CALCEOLARIA, 
183 
hydrogen, and carbon, as well as ammonia; but whether it be all 
these in combination, or any one of them in excess, which effects 
the change, is not generally known. Here an ardent floricultural 
chemist might be an useful man in his generation, if he would 
only explain to us the cause of accidental colour in flowers, and 
how we might be able to produce them at pleasure. The custom 
of blooming plants in water, presents a fine field for chemical 
experiment, as to how far the tints of flowers would be affected 
by various chemical principles introduced into the water. In 
this view of the subject, namely, extending our knowledge and 
our means of artificial floriculture, there is yet much to be dis¬ 
covered and practically applied. 
We are quite certain that the colours of flowers are changed by 
some quality in the soil in which they are planted, but we are 
mostly ignorant of what that quality is. Even among plants in a 
state of nature, the normal colours are completely lost. The little 
Campanula rotundifolia is found with white as well as with blue 
flowers : and the Scilia non scripta is often met with white and 
flesh-coloured flowers growing in the midst of a bed of those of 
the natural blue colour. There is no accounting for these changes 
except by saying it is an accident! And, as happening to wild 
plants, there is indeed no means of even guessing at the cause; 
nor is there, even among highly cultivated plants, such as the 
Calceolaria , any appreciated indications why one individual plant 
shall exhibit white, and another have deep purple blossoms. 
It has been long ago noticed, even by cow-boys , that if a prim¬ 
rose, or a cowslip, happens to be dropped upon by one of the 
herd, the flowers of that plant will be brownish , not yellow, on 
the following year; and perhaps it was from this accidental cir¬ 
cumstance that florists were taught to enrich their flower beds 
with manure, as well to give colour as luxuriance to their plants. 
Be this as it may, it is a fact that cow-dung has this effect; but 
how it operates, or what quality of it is the actual agent, is, 
except to chemists, perhaps, unknown. 
The above observations are made with the view of calling 
attention to the particulars alluded to, and which should really be 
made a part of the florist’s studies in connexion with what may 
be called the capabilities of his art; for whenever there is any 
uncertainty or obscurity attending or hanging over the results of 
his practice, these he should endeavour to clear away. 
