On the detection of strychnia as a poison : and the influence of morphia in disguising the usual colour-test / by John J. Reese.

  • Reese, John J. (John James), 1818-1892.
Date:
1861
Catalogue details

Licence: Public Domain Mark

Credit: On the detection of strychnia as a poison : and the influence of morphia in disguising the usual colour-test / by John J. Reese. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    is to immerse the body and hind legs of the frog iu the strychnia solution; when, after a shorter or longer time, depending upon the strength of the solution and the size of the animal, tetanic spasms will be produced, owing to the poison absorbed. A second method is to inject a few drops of a solution of known strength into the subcutaneous tissue of the thorax or abdomen of the animal. A third mode is to inject a similar solution into the stomach through the oesophagus. Either one of these methods will afford satisfactory results. The first one, or that by cutaneous absorption, was, I believe, that adopted by the distinguished discoverer; and as I found it a very convenient one, I also followed it in my own experiments. The extreme susceptibility of the frog to the influence of strychnia is truly remarkable. Long known as affording us one of the most delicate indications of the galvanic current, so as to be esteemed pre-eminently galvanoscopic, this little animal would appear to be no less sensitive to the action of the subtle poison now under consideration, so that it merits with equal propriety the appellation of strychniascopic. In experimenting with frogs with a view to determine the presence of strychnia in minute quantities, it is advisable to make use of very small animals—those, for example, whose bodies measure from an inch to an inch and a quarter in length, and which would weigh from twenty-five to fifty grains. The simple method which I adopted, and which I found to answer extremely well, was to put a small quantity of the strychnia solution—about a fluidrachm, or even half that quantity—into a deep conical glass vessel, such as an ordinary pint graduate measure, and then place the frog at the bottom. The shape of the jar insures the required immersion of the hind legs and body of the animal in the liquid, while the head remains perfectly free for breathing. Any efforts to escape are usually prevented by the sides of the vessel; or, if necessaiy, it should be pushed down again into the fluid—the object being to insure continuous contact. The subjoined expe- riments were undertaken by me with the twofold view first, of comparing the value of the frog-test with the other strychnia tests ; and secondly, of ascertaining if the presence of morphia would produce any modification of the usual effects of strychnia on the frog. Experiment 1. A frog weighing 45 grains was put into a solution of strychnia, one drop of which contained the 1-13,500th of a grain—(equivalent to about one grain in twelve fluidounces.) Convulsions were produced in four minutes. Expt. 2. A solution of one-half the strength of the preceding (or one grain in twenty-four fluidounces) affected a frog weighing 40 grains in five minutes. Expt. 3. A solution of one-half the strength of Expt. 2 (or one grain in forty- eiiilit fluidounces, or three pints) produced spasms in a frog weighing 28 grains in five or six minutes. Expt. 4. A solution of one-half the strength of the last (or one grain in six pints) affected a frog weighing 35 grains in eight minutes. In this case the animal was immersed only five minutes, and subsequently recovered. In the former instances they very soon died. Expt. 5. A solution of one-half the strength of that used in Expt. 4 (or one grain in twelve pints) produced the tetanic spasms in fifteen minutes. In this case also the animal recovered.