The poison of the viper consists of a yellowish liquid secreted in a glandular structure (situated immediately below the skin on either side of the head), which is believed to represent the parotid gland of the higher animals. If a viper be made to bite something solid, so as to void its poison, the following are the appearances under the microscope:—At first nothing is seen but a parcel of salts nimbly floating in the liquor, but in a very short time these saline particles shoot out into crystals of incredible tenuity and sharpness, with something like knots here and there, from which these crystals seem to proceed, so that the whole texture in a manner represents a spider's web, though infinitely finer and more minute. These spiculÆ, or darts, will remain unaltered on the glass for some months. Five or six grains of this viperine poison, mixed with half an ounce of human blood, received in a warm glass, produce no visible effects, either in colour or consistence, nor do portions of this poisoned blood, mixed with acids or alkalies, exhibit any alterations. When placed on the tongue, the taste is sharp and acrid, as if the tongue had been struck with something scalding or burning; but this sensation goes off in two or three hours. There are only five cases on record of death following the bite of the viper; and it has been observed that the effects are most virulent when the poison has been received on the extremities, particularly the fingers and toes, at which parts the animal, when irritated (as it were by an innate instinct), always takes its aim.—F. T. Buckland.