Chemistry and Physics. 413 



the followiug conclusions in regard to diffusion upward through 

 fuller's earth : 1. With a solution of benzine and paraffin oil, 

 the benzine tends to collect in the lower part, and the paraffin oil 

 in the upper part. 2. When crude petroleum is used, the oil that 

 is displaced by water from the earth of the ujjper part has a lower 

 specific gravity than that obtained in the same way from the 

 lower part. 3. As the fractionation proceeds the range of specific 

 gravity in succeeding fractions becomes smaller, indicating a 

 tendency towards the production of mixtures which will diffuse 

 without change. 4. In the fractionation of petroleum the lighter 

 portions, toward the top become gradually freer from unsaturated 

 hydrocarbons and sulphur compounds. 5. Fuller's earth tends to 

 retain the unsaturated hydrocarbons and the sulphur compounds, 

 thus exercising a selective action upon the oil. — Amer. Ghem. 

 Jour., xliv, 251, h. l. w. 



3. Vaciciim-tight Seals between Iron and Glass. — It has been 

 found by H. J. S. Sand that an iron wire sealed into glass may 

 be made vacuum-tight by passing over the protruding wire, 

 while the glass is still hot, a small piece of heated steel tubing 

 and pushing this into the soft glass for a distance of a few milli- 

 meters. After cooling, the outer end of the tube is soldered to 

 the wire. The explanation is given that the tube by its contrac- 

 tion compresses the glass within it and thus forms an effective 

 seal. Tubes into which iron wires l""" diameter have been 

 sealed in this manner have been exhausted to a cathode-ray 

 vacuum and have maintained this for four months, up to the 

 time of publication. It is not yet certain that the seals will have 

 a practical importance in replacing platinumi in the case of rapid 

 wholesale manufacture. The author points out that, as far as he 

 is aware, previous proposals to replace platinum for this purpose 

 by iron-nickel alloys or thin, flat strips of copper have met with 

 little success. It is to be hoped that the method under consid- 

 eration or some other satisfactory process will soon be devised 

 for the saving of platinum. — Ghem. Nevis, cii, 166. h. l. w. 



4. The Structure of Meteoric Alloys. — W. Guertlee has 

 discussed the structure of the iron-nickel meteorites from the 

 point of view of modern metallography. Frankel and Tiemann 

 have previously reached the conclusion that the meteoric structure 

 is metastable, since upon heating to 800° C. the material then 

 behaves like artificial alloys, and shows no evidence of again 

 attaining the well-known meteoric structure. Guertler's conclu- 

 sion, which appeal's to be well sustained by his arguments, is, in- 

 short, that the meteoric structure is a stable one requiring an 

 exceedingly long time for its formation. He believes that the 

 temperature at which the change takes place is comparatively 

 low and consequently very slow, and that there is no need to 

 assume a metastable condition in the natural alloy. — Zeitschr. 

 physikal. Ghem., Ixxiv, 428. H. l. w. 



5. Liquefaction of Helium. — H. Kamerlingh Ounes describes 

 his method of liquefying helium and states its properties. The 



