Page:The Zoologist, 4th series, vol 5 (1901).djvu/259

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Merck's Annual Report for 1900, a publication recording that year's advances made in clinical and pharmaceutical knowledge, is an interesting contribution on strychnine nitrate, which has for a long time been employed for the destruction of animals or birds of prey, and when applied internally has generally acted as a rather rapid and certain poison. Complaints have, however, been made for a number of years to the effect that at times strychnine has shown itself ineffective, especially with large animals, which has induced the writer to enquire into the causes of this phenomenon. Strychnine and its salts—in particular its nitrate—which is commonly used for poisoning purposes, are, chemically, very stable compounds, and their toxic efficacy remains unchanged for years. Its occasional inefficiency can therefore have its cause exclusively in the mode of administration, the state of the body, especially the extent to which the stomach is charged, and the presence or absence of the tendency to vomit. From Feser's experiments it appears that strychnine nitrate may be administered internally to Dogs in the solid form without detriment to the degree and promptness of its action. This mode of administration, which gamekeepers and sportsmen are compelled to adopt, has, in six experiments of Feser, invariably resulted in the animals' death, whereas they recovered if the same dose was given in the form of a solution. Feser ascribes this result to the rapid solubility of the strychnia salt in the stomach of Dogs, and the more rapid absorption of the concentrated salt solution.

It is of the utmost importance that the poison should be correctly dosed. According to Kobert the lethal dose of strychnia administered subcutaneously amounts to 0·75 mgrm. ($1/90$ gr.) per kilo ($2 1/5$ lb.) in the case of Dogs. Feser fixes, however, 0·5 mgrm. ($1/120$ gr.) per kilo ($2 1/5$ lb.) as the subcutaneous dose of strychnia nitrate which kills a Dog with certainty, whilst 1 mgrm. ($1/64$ gr.) per kilo ($2 1/5$ lb.) produces the same result with certainty if given internally. According to Fröhner the minimum lethal dose is for Cattle 0·3–0·4 grm. (5–6 gr.), Horses 0·2–0·3 grm. (3 to 5 gr.), Pigs, 0·05 grm. ($3/4$ gr.), Dogs 0·005–0·02 grm. ($1/12$ to $1/3$ gr.), Cats 0·002–0·005 grm. ($1/32$ to $1/12$ gr.). Unfortunately, data have hitherto been lacking