Cl'=C«H.„+.Cl-f H,0. This behaviour of alcohols depends on the presence of the OH radical, and it will readily be seen that other compounds which contain this OH radical will behave analogously. Such (^-com- pounds are, for example, serin and all phenols, <__>OH. Alcohols differ, however, from ordinary hydroxyl compounds, as they only form alcohol-salts in the absence of water. These alcohol-salts on coming into contact with water disso- ciate hydrolytically, because water is hydrolysed by alcohol- salts. The simultaneous presence of acid and of basic radicals in one and the same molecule as occurring in all amino-acids must of necessity lead to a weakening of the acid or basic characters of the molecule towards other individual molecules, and must also set up within the amphoteric molecule a ten- dency towards ‘ internal salt-formation,’ by which expression we mean that the acid and the basic radicals of an amphoteiic electrolyte will tend to mutually satisfy one another. When- ever this tendency becomes an accomplished fact, then the previously open-chain compound is converted into a ‘ ring- compound,’ Thus](https://iiif.wellcomecollection.org/image/b22471303_0038.jp2/full/800%2C/0/default.jpg)
