Forty-fifth Annual Meeting. 17 



In the year 1835 Jean Baptiste Biot published hid memoir on 

 the circular polarization of light and its application to organic 

 chemistry,'-' which contains a table giving polarimetric data regard- 

 ing essential oils. This includes a sample of "naphte" rectified 

 by distillation, which examined by red light gave a rotation to the 

 left equivalent to 15.21° for a tube length of 200 mm. It is, how- 

 ever, very unfortunate that we have no information as to the source 

 of this very remarkable sample. 



Nearly fifty years later, in connection with their researches 

 upon the petroleum of the Caucasus,^ Markownikow and Ogloblin 

 examined the natural "white naphtha," as well as some petroleum 

 distillates, and finding these samples inactive they did not continue 

 this subject any further. In 1885, however, Demski and Morawski* 

 examined some of the more important mineral oils of commerce, 

 among which one rotated the plane of polarization 1.2° to the right. 

 In 1898 Soltsien^ found that the commercial paraffin oils are dextro- 

 rotatory, and that the amount of rotation increases with their spe 

 cific gravity. Since that time general interest has been awakened 

 in this subject, and petroleums from all parts of the world have 

 been examined polarimetrically. In general, it has been found 

 that the lightest and least colored oils (including the so-called 

 white naphthas) manifest little or no optical activity, while the 

 heavier, dark and viscous oils yield active products.^ 



In a typical Kansas oil, examined in connection^with the work 

 of the University Geological Survey, slight optical activity was 

 detected in the upper kerosene fraction which distilled between 

 250° and 300° under ordinary atmospheric pressure. The higher 

 boiling portions of this oil, after a fractional distillation under 

 diminished pressure, were dextrorotatory, the amount of rotation 

 gradually increasing with the rise in boiling point until in the 

 neighborhood of 280° at 27 mm. it reached almost one degree of 

 arc' 



In some oils a maximum activity has been observed in the 

 vacuum distillates collected at about 275°, and in the case of a 

 German oil a second maximum was reached at a temperature 



2. Mem. de 1 'Acad, de Sciences. ;.;, 39 ; 1835. See, also, "Die Polarimetrie der Erdole," 

 M. A. Rakusin, Berlin-wien, p. 6; 1910. 



3. Annaies de chim. et de phys. (6), t. II. 387, 1884. 



4. Dingler's Polytech. Jr., S5S. 82; 1885. 



5. Chemisches Centralblatt, 1898, I, 869, II, 455. 



6. Zaloziecki and Klarfeld. Chemiker Zeitung (1907), 1170. 



7. Univ. Geol. Survey of Kansas, vol. IX, p. 317; 1908. 



