117 
planting in^ and all due attention paid to the removal of this 
magnificent shrub into situations, exposed, dry, and open to the 
full effects of the sun, we rarely, if ever, have seen it grow with 
that vigour which could be considered satisfactory. One in- 
stance apparently at variance with this opinion occurs to our re- 
collection, but here its success we found dependent on a moist 
red sand-stone rock two feet only beneath the surface. In con- 
sidering what description of earth,independently of peat, is best 
suited for the Rhododendron, we recommend alight sandy loam; 
and this may be improved by the admixture of decayed leaves, 
or other vegetable matter. Young plants may now be purchas- 
ed at a very reasonable price from any nurseryman, otherwise 
their propagation from seed is quite easy; and particularly de- 
sirable on account of the variation in tint and character of the 
plants so raised, the more especially if seeds be preserved from 
plants which have flowered near to other species. If care be 
taken to fertilize the flowers of one species with the pollen of 
another, (see Botanic Garden, No. 26’i) hybrids may of course 
be expected, many of which may now be met with of the most 
splendid character. 
lol Chemical CHANGES IN Veget.vbles. Very few subjects offer 
a greater degree of interest to the enquiring mind than the 
chemical changes continually going on in vegetal)le substances. 
All matter is composed of very few simple elements. Its vari- 
able character is produced by the varying proportions of these 
elements. The woody fibre of vegetables consists of Carbon, 
51.43, Oxygen 42.73, Hydrogen 5.82. An hundred parts of 
sugar is compounded of carbon 42.85, and 57.15 parts of Oxy- 
gen and Hydrogen in the proportions which constitute w ater. 
Hence the elements of sugar are nearly the same as water, with 
the addition of carbon. Wood is also composed of the same ele- 
ments, with a larger proportional of Hydrogen. TJiis subject 
has been introduced more immediately to our notice by Mr. 
Everitt, in a lecture before the Medico-Botanical Society which 
was reported in the Lancet, No. 753, from which we copy the 
following: “Mr. Everitt delivered a lecture on a peculiar class 
of chemical changes brought about in compound bodies, more 
particularly in organic compounds, merely by the jiresence of cer- 
tain agents, where these agents do not enter into combination with 
the substance acted on, either as a whole, or yield to them any 
IW AOCTAEIUM. 
