172 Method of preserving Lime fit for Mortar, &c. 



Many of these are nearly metallic, and weigh from ten to thirty 

 thousand pounds. From such a mass I have lately seen speci- 

 mens perfectly similar (judging from description) to those ob- 

 tained from the American mass of native iron, and which were 

 capable of being extended under the hammer. The circumstance 

 of the Brazilian mass being found where the surrounding country 

 is covered with a substance resembling an ore of iron is extremely 

 curious. Those who have a difficulty in believing the descent of 

 such mightv masses of matter from the atmosphere, miglit find 

 pleasure by inquiring as to the probability of these metallic ac- 

 cumulations being tlie jiroducts of ancient metallurgical opera- 

 tions; and whether the plentiful diffusion of iron ore in their im- 

 mediate neighbourhood is not the scoria surcharged with iron- 

 that had been evolved in the progress of these_, perhaps ante- 

 diluvian, manipulations. 



XLII. Method of preparing Lime, so ns to preserve it for a 

 long Time always ready for Mortar or JVliileivash. 



To Mr. Tilloch. 



Sir, — Weserving with pleasure the readiness with which 

 you insert in your useful Miscellany any information that may 

 be useful, I scud you the process employed in this part of the 

 world for preserving lime. Those of your readers who have oc- 

 casion to use lime must know, that when suffered to slack by the 

 moisture of the atmosphere it at the same time imbibes car- 

 bonic acid, and after a time returns to the state of unburnt lime. 

 If made up into mortar to be kept in a heap, it undergoes, though 

 more slowly, the same change ; and when not cjuite destroyed 

 is found to have lost much of its binding quality, by the mixture 

 of the outer dead part of the mass with the lime in the interior of 

 the mass. All those evils may be avoided by the German pro- 

 cess, which I doubt not' will prove acceptable to many of your 

 readers. I am, &c. 



Fr. Vaik, Jan. 6, 18ir, T. E. 



The Process. 

 Take the lime as soon as possible after it is burnt ; dig a pit 

 in the earth about seven or eight feet long and four or five feet 

 broad : — l)y this pit set a wooden trough, about six feet long, two 

 feet broad, and one foot deep. At one end of this trough cut a 

 hole about six inches square, before which nail a grating of iron 

 with the bars about a tjuarter of an inch asunder. Inside the 



trough 



