36 
the plants with green tobacco leaves, took an acre of tobacco to save 
an acre of vineyard. Some said introduce small birds, but the pest 
was of so recent a date that the absence of small birds could not 
account for its spread. 
At last, a French naturalist, M. Planchon, went to America, 
whence it was believed the phy/loxera was imported, studied the 
insects and their enemies, and there found a nesting acarus, a species 
of American “plant lion,” which lived upon it ; and now, having 
introduced both the bane and the antidote, they were in hopes of 
checking the ravages of the piydloxera. 
Here he might pause, the lesson learnt being that Nature pre- 
served a balance if man let her alone; but if he interfered, and either 
killed off what he fancied noxious things, or imported pests, he would 
suffer detriment until either the antidote recovered strength on the one 
hand, or was imported on the other together with the pest. 
The PRESIDENT, Mr. Haselwood, in proposing a vote of thanks to 
Mr. Wonfor for his paper remarked, apart from the interest and 
instruction afforded, Mr. Wonfor’s paper shewed the importance of 
the right study of Natural History, and he would urge on all 
naturalists to use their best endeavours to extend the Society’s roll of 
membership. 
Mr. G. ScorT would like to know from some of the chemists 
present, in reference to a statement made at the last meeting, that the 
chemists had been able to manufacture from inorganic material 1,000 
substances identical with those said to be of purely vital origin, 
whether such was the case in the main? 
Mr. W. H. SMITH shewed that the chemist had been able to 
produce certain substances, such as essences and dyes, but that most 
of them had some organic source. 
Mr. HENNAH pointed out that the oil of lemon had been manu- 
factured by the chemist from inorganic substances ; but Mr. T. W. 
Wonfor subsequently asked from what substances that oil had been 
manufactured, and Mr. Hennah replied from turpentine, 
Mr. WONFOR then argued that in every case an organic sub- 
stances was taken as the basis on which the artificial essences, &c., 
were built up. 
