Some experiments made by a friend of Dr. Bell seem to present different results. This gentleman had received a living Rattlesnake from America, intending to try the successive effects of its bite upon some Rats. He introduced one into the cage with the Snake: it immediately struck the Rat, and the latter died in two minutes. Another that was placed in the cage ran to the farthest corner, uttering cries of distress. The Snake did not attack it immediately; but after about half an hour, on being irritated, it struck the Rat, which, however, exhibited no signs of being poisoned for several minutes; nor did it die for about twenty minutes after the bite had been inflicted. A third Rat, remarkably large, was then introduced into the cage, and exhibited no signs of terror, nor did it seem to be noticed by its dangerous companion: after watching some time, the gentleman retired to bed, leaving the Rattlesnake and Rat in the cage together. In the morning the Snake lay dead, and the Rat had supped on the muscular part of its backbone. Unfortunately, Dr. Bell does not remember at what season this experiment took place, but thinks it was not in very warm weather. The climate of France differing only slightly from that of the United States, it is consequently well adapted for the production of Rattlesnakes. If a living male and female of these dangerous _Crotalidæ_ were to escape from a menagerie, they would soon infest the country with their terrible progeny. It is for this decisive reason that public exhibitions of Rattlesnakes are forbidden in France. Nevertheless, two or three may be seen in the collection of the Museum of Natural History at Paris, miserably installed in a chest, which is quite unworthy of this establishment. The Rattlesnakes are enclosed in a double cage, and every measure of precaution is taken which prudence demands. It is a remarkable fact that the poison is secreted after death. Dr. Bell, in his "History of British Reptiles," adduces the following as evidence of the facts:--He was dissecting very carefully and minutely the poison apparatus of a large Rattlesnake, which had been dead some hours; the head had been taken off immediately after death; yet, as Dr. Bell continued his dissection, the poison continued to be secreted so fast as to require to be dried up occasionally with a sponge or rag: and his belief is, that there could not be less than six or eight drops of the poison. It is obvious that such experiments require the utmost caution, seeing that preparations are not without danger.