EXPERIMENTS ON RELATIVE VALUE OF TIMBER PRESERVATIVES. 203 



produced by the reagent. Microsol has equal penetrative power, 

 but the degree can only be demonstrated by testing for copper. 

 Taking first the specimens exposed in the open, the following 

 results were obtained. Of the " control " specimens left in the 

 open without any preservative, the fir was the best preserved, and 

 after it the Aleppo pine. The specimens of oak, beech, and 

 poplar not treated were at the end of three years so decomposed 

 that their replacement would be necessary in actual use. But the 

 specimens treated with lysol, antinonnine, and hydrofluoric acid 

 were equally or more decomposed. On the other hand, the 

 specimens of oak, Aleppo pine, beech, poplar, and fir treated 

 with either of the brands of carbolineum, with coal-tar, or with 

 microsol, remained unaltered, and were as serviceable as at the 

 outset of the experiment. 



The second series, the specimens placed in the mine galleries, 

 showed the following results. First as to the controls ; after the 

 poplar the fir was the most altered, whereas in the open the fir is 

 the most resistant; the beech was also much altered, while the 

 heart of the oak remained sound. The specimens impregnated 

 with the two brands of carbolineum, with gas-tar, and with 

 microsol remained intact, and this is true of all the five species 

 experimented with. Thus these four preservatives proved them- 

 selves equally valuable in the case of timber in the open and 

 timber under shelter. The least certain of the four is, however, 

 the tar, so that the contest for the first place is limited to the two 

 carbolineums and the microsol. Antinonnine and hydrofluoric 

 acid had a favourable effect on the specimens placed in the 

 mine galleries, which is in marked contrast to their absence 

 of preservative action on timber placed in the open. The 

 specimen of fir treated with antinonnine and placed in the mine 

 galleries was perfectly preserved, while, as already mentioned, 

 the control specimen was much altered. 



The hydrofluoric acid also had a preservative effect upon the 

 sap-wood of oak. As to the lysol, it had no preservative effect, 

 and is to be rejected alike for timber under shelter and in the 

 open. The experiments with antigermine were less elaborate 

 than with the others, but they showed that this substance does 

 not prevent the development of fungus mycelia in the wood of 

 beech, while it has a preservative effect on fir. 



The result of the series of experiments then is to emphasise 

 the value of carbolineum and of microsol. The question as to 

 which should be employed can only be solved by a consideration 



