SECTIONAL TRANSACTIONS.—K*. 493 
Pending the acquisition of such data, tests of wood preservatives and insecticides 
for the prevention and control of wood-boring insects in this country are strictly 
limited. An outline is given of the type of test which is at present possible, and a 
parallel is drawn with similar work in progress in India, Australia and other countries 
where termites (white ants) present the most serious timber insect problem. 
(4) Mr. J. Bryan.—Methods of Applying Wood Preservatives. 
Assuming the necessity of deep impregnation of the antiseptic for the preservation 
of exposed timbers, various methods are discussed of obtaining the desired impregna- 
tion. The various standard methods of impregnation by pressure difference are 
described, as well as methods depending on the diffusion of water soluble preservatives. 
Incising as an aid to the impregnation of refractory timbers is of comparatively 
recent introduction, but is now being used commercially for Douglas fir railway 
sleepers. Different methods of incising and their application are discussed. 
(5) Mr. W. G. Camppett.—A Chemical Approach to the Study of Wood 
. Preservation. 
The natural durability of certain woods is explained by the presence in such 
woods of extraneous components which are toxic or otherwise intolerable to wood- 
deStroying organisms. It would appear that the majority of these natural 
preservatives are merely specific in their action, since, with few exceptions, all woods 
are susceptible to decay in one form or another. It is suggested that the scientific 
investigation of the problems of wood preservation can be materially aided by 
concomitant studies of the intimate biochemical relationships which exist between 
decay organism and host. 
An account is given of chemical methods which have been used to indicate the 
ultimate effect of insects and fungi on wood substance. 
Exhibition illustrating Wood Preservation, by the British Wood 
Preserving Association. 
Friday, September 25. 
EMPIRE ForEstRY :— 
(1) Address by Sir ALEXANDER Ropeerr, O.B.E., Chairman of Depart- 
ment of Forestry.—Forestry in the Empire during the last 100 years. 
In attempting to compile a short account of Forestry in the British Empire during 
the last hundred years I have been struck by the fatt that almost the whole of the 
history of scientific importance, with a few notable exceptions such as India, is 
confined to the present century. It is true that forests have played quite a large 
part in the development of great countries such as Canada and Australia, but Forestry 
as a science has been until recently entirely neglected in many parts of the Empire. 
I would go even farther and say that many of the most important doctrines held by 
the forester have been consistently violated on a very large scale, with the result 
that the forest capital of several important countries has now been very much reduced. 
In the majority of the places concerned the story has been very much the same. 
The forests, if not actually regarded as an incumbrance of the ground and a hindrance 
to the ithmediate development of the country for the purposes of agriculture, were 
considered to be a species of gold mine from which all the valuable products could 
be extracted and sold, none of the revenue so realised being put back in the form 
of maintenance and improvement. There were a few striking exceptions to this 
process, India being the most important, and Ceylon, Mauritius and New Zealand 
are among others which may be mentioned. 
It is probable that the exploitation of forests, at any rate in the tropics, began 
with the practice of shifting cultivation. The practice has been widespread in many 
parts of the world up to the present day, and was prevalent among the Mayas of the 
ancient civilisation of Central America. Patches of forest are cut and burned and 
one or two crops are taken off the ground before the cultivator moves elsewhere to 
repeat his felling and burning. This destructive method of cultivation has un- 
doubtedly been responsible for many changes, and usually deterioration, in tropical 
