152 APPENDIX, 



Subeutaneoiis iujections in mice seldom produce the necrosis so com- 

 monly observed Avhen ricin is injected, but invariably 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 (cf, Vol. III., p. 305). Animals 

 thus i^endered 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, whieh 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 pi'otection 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. 



F 



ROSACEA. 



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 caUed 

 " Rhodinol," forms the chief constituent of both German and Turkish 

 otto ; it boils at 216° — 217°, and shows all the reactions of an alcohol. 



L' benzoic anhydride it forms esters, which, however^ 

 .tion» dissociate again into their constitvients. By treat- 



With 



,ill 



ment with halogen hydro-acids, Rhodinol chloride C^^H^^Cl, Rho- 

 dinol iodide C^^H'^I, 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,) 



