The crystalline appearance of the second crop of crystals from the alcoholic solution after saponification, when melted and suffered to cool in a capsule, is similar to that of the first crop; in the capillary tube, begins to melt at 53°, fluid at 54°-55°, on cooling, crystals form in the tube at 51°, and is opaque at 50°. The melting point of the third crop of crystals was 50.5°. In ascertaining the melting points of the different fats described in this paper, I tried the various modes in use, and settled at first upon the following:--A beaker of distilled water (which must be boiled just before using, to prevent air globules settling upon the capillary tubes, which would falsify the result) is placed upon wire gauze upon a retort stand in front of a window, the thermometer hangs, by a string, in this water from another stand, and the lamp must be moveable from under the beaker glass. A piece of string is tied so loosely around the top of the (cylindrical) mercury reservoir of the thermometer, that the different capillary tubes may be readily slipped in and out on raising the thermometer from the water; the heat from the lamp must be such that the temperature of the water rises gradually; the capillary tubes are so placed that they lie closely to the mercury of the thermometer, and when the temperature approaches the melting point, the water is stirred with the thermometer to equalize the heat, the lamp is then removed, and the point of solidification observed in the usual way. I doubt very much the use of noting the point of solidification, as it is influenced so much by extraneous circumstances. The cooling of water and certain salts below their solidifying points, is well known, and the same must take place in these instances. Heintz has noticed how the thermometer rose ten degrees in determining the solidifying point of melted human fat. In one of my experiments, the fat in the tube was separated by minute air globules into three or four columns, quite close together; in observing the fusing point, they all melted at the same instant; but in solidifying, one would be quite clear while those on either side had become opaque, no matter how much the tube was stirred or vibrated by striking the beaker glass. After having observed this in several instances, I abandoned taking the points of solidification, and modified the process for the fusing point, by keeping the water as near that point as possible, and repeatedly lifting the thermometer and attached capillary tube out of the water for a few seconds, that the fat might solidify, and noting the fusing point as that at which it at once becomes liquid; this point is reached twice; first, when the water is being heated, and secondly, as it is cooling: I have found by repetition of the same experiment, that the degree thus obtained, is constant from the first, and I think gives the most accurate results. The mode of using capillary tubes for the fusing points, is convenient,