\ 



On the Dry -Rot. 437 



.■A-hether die oak had attained this colour merely from age, or 

 pvved its preservation to the cause that produced the black co- 

 lour, I chcniicallv examined different specimens, and found in 

 .that investia^ation a far greater proportion of iron than could 

 fossibly ')e supposed to exist in the natural state of the tree. 

 To this iron I attribute the incorruptibility and high state of 

 preservation in which this antediluvian timber is found. This 

 extraneous iron must have been supplied from the ore of the soil, 

 or chalybeate waters, in this state of solution the iron would 

 penerrate the substance of the wood, unite with the astringent 

 principle, and give it not oidy the black colour, but communi- 

 cate such a density of texture as almost to resist the sharpest in- 

 strument. 



I base no wish to trespass with multitudinous remarks, nor to 

 fill pai>es with speculative theory. AHow me to express it as 

 my opinion, that the most effectual preventive of the dry-rot 

 would be to cut all navy timber at the season before stated, and 

 treat it as after mentioned. But should this period of cutting 

 he conceived incompatible with that important branch of na- 

 tional industry the leather trade, the same means will season 

 the new timber, and render it proof against the dry-rot, that 

 will cure it in the old, viz. by an application of iron in a state 

 of solution. This can be obtained at comparatively little or no 

 expense from a solution of green copperas, and will be found 9, 

 most effectual remedy, either as cure or preventive of that most 

 destructive canker. 



New timber, previous to its being marshallated, should be 

 cut up into ail the various forms which the ship-carpenter may 

 require, and allowed a time to dry. Then soak every chip to be 

 used in the navy in a well prepared solution, till it has acquired 

 the colour of new ink. This would completely counteract every 

 vegetative principle, and communicate that incorruptible dura- 

 bility and firmness of texture, so essentially requisite in navy tim- 

 ber, by the chemical combinations already described ; with this 

 addition, that the sulphur of the solution, penetrating the sub- 

 stance of the plank, would defend the vessel against the ravages 

 of insects. 



These are the grounds, outlines, and principles, of a plan, that, 

 if properly conducted, will, in my opinion, for ever banish all rot 

 and canker from the British navy. 



G. Inglis. 



E e 3 LXXVI. On 



