OF ARTS AND SCIENCES. 1G5 



as I could not get such low melting-points as the foreign chemists, I have 

 been unable to find the cause of the difference between their results and 

 ours, I have succeeded in modifying the process for making borneol, so as 

 to make it superior even to the much improved form given to it by Im- 

 mendorff ; for I soon found that a better result was obtained if Iei?s alco- 

 hol was used, and upon reducing the quantity by one half, that is, using 

 five times the weight of the camphor, instead of ten times, as we advised 

 originally, I obtained with one and a third times the theory of sodium 

 a product* melting at 193° without purification, while increasing the 

 sodium to twice the theory gave me the same result as Immendorff's 

 with the larger quantity of alcohol, and three and a third times the 

 theory, that is, a crude product having the melting-point 19G^, which 

 was not raised by the use of more sodium, and gave by one crystallization 

 from ligroine t 52 9^, and in a second case 4-3%, of pure borneol, melt- 

 ing between 199° and 200°. This same melting-point was obtained 

 in four different experiments ; and that the yield was not better from 

 Immendorffs method was proved by following his directions carefully 

 in another experiment, the product of which gave, after treatment with 

 ligroine, not more than 50 <J^ of pure borneol. I should judge, too, 

 from the results of my experiments, that cooling and stirring the liquid 

 had a favorable action on the process, but their effect is compara- 

 tively small. 



The work described above has led me to the followinor method for 

 the preparation of borneol from camphor, which becomes in this way 

 one of tlie simplest and easiest operations in organic chemistry : — 

 10 g. of camphor are dissolved in 50 g. of common alcohol in a small 

 beaker, and treated with 6 g. of sodium added in pieces of from 0.1 

 to 0.2 g. At first, only two pieces are added at a time, the addition 

 of fresh sodium taking place only after what has been already put 

 in has disappeared ; but after the fourth gramme, a gramme may be 

 added at once, cut in pieces of the size mentioned above. The ob- 

 ject should be to keep up a gentle effervescence, and it is well to stir 

 the liquid frequently, to keep it cool by immersing the beaker in a 

 dish of water, and toward tlie end of the process, when the action has 

 become sluggish, to add from time to time a few drops of water to pre- 

 vent the liquid from becoming pasty. After all the sodium has been 



* As this substance is iilentical with the crude product described in my paper 

 witli Menkc, I am inclined to think tliat we must liave used less alcoliol tlian 

 the amount reconimended by us in that paper. 



t The crystanization from hgroine, as recommended by Immendorff, is far 

 superior to the crystahization from hot alcohol, used by Menke and me. 



