On Dry-Rot. 25 



Lavoisier had stated muriate of lime as having heen obtauied 

 in his analysis, being dissolved with the muriate of magnesia in 

 the alcohol with which tlie solid matter obtained bv evaporation 

 had been lixiviated. I found no trace of it ; and its presence 

 after the evaporation to dryness, does not seem compatible with 

 that of either sulphate of soda, or of magnesia. Yet if the pre- 

 ceding reasoning be just, it is possible that alcohol, by its solvent 

 action, might cause its reproduction to a certain extent from 

 sulphate of lime. On the other hand, the entire insolubility of 

 sulphate of lime in alcohol, might prevent it from being acted 

 on ; this is even more probable ; and the result stated of mu- 

 riate of lime being obtained, is therefore, in all probability, to 

 be ascribed to error, principally perhaps to its not being distin- 

 guished sufficiently from muriate of magnesia, the quantity of 

 which is stated by Lavoisier evidently too low. 

 [To be continued.] 



V. On Dry-Rot. By Mr. John Shillibeer. 



To Mr. Tillocli. 

 T Plymouth, Dec. 12, ISI7. 



Sir, — ±F on perusing the letter which is below, you should 

 think proper to give it room in your Magazine, it will be greatly 

 esteemed. It has been submitted officially to the Navy Board, 

 and the writer of it has received the thanks of the Board for the 

 communication. 



T am, sir, 



Your friend and constant reader. 



" Walkhampton, near Plymoutli, Oct. 25, 181/. 



"Hon. Sirs, — The dry-rot which has made its appearance in 

 His Majesty's navy having excited general attention, I have been 

 led to reflect, not only on the cause which has jjroduced it, but 

 the probable mode of its prevention ; and the result of these re- 

 flections I shall beg to lay before the Honourable Board. 



" Any cure for the dry-rot in timber when once it is infected, 

 I believe, has not yet been found ; and the disease appears to 

 prevail more in the oak than in any other timber ; but the reason 

 is to me evident, as on account of "the value of its bark the mode 

 of treatment is very ditt^'erent to that of any other class. To 

 effectually prevent the appearance of the dry-rot, the tree should 

 be cut dowa about the end of December, or the coramencement 

 of January, and left with its bark on, instead of being cut down 

 in April, and having its bark stripped off, which is the mode ge- 

 nerally pursued in this country. From the great consideration 

 of the bark the durability of the timber has-been lost sight of, 



and 



