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214 quickly, that the touching body cannot penetrate its mass. If the smallest morsel of phosphorus is put into contact with a liquefied portion, the latter infallibly solidifies, though it be only a single degree below the limit of temperature necessary; this does not always happen when the body touching it is heterogeneous.

Sulphur presented the same phenomena as phosphorus; fragments of sulphur always produced the crystallization of cold fluid portions. Having withdrawn the bulb of a thermometer which had been plunged into sulphur at 120°, it came out covered with small globules of sulphur, which remained fluid at 60°; and having touched these one after another with a thread of glass, they became solid: although several seemed in contact, yet it required that each should be touched separately. A drop of sulphur, which was made to move on the bulb of the thermo-meter by turning the instrument in a horizontal position, did not congeal until nearly at 30°; and some drops were retained fluid at 15°, i. e. 75° of Reaumur below the ordinary point of liquefaction."

The 'Bulletin Universal' then proceeds to describe some late and new experiments of M. Bellani, on the expansion in volume of a cold dense solution of sulphate of soda during the solidification of part of the salt in it. The general fact has, however, been long and well known in this country and in France; and the particular form of experiment described is with ns a common lecture illustration. The expansion, as ascertained by M. Bellani, is $8/87$, of the original volume of fluid.

According to the 'Bulletin,' M. Bellani also claims, though certainly in a much less decided manner than the above, the principal ideas in a paper which I have published on the existence of a limit to vaporization; and I referred back to the Giornale di Fisica' for 1822 (published prior to my paper), for the purpose of rendering justice in this case also. Here, however, the contact of our ideas is so slight, and for so brief a time, that I shall leave the papers in the hands of the public without further remarks. It is rather curious to observe how our thoughts had been simultaneously engaged upon the same subject. Being charged in the 'Bulletin' with quoting an experiment from a particular page in M. Be1lani's memoir (which