Part IL] Pearson: Antiseptic Treatment of 'limber. 
9 
deposit on the cells of the wood enclosing the copper-sulphate in the 
tissue and so overcomes the objection to which this salt is liable, i.e. 
being washed out of the impregnated timber. 
Corrosive Sublimate or Bichloride of Mercury. 
Corrosive sublimate is still used to a limited extent in some 
countries and its action is without doubt efficacious, but the sublimate is 
expensive and its poisonous properties a serious drawback. Further Mr. 
Howard F. Weiss of the American Forest Service states that the process 
is of such long duration that it cannot be recommended. It is used ex¬ 
tensively for preserving wood and seed specimens for museums. In 
Germany it is used for preserving telegraph posts, and there still remain 
in New England two plants where this substance is employed. Warth 
in his report (para. 4) advocates its use in India but only as an 
experiment. Looking to its cost and poisonous properties it cannot be 
recommended, especially as equally good and cheaper preservatives are 
procurable. 
Saccharine Solution. 
The Saccharine solution used in the Powellizing process is new 
amongst antiseptics. It is supposed that arsenic is one of the ingre¬ 
dients, though the composition of this preservative is a secret. The 
effect of Powellizing has so far proved very successful; time alone can 
prove its value in India. 
Compounds oe Fluorine and Dinitro-Phenol. 
In the Hottgar process, employed by the Rutgerswerken in Berlin 
sodium-fluor-silicates are used. These are not altogether suitable, being 
expensive and not very effective, while other fluor-silicates have the same 
disadvantages. For Military works in Austria, as also for telegraph 
posts, a solution of 3*25 k.g. of zinc to 100 litres of 3 per cent. Hydro¬ 
fluoric acid has been used as an antiseptic. The salt (ZnF 2 , 2HF) is pre¬ 
pared by a commercial firm, in a 20 per cent, solution only, so that to im¬ 
port to India 80 per cent, of water with which it is mixed would be ex¬ 
pensive. Of all the pure Fluoride processes those recommended by 
Hauptmann Basilius Malenkovic, as applicable in this country, are 
mixtures of chloride of zinc and sodium-fluoride, and secondly Dinitro- 
phenol. The mixture of ZnCL and NaF when used in the Open Tank 
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