The quickness of the contractions, arising from the contractility of texture, is not like that produced by the animal or sensible organic contractility, which is uniformly more or less marked, according as the nervous influence of the stimulant acts more or less strongly. Every motion originating from the contractility of texture is slow, uniform and regular; it is only when the muscular texture is weakened that it diminishes; it does not increase except when this texture is more developed; hence it follows that the varieties of quickness can only be observed in different individuals, or in the same individual at different periods, and not, as in the exercise of the vital forces, from one instant to another. This is a great and remarkable difference between the two species of properties. Death weakens the contractility of texture but does not annihilate it; a muscle being cut retracts a long time after life has left it. Putrefaction alone puts a limit to the existence of this property. It is the same with regard to extensibility. I would observe however that while the muscles retain the vital heat, they have more power of retraction, than when the chill of death has seized them. Haller places on the same line and derives from the same principles, the phenomena resulting from the contractility of texture, which, with some slight differences, answers to his dead power, and those produced by the action of the concentrated acids, alkohol, fire, &c. on animal substances, which crisp, contract and acquire the horny hardness from the effect of these different agents. But there are many differences which essentially separate these phenomena from each other. 1st. The contractility of texture is very slight in the organs in which the faculty of having the horny hardness is very evident, for example, in all the organs of the fibrous, fibro-cartilaginous, serous systems, &c. &c. 2d. The contractility of texture is distributed in very various degrees, to the different parts; from the muscles and the skin, which possess the greatest degree of it, to the cartilages which seem destitute of it, there are many variations; on the contrary, the faculty of acquiring the horny hardness from the agents pointed out is almost uniformly distributed, or at least its differences are much less evident. 3d. One becomes nothing in dried organs, the other is evidently preserved for many years, as parchment is a proof. 4th. The first clearly receives an increase of power from life, especially in the muscles; the second appears to be hardly modified by it. 5th. This always exhibits sudden effects, rapid contractions. To feel the contact of the fire, of the concentrated acids or alkohol, and to assume the horny hardness, are two phenomena which the second brings together in the animal parts; the contractility of texture, on the contrary, exerts itself but slowly, as we have said. 6th. This last can never give to the parts, the muscles especially, that remarkable density which