152 APPENDIX, 
Subcutaneous injections. in mice seldom produce the necrosis so com- 
monly observed when ricin is injected, butinvariably cause epilation 
at the seat of the injection. On the other hand, the action of abrin 
upon the conjunctiva is much more powerful than that of ricin. Ehrlich 
has succeeded in producing an immunity to the action of abrin 
similar to that obtained with ricin (ef. Vol. III., p. 305), Animals 
thus rendered refractory present a general and local immunity to 
the action of the poison ; they bear without injury doses four times 
as large as those which would prove fatal to an unprotected animal, 
whether administered internally or injected beneath the skin. Abso- 
lute immunity of the conjunctiva to the action of abrin may be 
obtained by its internal administration for several weeks. From 
these facts the author concludes that a substance, which he calls 
anti-abrin, is developed in the blood which completely counteracts 
the action of the poison. 
Immunity to the action of abrin affords no “peoteoant against the 
action of ricin, nor does the administration of ricin lessen the ac- 
tivity of abrin; a rabbit whose conjunctiva had been rendered insus- 
ceptible to the application of solid ricin suffered from an intense 
conjunctivitis when a solution of 1:10000 of abrin was applied to 
the part 
ROSACEZE. 
Otto of Roses. 
The results of the investigations on Rose Oil, which have been 
carried on for a long time in the Pharmaceutical Institute of Breslau 
University, have been published by U. Eckart ( Archiv. der 
Pharmacie, 229 [1891], 355). A body C*°H"*O, which is called 
“¢ Rhodinol,” forms the chief constituent of both German and Turkish 
otto; it boils at 216°—217°, and shows all the reactions of an alcohol. 
With acetic or benzoic anhydride it forms esters, which, however, 
during distillation, di te againinto their constituents. By treat- 
ment with halogen hydro-acids, Rhodinol chloride C’°H*’Cl, Rho- 
dinol iodide C°H'7I, and so on, are obtained. Oxidation with potas- 
sium bichromate and sulphuric acid converts Rhodinol into an alde- 
hyde, which the author calls “ Rhodinal” and which is believed to be 
identical with Citral. By phosphoric anhydride Rhodinal is trans- 
formed in Dipentene in abstracting a molecule of water. (Ber, von 
Schimmel & Co,, Oct., 1891.) 
