397 
of New Holland and Tasmania. 
bited by its so-called progenitor, has just claims to be considered 
as a distinct species; and I feel persuaded that Mr. Gould, on 
reconsideration of the matter, will restore the original name to 
the Astur Raii, and keep it as a distinct species. 
Art. XVIII .—On Solar Radiation, with a description of the 
Actinometer. By Lieutenant J. H. Kay, R. N., Director of 
the Magnetical Observatory, Hobart. 
It is an unquestionable fact, evident to all persons in any way 
acquainted with vegetable physiology, that light is the great agent 
by which all the changes in the juices of plants and trees are 
caused, and that the abundance of the vegetable secretions is in 
direct proportion to the quantity of light to which they have been 
exposed; moreover, on the contrary,that in situations where they 
are deprived of the formation of carbon, by the want of a suffi¬ 
cient action of the sun’s rays upon their own carbonic acid to 
produce it, so do their colours become paler, their smell more 
faint, and the flavour of their fruits less powerful. Light, there¬ 
fore, in the production of the vegetable kingdom, becomes an 
important element, beyond a mere question of luxury which odour 
and flavour may perhaps be considered; because, to mention one 
case only, the production of carbon by the action of light con¬ 
tributes in no small degree to the quality of timber, so useful and 
essential to the naval purposes of a great maritime nation; and a 
competent knowledge of the application of the principles of vege¬ 
table physiology, to horticultural purposes alone, may be unques¬ 
tionably turned to a very great account. In this colony, where 
the intensity of sunlight is not equal to that in more tropical 
countries which afford similar productions, the flavour of many 
fruits, such as the peach, the grape, and the melon, when pro¬ 
duced in the open air, cannot be compared to the fruits of coun¬ 
tries lying nearer the equator, where both the solar light and heat 
are much more powerful. In consequence of the decided im¬ 
portance of* obtaining a knowledge of the sun’s power, by compa¬ 
rative observations in different parts of the globe, the instrument 
