502 Queries and Answers, 



case sacrifice the bark, and thus be compelled to give as much more for 

 the timber as would cover the price of the bark to the seller. The advan- 

 tage he anticipates from this stipulation is, that it would put a stop to dry 

 rot, which now makes such ravages in ship timber, and is the cause of 

 such enormous expense in the king's dockyards, In consequence of the 

 dry rot, instead of a ship's lasting forty or fifty years without needing 

 much repair, it scarcely lasts more than four or five. I am afraid that the 

 cost of the bark would prove so serious an addition to the expense, that it 

 would deter government from adopting the advice offered. I know little 

 or nothing of dry rot ; it is perhaps presumptuous in me to say any thing on 

 the subject ; but as great wiseacres seem somewhat puzzled to account for 

 it, and still more at a loss to find a remedy, I may perhaps be excused if I 

 offer a few suggestions on the subject, though they may be (like many 

 which have been already offered) perfectly useless. The general opiniom 

 seems to be, that the dry rot is owing to a fermentation which is produced 

 in the timber by the sap which it contains in consequence of being felled at 

 an improper time of the year; and the desideratum is, how shall we get the 

 bark for the tanner's use, and at the same time preserve the wood in a 

 state fit for naval purposes ? 



It appears, from the experiments of Darwin, Mr. Knight, and several 

 others, that the sap flows from the root through the sap-vessels in the al- 

 burnum into the leaves, where it is elaborated ; and then, descending again 

 between the bark and the wood of the previous year, it deposits another 

 layer of new wood, which the year afterwards serves as a channel for the 

 ascent of the sap. It is the practice of the peelers in this neighbourhood 

 to lop off all the branches of the trees, that they may bark them more con*- 

 veniently, as they peel boughs of less than 2 in. in diameter ; and it ap- 

 pears to me that if, instead of this plan, they were to allow them all 

 to stay on, and peel as far as they could go, without much endangering 

 their safety, say until they came to where the branches are 4 or 5 in. in 

 diameter, the value of the bark they would lose would be comparatively 

 small, both from its lightness, and the extra-labour required to procure it» 

 All the leaves of the tree being left on at the same time, the sap would 

 rise through the alburnum, and be elaborated by the leaves ;. but as there 

 would be no bark for it to descend by, it would be retained by the branches 

 above where they kept on their bark. I am no physiologist, and therefore 

 my theory may be as absurd and injurious in practice as another theory I 

 have had on the same subject. I had once an idea, that if the sap-wood 

 were sawed through all round the tree, early in the spring, this operation 

 would effectually prevent the rising of the sap, and the tree would be fit to 

 fell any time of the year. On mentioning, however, my plan to an intelli- 

 gent friend of mine, he assured me that it was the very worst that could 

 be adopted, as it was exactly what was done by the backwoodsmen of 

 Canada and the United States, who, when the trees are just coming into 

 leaf, saw through the sap, and decomposition takes place so rapidly, that 

 in a very few weeks the branches drop off, and shortly after the tree falls 

 to the ground quite rotten. Perhaps some correspondent versed in vege- 

 table physiology will do me and others the favour to elucidate those points 

 of the subject, which the vague notions I have expressed involve. I am, 

 Sir, yours, &c. — T. O. Clitheroe, Lancashire. 



American Sugar obtained from the Sap of Maple. — Sir, I send you a cake 

 of American sugar, made from the sugar maple y it is what the settlers use. 

 Why cannot we grow the tree, and make the like. Is the tree to be ob- 

 tained from the English nurseries ? — B. Coventry, June 25. 1832. 



We have tasted the sugar, and think it, as far as we can judge, in no 

 respect inferior to that sold in the shops as brown or moist sugar. Whe- 

 ther it is ever likely to become worth growing in this country, we are 

 more than doubtful; but we shall give what information we can on the 

 subject, for the use of those who may be disposed to try. 



