266 



Process de- 

 scribed. 



Results. 

 Charcoal, 



%vith a little 

 potash, lime, 

 and perhaps 

 silex. 



Concrete es- 

 sential oil. 



and a thick 

 brown oil, both 

 smelling strong 

 «f benzoin. 



ON THE COMPOSITION OF ALCOHOL. 



a determination of the number and proportion of the ele* 

 raents of alcohol. I have atteimptcd however, to attain a 

 knowledge of these by the same process. 



Through a red hot tube of porcelain, glazed internally, I 

 distilled 2183 grs. of perfect alcohol. The products passed 

 from this tube into a glass worm* surrounded with cold wa- 

 ter, and thence into a small globular receiver, which retained 

 the liquid products, and allowed the gasaes to pass on to the 

 pneumatic trough. 



The retort, which introduced the alcohohc vapours into 

 the porcelain tube, was kept at a temperature between 40* 

 and 50° R. [12-2° and 144° F.]. The distillation continued 

 twenty hours. I conducted it slowljs that scarcely any of 

 the alcohol might escape decomposition in traversmg eight 

 inches of redhot tube. From this process I obtained, 



1. In the porcelain tube 4^ g's- of charcoal, which sepa- 

 rated in the form of a thin film rolled up like a scroll, and 

 several inches long. This charcoal, being incinerated in a 

 platina crucible, left about a grain of ashes, in which I dis- 

 covered, by lixiviation with water and solution in muriatic 

 acid, the presence of potash, lime, and an insoluble resi- 

 duum, which might be silex. Mr. Proust had already found 

 silex and lime in alcohol. 



2. The glass worm was lined with the crystallized essen- 

 tial oil discovered in this process by Mr. Vauquelin. These 

 crystals presented themselves to the naked eye in the form 

 of thin, transparent, white, and yellowish scales: but with 

 the microscope some of them exhibited quadrilateral prisms 

 with diedral summits. They are very soluble in alcohol ; 

 and the solution becomes milky on the addition of water, if 

 the alcohol be not too abundant. These crystals, as well as 

 a very tliick brown oil with which they are mingled, and 

 which is scarcely volatile at the common temperature, have 

 a strong smell of benzoin. The weight of these two oils 

 collected and added together, both in the worm and in the 

 receiver, amounted to 4 grains. The receiver contained but 

 half a grain. 



♦ When I used a leaden worm, the liquor passing through it held 

 some lead in solhutioa. 



