BEE MANUAL. 303 
chemistry have been studied by the most eminent chemists, 
some of whom combatted the views of Liebig on this latter 
point (the source of nitrogen and its compounds), and Liebig 
himself seems to have modified his views on that point ; but 
there has been no difference of opinion about the saccharine 
matter, as to which Liebig’s doctrine will be found given 
unaltered in the latest colonial work on the subject, Maclvor’s 
“ Chemistry of Agriculture,” published at Melbourne a few 
years ago. 
SUPERFLUOUS NECTAR EVAPORATED IF NOT TAKEN BY 
INSECTS. 
That the nutritive quality of the plants in any growing crop 
is not diminished by the abstraction of honey from their blos- 
soms would appear to be evident from the fact already referred 
to, that those plants have actually thrown off the honey from 
the superfluity of their saccharine juices, as a matter which 
they could no longer assimilate. There would appear, on the 
other hand, to be good reason to believe that the plants them- 
selves become daily more nutritive during the period of their 
giving off honey, that is, from the time of flowering to that of 
ripening their seeds. This is a point upon which, I believe, all 
agricultural chemists are not quite agreed, but the testimony of 
Sir H. Davy is very strong in favour of it. In the appendix 
to his work already quoted, he gives the results of experiments 
made conjointly by himself and Mr Sinclair, the gardener to 
the Duke of Bedford, upon nearly one hundred different 
varieties of grasses and clovers. These were grown carefwly 
in small plots of ground as nearly as possible equal in size and 
quality ; equal weights of the dried produce uf each, cut at 
different periods, especially at the time of flowering and at 
that of ripened seeds, were “acted upon by hot water till all 
their soluble parts were dissolved; the solution was then 
evaporated to dryness by a gentle heat in a proper stove, and 
the matter obtained carefully weighed, and the dry extract, 
supposed to contain the nutritive matter of the plants, were 
sent for chemical analysis.” Sir H. Davy adds his opinion 
that this ‘mode of determining the nutritive power of grasses, 
is sufficiently accurate for all the purposes of agricultural in- 
vestigation.” Further on he reports, “ In comparing the com- 
