An experimental inquiry into the physiological action of ergot of rye / [Samuel Wright].

  • Wright, Samuel
Date:
[1840?]
Catalogue details

Licence: Public Domain Mark

Credit: An experimental inquiry into the physiological action of ergot of rye / [Samuel Wright]. Source: Wellcome Collection.

    5/90 (page 5)
    ed by insects, burning with a clear jetting flame, and being of less specific gravity than water, its activity may be trusted.* * Section II.—-Chemical Characteristics and Composition of Ergot of Rye. When moderately heated, ergot becomes light-coloured, loses its natural smell, and acquires the odour of roasted wheat, at the same time greatly diminishing in acti vity. Flour, which contains as much as one-third of ergot, rises without any difficulty when made into paste, though when baked, the bread is dry and brit¬ tle. When ergot alone is made into bread, it does not ferment, remains sad, or heavy, and crumbles when handled.-)- When ergot is boiled in water, it forms, if the preparation be concentrated, a deep claret-coloured solution, having the odour of ergot, and embodying its active principle. Continued boiling weakens the medicinal activity of the solution, and will, if suffi¬ ciently continued, render it inert. The cuticle does not peel off by maceration, nor can boiling, however protracted, separate it; but its colour is transferred to the interior of the grain, giving it a deep-red tinge. The solution obtained by boiling exhibits a white pellicle upon its surface, when cool, which is the oil of er¬ got altered by heat and moisture, and in this condition looks like common fatty matter. An infusion of ergot is thus affected by reagents. Litmus paper indicates the presence of a free acid. Caustic potassa renders it a fawn colour in a few minutes; flakiness succeeds, which ter¬ minates in a light brown precipitate.]; Caustic ammonia gives a bulky precipitate of a light pink colour. Lime-water, a light blue deposit. Carbonates of soda and potassa, no immediate ef¬ fect, but in a few minutes there is a deposition of a grayish-pink colour. The strong acids afford a yellowish flaky coagulum. lo- proved to be nothing more than plaster of Paris artfully coloured. (Lancet, 1830-31. Vol. i. p. 638.) And I have several times observed the ergot to be adulterated with common paste; a fraud, I suspect, of very frequent occurrence, though not of very easy detection ; for the process of baking generally modifies the starch, so that it can scarcely be indicated by iodine. The best way of testing it is to powder the suspect¬ ed sample, and, after'moistening with water, to triturate it gently with iodine, when, if a blue colour results, an impurity may be credited. If this process be not satis¬ factory, the specimen may be digested in ether ; if the ergot be genuine, a yellowish oily solution will result; if impure, little change will take place. * The lightness of ergot depends upon the presence of its oil, which reduces its weight considerably below that of sound rye: hence the ergotted ears stand upright, those, on the contrary, not diseased, bend down from their greater weight. A mea¬ sure that holds fourteen pounds of rye, holds only nine pounds of ergot. •j- I may here state, that in giving ergotted bread to dogs, they have invariably been less affected by it, than when a similar quantity of ergot has been administered in an uncombined state. + The action of caustic potassa upon an aqueous solution of ergot, prepared with¬ out heat, is somewhat different. When first added, it gives the liquid a greenish tinge, and a curdy precipitate falls. If an acid be then dropped in, the precipitate is redissolved, and the original colour restored.