516 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[January 6, 1872. 
These facts prove that the vapour of carbolic acid, even 
when most concentrated, fails to arrest putrefaction, and 
to prevent the appearance of germs; indeed, as seen 
with the beef juice, it does not even delay those pheno¬ 
mena, the portion suspended in the carbolized atmo¬ 
sphere putrefying as quickly as that kept in ordinary 
air. “ Here is a beautiful hypothesis slain by an ugly 
fact.” After these results it is impossible to conceive, 
as it would be absurd to expect, the infinitely minute 
quantity of carbolic vapour which can be tolerated in 
the wards of a hospital, or is capable of diffusing spon¬ 
taneously in an alleged infected medium, competent to 
destroy floating unseen germs and organic particles, see¬ 
ing that in the highest state of concentration, and all 
the conditions in its favour, it failed to affect visible 
germs and tangible organic particles.* 
(To be continued.) 
THE ODOURS OF PLANTS, f 
BY JAMES EIUTTEX. 
The subject of the phenomena of odour and colour in 
plants, and of the causes which induce or govern them, 
is one of considerable interest; and the relations which 
exist between the two are sufficiently striking. Thus, it 
has been statistically ascertained, and a very little re¬ 
flection will confirm the conclusion, that white flowers 
stand highest in number among fragrant species, next 
yellow, then red, and lastly, blue. And it is among 
white flowers that disagreeable odours are most seldom 
found, while orange and brown are frequently unpleasant 
in scent. In such calculations, however, it must be re¬ 
membered that the appreciation of odours is by no means 
the same to different people : scents which are agreeable 
to one, are often the reverse to another. The strong 
odour of Tagetespatula and T. erecta is not objectionable 
to some; while others, besides the well-known fox- 
hunter, are of opinion that the Sweet Violet is a “stink¬ 
ing flower.” There are even some unhappy beings—we 
trust they are but few—who cannot endure the scent of 
a rose. The sense of smell, too, is much more acute in 
some persons than in others; and w r e have frequently re¬ 
marked an analogy to colour-blindness in the want of per¬ 
ception of odours manifested by some among our friends. 
A good summary and, comparison of scents will be 
found in M. Lecoq’s ‘ Etudes sur [la Geographie Bo- 
tanique de 1’Europe,’ from which some of the following 
details are borrowed. In almost every case, however, 
additional instances of similarity will suggest themselves 
to the reader, especially if he be gifted with a keen nose, 
and a good memory for smells. In the first place, it 
may be laid down as a general principle, that a larger 
proportion of white flowers are fragrant than those of 
any other colour; yellow come next, then red, and lastly 
blue; after which, and in the same order, may be reck¬ 
oned violet, green, orange, brown, and black. 
Among white flowers, certain types of scent are very 
prevalent. Thus many Umbelliferous plants have a 
strong odour of honey, which is very marked in An- 
thriscus sylvestris , and is found also in the aquatic ra¬ 
nunculi : Eucalyptus glandulosa recalls the same scent; 
and in the almond and apricot we encounter it, qualified 
by that flavour of prussic acid which is so perceptible 
in the hawthorn when one does not inhale too closely 
the fragrance of its flowers. This scent is intensified in 
Spiraea Ulmaria ; in S. Filipendula it is modified by a 
soup<;on of the odour which is foimd also in the privet 
and in Actcea spicata , and attains distinctness in the 
elder. Many Rubiaceous shrubs have similar odours, 
and resemble certain Apocynece ; and the Philadelphus 
coronarius has so much affinity in scent with the orange, 
* See also, “ On the Relative Powers of various Substances 
in the Destruction of Microscopic Organisms,” in the Lancet 
of Aug. 6th, 1870. 
t Reprinted from the Gardeners' Chronicle. 
that it is often called the “mock orange bloom.” Other 
types of scent among white flowers are presented by the 
white lily, the jasmine, the tuberose, and the lily-of-the- 
valley. It is curious to observe, that among cultivated 
plants, white-flowered varieties are very often the most 
—if not the only—fragrant ones; this is the case with 
the white petunia [?] and a commonly cultivated white- 
flowered verbena [?]. It is also worthy of notice that 
many of the scents among white flowers are only plea¬ 
sant when in very small quantity, and become absolutely 
disagreeable when intensified; this is the case, especially, 
with the hawthorn and white lily. 
Among yellow flowers, the scent of the orange is often 
found, we may note, in the common broom, and in Biscu- 
tella saxatilis and other yellow Crucifers. The curious 
alcoholic odour which has earned for Nuphar lutea its 
English name of “Brandy-bottle” is found also in the 
yellow Brugmansia floribunda , as well as in the yellow 
catkins of Salix caprea. Hippocrepis comosa recalls the 
smell of cheese, and this odour attains its maximum in 
the blossoms of Genista Scorpius. The honey scent is 
found in several yellow-blossomed plants, notably in 
Galium verum and Mahonia intermedia. 
Roses and pinks occur to one at once, when sweet- 
scented red-flowered plants are referred to; but with 
these exceptions it is difficult to characterize the odours 
of plants belonging to this series. But among lilac 
flowers a great resemblance in scent may be traced; thus 
the sweet odour of vanilla, which is so powerful in the 
garden heliotrope, is found again in different degrees of 
intensity in Petasites fragrans , Valeriana officinalis, and 
the common lilac; we meet with it also in Plant ago 
media , which is exceptional among plantains in its fra¬ 
grance and in its coloured corolla. 
Blue flowers are very rarely fragrant, and when so, 
only in a slight degree. The blue variety of Phyteuma, 
spicata exhales a faint perfume, and one or two cam¬ 
panulas are slightly scented. Franciscea PPopeana has, 
however, deliciously fragrant blossoms, which recall at 
once the scent of the orange and the tuberose; but al¬ 
though at first blue, they soon lose their colour and be¬ 
come white. 
Certain species, the flowers of which are of sombre 
hues, are very fragrant. Thus in the early flowering 
Calycanthus prcecox, one finds a multitude of odours, such 
as rose, jasmine and tuberose, harmoniously blended. 
The night-flowering stock ( Alatthiola tristis ), Plesperis 
tristis, and one or two more, compensate by their fra¬ 
grance for the absence of beauty of colour; while other 
dark-flowered plants, such as the henbane, have an in¬ 
tensely disagreeable odour. 
Thus we see that it is not the most brilliant flowers 
which are the most fragrant, indeed, many of the most 
brilliant in colour have no scent whatever. The beau¬ 
tiful Malvaceae of equinoctial America, the pelargoniums 
of the Cape, the passion-flowers [?], the gladioli, and 
some of the most striking Leguminosce are destitute of 
perfume. 
One or two conclusions as to the geographical distri¬ 
bution of sweet-scented plants may be arrived at from 
the preceding facts, united with many more which space 
will not permit us to cite. We have seen that a large 
proportion of pale and white blossoms are fragrant; and 
it is ascertained that these predominate in northern re¬ 
gions. We may therefore conclude that the relative num¬ 
ber of odorous flowers is greater towards the poles than 
towards the equator. It w r ould seem that the too power¬ 
ful action of light and heat is opposed to the emanation 
of the odours of flowers ; and we see many species, which 
are scarcely fragrant during the day, become so in the 
evening or at night. But if the odours emitted by the 
blossoms are more frequent in the North, the reverse is 
the case with the essences enclosed in the glands. Plants 
with fragrant leaves, aromatic fruits, and wood pene¬ 
trated with essential oil, are scarcely found except in. 
warm or tropical countries. 
