Snakes of the last-mentioned kind are especially difficult to manage. In order to avoid the risk of being bitten, it is always wise to begin by pinning down the head of the animal in a corner of its cage by means of a stick, and to seize it with a pair of long fenestrated tongs shaped like forceps. The operator then easily draws the reptile towards him and grasps it firmly by the neck with his left hand, always as close to the head as possible, at the same time raising the body quickly in order to prevent it from taking of anything. In this way the most powerful snake is perfectly under control. [Illustration: FIG. 85.--COLLECTING VENOM FROM A _Lachesis_ AT THE SEROTHERAPEUTIC INSTITUTE AT SÃO PAULO (BRAZIL).] [Illustration: FIG. 86.--CHLOROFORMING A COBRA IN ORDER TO COLLECT VENOM, AT THE FRENCH SETTLEMENT OF PONDICHERRY, IN INDIA (STAGE I.).] At Pondicherry, where is collected the greater portion of the venom of _Naja tripudians_ used by me for the vaccination of the horses that produce antivenomous serum, it is customary to chloroform the snakes in order to render them easier to manipulate. The reptile is placed in a large covered jar, containing a pad of absorbent wool impregnated with chloroform (figs. 86, 87), and in a few minutes it is stupefied. It is then grasped by the neck with the hands, and the edge of a plate is slipped between its jaws. On compressing the two poison-glands with the fingers, the venom dribbles out on to the plate. A detailed description of this technique will be found in a note kindly drawn up for me by my friend Dr. Gouzien, late head of the Medical Staff of the French Settlements in India, and reproduced further on in the section of this book devoted to documents. The note in question was accompanied by figs. 17, 18, 19, 86, 87, and 88, which are reproduced from photographs, for which I am indebted to the kindness of M. Geracki, Engineer of the Savanna Spinning Mill at Pondicherry, Dr. Lhomme, and M. Serph, Assistant Surgeon-Dispenser. The collection of the venom having been completed, the snake is put back into its cage again, the tail and the body being introduced first, and then the head. The lid or trap-door is half closed with the left hand, and, with a quick forward thrust, the right hand releases its grasp of the reptile and is immediately withdrawn; at the same time the left hand completes the closure of the cage. The snake is temporarily dazed, as though stunned, and it is only after the lapse of a moment that it thinks of darting open-mouthed at the walls of its prison. When it is desired to procure large quantities of venom, as is indispensable in laboratories where antivenomous serum is prepared, the endeavour must be made to keep the snakes alive for the longest possible time. It then becomes necessary to resort artificial feeding in the manner previously described (see p. 17), for they very often refuse to feed themselves.