An Address on the Nature of Snake-Poison; its Effects on Living Creatures, and the Present Aspect of Treatment of the Poisoned
Authors: J. Fayrer
Journal: BMJ (1884)

THE communication which I have the honour of making to you this evening is in fulfilment of a promise made last April, after the discuision of a paper on a similar subject by Dr. Badaloni of Nocera, which excited considerable interest and some criticism with regard to the purely scientific aspect of snake-poisoning, its treat- ment, and its relation to the vital statistics of countries in which venomous snakes are more numerous than in our own (in this respect) more highly favoured one.I propose to describe the nature and the mode of action of snake- poison on living creatures; and, being most familiar with the Ophidia of India, I shall select some illustrations from that source, especially as it affords typical examples of snakes which are endowed with this terrible power of destroying life.Let me ask your attention to some points in the structure of the apparatus which is concerned with the elaboration and inoculation of the poison which it is the purpose of this paper to descrice.The order Ophidia has three subdivisions:1. Ophidia Colubriformes (innocent);2. Ophidia Colubriformes Venenosi; 3. Ophidia Viperiformes.The two latter are all poisonous-they are the Thanatophidia, and well merit this name in India, where they destroy, probably, 20,000 human beings annually.The general anatomical structure and distinctive characters of a snake are well known, but I will ask you to notice certain differ- ences between: 1. an innocuous and a poisonous snake; 2. between a poisonous colubrinie and a viperine snake.The crania, drawings, and dissections before you, illustrate these differences.Snakes are provided with sharp re-curved teeth, which are firmly fixed in the maxillary, palatine, and pterygoid bones; by the form and arrangement of these teeth, poisonous may be distin- guished from innocent snakes.The harmless snake has two complete rows of ungrooved small teeth, one-outer or maxillary, and one inner or palatine row; in the majority, there are from 20 to 25 teeth in the outer row.In the venomous snakes, the outer row is represented by one or more large tubular fangs, firmly ankylosed to the maxillary bone, which is movable, and, by its movement, causes the erection or reclination of the fang, so marked in Viperidne.In the innocent snake, the maxillary bone is elongated, and gives insertion to a row of teeth; in the poisonous colubrine, it is much shorter, giving inser- tion to only one or more teeth, the anterior and largest of which is the poison-faig.In the viperine snakes, the maxillary bone is reduced to a mere wedge, giving insertion to a long curved and tubular fang, which is a much more formidable weapon than the fang of the cobra, or other colubrine snake.These fangs, when reclined, are covered by a sheath of mucous membrane, in which lie also several loose reserve fangs, in different stages of growth.When the working fang is lost by accident, or is shed, one of the reserve fangs takes its place, be- coming fixed to the maxillary bone, and placed in communication with the duct of the poison-gland.The teeth vary considerably in the different subdivisions of the order.