470 Miscellaneous Intelligence. 



should be touched separately. A drop of sulphur, which was made 

 to move on the bulb of the thermometer, by turning the instrument 

 ill a horizontal position, did not cong^eal 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 Universel 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 us a common lecture illustra- 

 tion. The expansion, as ascertained by M. Bellani, is -^ of the ori- 

 ginal 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 va- 

 porization, 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 at the same time upon the 

 same subject. Being charged in the Bulletin with quoting an ex- 

 periment from a particular page in M. Bellani's memoir, (which 

 I did from another journal, in which the experiment only was de- 

 scribed,) I turned to the original place, and there, though I found 

 the experiment I had transferred, I also ibund another which I had 

 previously made on the same subject, and which M. Bellani had 

 quoted. 



I very fully join in the regret which the Bulletin Universel 

 expresses, that scientific men do not know more perfectly what has 

 been done, or what their companions are doing ; but I am afraid 

 the misfortune is inevitable. It is certainly impossible for any per- 

 son who wishes to devote a portion of his time to chemical expe- 

 riment, to read all the books and papers that are published in con- 

 nexion with his pursuit ; their number is immense, and the labour 

 of winnowing out the few experimental and theoretical truths which 

 in many of them are embarrassed by a very large proportion of un- 

 interesting matter, of imagination, and of error, is such, that most 

 persons who try the experiment are quickly induced to make a 

 selection in their reading, and thus inadvertently, at times, pass 

 by what is really good. 



12. Separation of Selenium from Sulphur. — Berzelius says, that 

 these substances, so much resembling each other in their general 

 properties, may be easily separated by the following process. 

 When sulphuret of selenium is fused with carbonate of potash, 

 the alkali not being in excess, the fused mass, dissolved in water, 

 leaves selenium undissolved and free from sulphur. 



