17^ On the Dry Rot 



Although it was not thought necessary at that time to repair 

 this ship below the middle wale, yet I have every reason to be- 

 lieve that the poison had begun its work in her timbers, from 

 light- water mark to her top-side, for in 1816 or 1817, in a perfect 

 calm she sank at sea, a poor miserable decayed hulk, a melan- 

 choly comment on the folly of cutting timber for vessels in the 

 winter months. By inquiry since, I have always found, that of 

 those vessels that last the longest, the timber of which they were 

 constructed was cut the farthest from December. 



The facts in this case entirely changed my opinion. Before, 

 I thought, because it was the general practice, that the winter 

 months were the best season to cut timber in ; now I began to 

 reason, to examine, and to compare. I fully believed that the 

 sap was the cause of the dry rot, and wherever that was stored 

 away, at the death of the tree, there would it make its first at- 

 tack ; I doubted, however, the botanical theory, that it is princi- 

 pally in its roots in the winter, and there protected from injury 

 by the frost ; for I could not clearly see how the roots of the 

 birch, beach and sugar maple, (although the quantity they will 

 bleed in a season, is partly accounted for in their being supplied 

 Iby the fibre roots, ) could contain their sap ; and if they could, 

 how it could be protected from the frost there, any more than in 

 any other part of the tree, when not more than one tenth part of 

 the roots were below the frost. I was therefore determined to 

 ascertain, if possible, where the sap reposed in trees, at diiFerent 

 seasons of the year. 



Accordingly, having cut a small oak staddle, on or about the 

 twentieth of June, 1815, I placed several pieces of it in the fire- 

 place, and put fire under them ; after a little while, there appear- 

 ed at the ends of the sticks a wet circle, describing the exact 

 thickness of the alburnum, and when they became considerably 

 heated, the steam rushed with violence from the tubes of the al- 

 burnum, and there was but a slight appearance of vapor over the 

 surface of the heart-wood. On or about the same day of the 

 month of December, of the same year, I had another small oak 

 staddle cut, and went through with the same process with sev- 

 eral pieces of it, and when they began to be heated, the whole 

 surface of the heart-wood, except a small circle enclosing the 

 pith, was wet, but the albmiium was dry, and when they were 

 fairly heated through, the steam rushed with violence from the 



