EXPERIMENTS ON RELATIVE VALUE OF TIMBER PRESERVATIVES. 20I 



29. Experiments on the Relative Value of certain 

 Timber Preservatives.^ 



Professor Henry has recently carried out a series of experi- 

 ments on the relative value of certain antiseptics recommended 

 by various authors as means of protecting timber from the 

 attacks of fungi, or wood-destroying insects, and from the injuri- 

 ous effect of the soil, and we summarise below his chief results^ 

 as set forth in his pamphlet. The object of the experiments was 

 purely practical, for they had as aim the investigation of the 

 question as to the best preservatives to be used by private 

 individuals, or others unable to set up costly plant. Professor 

 Henry points out that a good preservative should fulfil the follow- 

 ing conditions : — the substance should be unalterable, and should 

 not only destroy pre-existing germs of destructive organisms, but 

 should prevent — indefinitely if possible — the access of new germs 

 from the exterior ; it should not alter the force of resistance, the 

 hardness, elasticity, and other qualities of the wood, but should 

 either leave these in their original state or improve them ; it 

 should penetrate easily to all parts of the wood, and fix itself 

 permanently within the elements; it should not be poisonous or 

 dangerous ; it should be of constant and definite composition ; if 

 possible, it should not have a strong or disagreeable odour, and 

 it should not change the colour of the wood ; finally, it should be 

 of a sufficiently low price to make it worth while to use it in 

 preference to replacing the damaged wood. 



Eight preservatives were chosen as subjects for experiment, the 

 selection being made from among those which previous experi- 

 ments seemed to point to as having considerable value. These 

 eight were as follows : — (i) Avenarius' patent carbolineum ; (2) 

 carbolineum, Lion brand; (3) gas-tar; (4) microsol; (5) antinon- 

 nine ; (6) antigermine ; (7) lysol; (8) hydrofluoric acid. Car- 

 bolineum is a commercial term for an extract of coal-tar contain- 

 ing creosote. The brand invented by Avenarius is distinguished 

 by its high density and viscosity, while the Lion brand is less 

 dense and less viscous. The tar employed was obtained from 

 the gas-works of Nancy. Microsol is a pasty mass soluble in 

 water, formed of copper sulphate united to some organic matter. 



^ Preservation des Bois contre la Potcrrittire par le sol, les Ckanipigiions et 

 les Insectes, par E. Henry, Professeur a I'ecole nationale des eaux et forets. 

 Berger-Levrault et Cie, Nancy. To be obtained from the author. Price 

 4 francs. 1907. 



VOL. XXI. PART II. O 



