* unt eel 
NOTES ON SCIENTIFIC RESEARCH. 75 
Preserving effect of essential oils. 
As stated on page 131 of our Report of April 19138, J. L. Rippetoe and L. E. Wise 
studied the development of mould fungi in glucose or sugary peptone solutions in the 
presence of various essential oils, in order to investigate the preserving influence of 
these. For the same purpose, ©. B. Cochran and J. H. Perkins*) examined the action 
of different essential oils on the fermentation caused by yeast in cane sugar and 
glucose solutions. The results are given in the form of tables. For this reason, it 
is not easy to give a summary of the work, so that we must refer the reader to the 
original for particulars. 
Destruction of typhoid fever bacilli through essential oils. 
In the course of their investigations on killing typhoid bacilli in the organism of 
rabbits, E. Hailer and E. Ungermann®) tried the destructive action of some essential 
oils or their constituents on bacteria. The preparations were applied partly per os, 
partly per rectum, in some isolated cases also intravenously and intraperitoneally. 
Thymol proved to be efficacious; carvacrol, phenetole and anethole, on the contrary, 
ineffective. Terpine hydrate, borneol, citronellal, carvone and cineol possessed a 
remarkable influence on typhoid bacilli in rabbits; pinene, carvene, linalool, terpineol, 
camphor and camphoric acid did not make the virus disappear. Turpentine, juniper 
and peppermint oils showed no influence on the infection, whereas Ceylon cinnamon 
oil, if applied through the rectum, and sandalwood oil, when introduced through the 
stomach, killed the typhoid bacilli in the organism of rabbits. 
Haemolytical action of terpenes. 
For the sake of completeness, we would mention a treatise by N. Ishizaka*) on the 
haemolytic action of terpenes and the relation between chemical constitution and 
action. If the substances are classified according to their solubility (terpenes, terpene 
alcohols and terpene ketones), one notices that in the most closely allied, chemically 
speaking, the reduction of the surface tension of equimolecular solutions shows inverse 
proportions, z.c. the smaller the solubility, the greater the reduction of the surface 
tension. This rule does not hold good if there are certain differences in the chemical 
construction. 
If the constitution is otherwise the same, unsaturated compounds are more readily 
soluble than saturated ones. The double linking in the carbonyl group is of similar 
importance for the solubility as the ethylene linking. The great solubility of carvone, 
compared with that of dihydrocarvone and carvotanacetone, explains itself by the 
connection of a double linking and a carbonyl group by means of the CH group. The 
Same occurs in menthenone. The degree of haemolytic action of terpene derivatives 
proved to be dependent upon the purely physical properties, e.g. upon the alcoholic 
or ketonic nature. Some of the substances investigated, and unsaturated more than 
saturated ones, changed the blood-pigment into methaemoglobin. With alcohols and 
camphor there was no action at all, it was feeble with menthone, a little stronger 
with tetrahydrocarvone, dihydrocarvone and carvotanacetone, fairly strong with carvone 
and strongest with carvenone and menthenone. As for hydrocarbons, menthane and 
cymene did not cause any indication of haemolysis. Terpinene showed a considerable 
haemolytic power with the formation of methaemoglobin. 
1) Journ. Ind. Eng. Chemistry 6 (1914), 304, 306. — 7) Arbeiten a. d. Kaiserl. Ges. Amt 47 (1914), 303. —.- 
3) Arch. f. exp. Pathol. u. Pharmakol. 73 (1914), 194; Chem. Zentralbl. 1914, I. 1292. 
