— I03 — 
follows that the value — may vary within very wide limits. It will 
increase, on the one hand, if the pressure in the apparatus diminishes, 
and therefore when a vacuum is employed, and on the other hand, 
if the temperature of the oil which is to be distilled is raised. 
These facts, however, are not new to the essential oil industry. 
The more simple case, in which the steam passes through the oil 
present in the copper and heated by the jacket or worm, has been 
employed in practice as long as water vapour in tension has been used. 
With regard to the other case, that of distillation in vacuo with 
direct introduction of steam into the heated oil, — this has been used 
in our factory on the largest scale for more than a decade. And 
we do not believe that we are mistaken if we say that also in other 
essential oil factories this method of distillation is already known. 
In our next Report we hope to deal further with these interesting 
examinations. 
On the essential oil industry of the United States in the year 1902, 
Pietrusky^) gives some particulars based on the Twelfth Census 
Report of the United States. Natural oils are produced at 97 places, 
giving employment to 167 w^orkmen; the comparatively small number 
of the latter is explained by the fact that the oil-production is carried 
on chiefly by farmers in their houses, with very simply constructed 
retorts, which, in many cases, are portable. Of the most important 
oils, such as peppermint, sassafras, and wintergreen oils, the methods 
of production, yields, and quantities produced are given. The manu- 
facture of synthetic oils is carried on in four factories; the same number 
of works produce vanillin. The import and export figures for the 
year 1898 to 1902 are very remarkable; whilst the value of the im- 
ports of essential oils increased from 1,51 to 2,09 million dollars, the 
value of the exports decreased from 201000 dollars in 1898 to 
166000 dollars, but reached the former level again in 1902. The export 
of peppermint oil, however, has continuously fallen off, from 145 000 lbs. 
in 1898 to 36000 lbs. in 1902. 
Pharmacologico-physiological notes. 
G. Pegurier^) recommends the prescription of menthol for internal 
administration in the form of mixtures shaken with gum arabic — 
for example, menthol 0,03 to 0,05 gm., syrup, gummos. 120,0 gm. — , as 
such mixtures are always identical, and menthol can be properly 
divided in this manner. 
^) Chem. Industrie 26 (1903), 618. 
^) Apotheker-Zeitung 19 (1904), 54. 
