760 Retrospective Criticism. 



noses, to whose decision I submitted the plant, six pro- 

 nounced the iris to be destitute of odour, and four that it was 

 fragrant; but, of these last, one admitted that the scent was 

 so faint as at first to be scarcely perceptible. This plant, 

 therefore, it should seem, would be differently styled, either 

 scentless, or slightly fragrant, or highly odoriferous, according 

 to some peculiar idiosyncrasy in the different persons to 

 whose olfactory organs it happens to be submitted. Possibly 

 the case may be the same with the wood anemone. The above 

 are singular facts, and will, I hope, be put to further test by 

 some of your correspondents, and the results of their experi- 

 ments recorded in your Magazine. I may add, that a near 

 relative of my own^ whose sense of smell in general was acute 

 enough, could never perceive any odour in the honied blossoms 

 of the lime tree. I think, too, that there are some other 

 plants in the same predicament, though, at this moment, I 

 cannot call them to my recollection, I am. Sir, yours, &c. — ' 

 W. T, Bree, AlleslcT/ Rectory, April 9. 1832. 



These instances of difference in the power of olfactory per- 

 ception, as possessed by different individuals, call instantly to 

 mind the familiar truth that the differences in visual perception 

 are even greater and more common. Two very interesting 

 cases of great eccentricity in visual perception are recorded in 

 The New Edinburgh Philosophical Journal, in an article en- 

 titled, " Account of two remarkable cases of insensibility in 

 the eye to particular colours." — J.D. 



On Jiring the Fraxinella Plant (Dictdmnus Fraooinella L.). 

 (p. 503.) — The following remarks were intended to accom- 

 pany the annotations on Mr. Dovaston's Chit-chat (p. 504.), 

 but were delayed for the sake of inspecting some fraxinella 

 plants then in blossom, until too late for insertion at p. 507. : — 



The flower-stems, bracteas, peduncles, pedicels, calyxes, 

 backs of the petals partly, the filaments in the upper third of 

 their length, and the germen over the whole of its surface, are 

 thickly clothed with dark-hued somewhat orbicular glands or 

 ducts, each containing aromatic oil or resin, and seated on a 

 short and stoutish stalk, and tipped by a short and slender 

 hair. On that interesting subject, the combustion supplied by 

 the spikes of flowers of this plant on applying the flame of a 

 candle to them, my experience has been limited ; but my 

 firings have left me impressed that it is not a gaseous exhala- 

 tion that surrounds the flowers, which is ignited, but particles 

 of oil or resin, which the heat of the day has caused to trans- 

 ude from the ducts or glands already mentioned. I have 

 been able to procure combustion only by direct contact of the 

 candle's flame with some of these glands ; and combustion 



