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 carefully 

 in small plots of ground as nearly as possible equal in size and 

 quality ; equal weights of the dried produce of 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- 



