MENACE OF THE BORER.

Press, Volume LXI, Issue 18347, 2 April 1925, Page 4

MENACE OF THE BORER.

AN AUSTRALIAN REMEDY.

In the January issue of the Australian "Homebuilder," the remarks Mr G. B. Leith on tho ravages of the borer beetle in Victorian buildings wero quoted. Mr Leith stated emphatically "that all timbers must be rendered immune from borer before they are used in any building, and that- the State Housing I Commission was resolved to t>ee that this is done in all buildings under their control. He said that "tijc use of kerosene or creosote, although effective in cases of minor attack, does not giv» any permanent degree of immunity, and treatment now being adopted is of such a nature as to leave a residuary poison, which will give some degree of immunity. One of tho most satisfactory and effective treatments is to spray or eoat the affected timbers with a preparation containing benzol, creosote j and arsenic in solution." j As tho suggestion to use creosote with arsenic "in solution" appeared' to indicate that some new discovery hud hec;i mndo by our chemists, enquiries were instituted, and it was found that such was tho ease. White arsenic (arsenious acid) can now be dissolved at small cost in any of the woodpreserving or insectioidal bases, such as creosote, benzol, kerosene, raw oi* boiled linseed oil, coal tar, Stockholm tar, bitumen, eto. The solutions are stable solutions, and should require no stirring in anv climate. About '2{ per cent, of arsenic is stated to be an effective strength. As tho arsenic is actually held iu solution in these bases (not merely stirred in), it is not filtered) out by the jiores of the timber, but is carried in with tho base as far as the base itself is ablo to penetrate. An impregnable barrier of arsenic is thus formed within the timber, which will effectually prevent the ingress °r egress of wood-eating insects. As '•he boror beetle must eat her w.iy cut in order to broed, and as the young borers (larvae) eat their way in, it is elear that they must be killed by the arsenic, even if not already dealt with by the base fluid. Combining Methods. In effect, the chemists have sucecedr ed in combining the methods of treatment recommended by two of our leading entomologists. Mr "W. "W. Froggatt, E.Ti'.S., Government Entomologist of N.S.W., recommends the addition of arsenic to the wood-preserving oil.; (thia is rendered simple hy the new method'); whilst Mr C. French, jun., Government Entomologist for Victoria, strongly recommends creosote as deadly to the borer, either iilone or mixed with arsenic, as recommended by Mr Froggatt (vido "Journal of the Department of Agriculture of Victoria" for April, 1918). The new method of dissolving the arsenic give.-s the full benefit) of each of these recommendations in a simple and easily applied form.

The value of arsenic for tho protection of timber has long been known, mul it is used in various forms by several of the Government Departments, but in all cases recourse has had to .he made to caustic soda and water to dissolve the «rsenic. This involved a, loss in penetrative power of the base, as wfter will not penetrate as readily as oil. Tho caustic sod?, lias a destructive effect upon the fibres of the timber. Advantages. The advantages of the new method m-ay be summarised a_s follows:: — (1) Any borers or white ants presentin the timber are killed by the base. eggs are .ilso destroyed. (2) The arsenic penetrates the timber as far <r.s the base itself can penetrate. As arsenic is practically indestructible, tho barrier thus created will remain therein while the timber lasts.

(3) As white ants attack through the ends, or at weak spots : and as penetration is greatest fit these points, t'*» protection afforded against whitfe ant? is very great. (-1) The treatment can ho applied cold to the structural timbers of buildings in course of erection by spraying or painting. Under other circumstances, it can be applied by any convenient method, such as, immersion, boring and filling, etc. A selection can be made from any of the bases named, either singly or Several of them combined, selecting those most suitable for the timlier to be treated and its place iu the building, e.g., if tho timber is to be painted or polished., a non-stain-ing base can be selected. For floor joists, etc., creosote may be used. If it is to be dressed with oil, the arsenic can be dissolved directly into tho oil itself. In a few words, it is practically any of the existing methods of treatment —plus arsenic in solution. Copper, also, can be dissolved in any of these bases, either in addition to or instead of arsenic. This is of valu>; against all fungoid growths, dry rot, etc., particularly when used with creosote.

One outstanding advardage, of the new method is" its cheapness, both in first cost and in the cost of .application. It is a purely Australian discovery, and the whole of the contents are of local production. As our trade in local timbers is suffering very b?idly at present, largely on account of a belief that they are more readily attacked than certain foreign timbers, it is fitting that an Australian discovery in chemical science should come to the rescue.

MELBOURNE CITY HALL. Efforts to persuade the Melbourne City Council to erect a new Town Hall wore given unexpected prominence when the existing hall, which is encased by the municipal offices, was destroyed by firo within the past few weeks. Those who advocate a new hall do not indicate what they would , do with the present site. As a commercial proposition it is worth £3OOO a foot,, and as there are 313 feet to Swanston street alone, with other frontages to Collins street and Little Collins street, the Council could certainly make the greatest land deal in the history of Melbourne if they chose to sell. At present they have not made such a decision. When they do, the question of a new site must become a burning one. Some citizens favour a new hall at the extreme north of Elizabeth street, and others a site in the Treasury Gardens at the south end of Spring street. If the latter site shouTd bo chosen it would revive interest in the bold plan of a prominent engineer to project a street traffic bridge from Spring street across the width of the railway yards into Batman avenue. This bridge scheme is really paramount, but the Town Hall question is more spectacular, and serves at least to direct public attention to the necessity for opening roadways across the railway s'ards to relieve the glut of traffic over Priucc's Bridge.