i68 ' Daors of Furnaces. Sugar from Carrots, l^c^ 



two inches tJiick of ftrong clay, mixed with a due portion of coarfe powder of broken crucible?, 

 which mafs will be held in its place by the heads of the nails, and by the projeding ftaples. This 

 mafs being put on wet, and gently dried, the cracks being carefully filled up as they appear, and 

 the whole well beaten together into a folid mafs, will, when properly burned on by the heat of 

 the fire, form a covering for the door, which will efFeiSlually defend it from all injury from the 

 fire; and the door, fo defended, will laft'ten times longer than it would laft without this defence. 

 The infide doors of the two brew-houfe fire-places which the Count fitted up at Munich arc 

 both defended from the heat in this manner ; and the contrivance, which has anfwered perfedlly 

 all that was expe6ted from it, has not been found to be attended with any inconvenience what- 

 ever. 



I have lately feen the patterns at Count Rumford's for calling a regulating door of his inven- 

 tion, which poflTefles the advantages of fimplicity, cheapnefs, andefFeci:, in a very ftriking de- 

 gree, it has neither hinges nor Aiding groove : it clofes with utmoft precifion ; and from the 

 very fmall quantity of work it requires to finifli it, the price ought not to exceed two or three 

 Shillings. I am not at liberty to anticipate the inventor, who will communicate it to the public 

 as foon as this can be moft efl^eSually done, namely, by dirediing them to a place where they 

 may fee what they are to imitate. 



V. 



Extrailion of Sugar from Carrots, &c. — Experiments on Barytes and Stront'ttes. 



Extras of a Letter from Mr. William Henry of Manchejier, to the Editor, dated 



June aoth, 1799. 



M 



.y friend, Do£lor Pefchier of Geneva, who is now at Vienna, fends me the following in- 

 formation refpe£i:ing the extradlion of fugar from carrots, &c. I fubjoin alfo fome experiments 

 of my own, on the fulphate and Prufliate of barytic and ftrcntian earths. 



" Profeflbr Jacquin rafped and cxprelTed 4olbs. of roots of carrots (daucus carota). The 

 juice, which was pretty clear, and of an agreeable tafte, was evaporated to the confiftence of 

 Jyrup ; clarified with fome albumen of egg, after being mixed with fome ounces of quick-lime ; 

 and filtrated. After cooling a few days, it contained, in the bottom of the veffel, fmall cryftals, 

 which, when wafhed in cold water, were white and diaphanous. To thefe fucceeded others of 

 a yellow colour. The whole of the cryftals amounted to 12 oz. ; they tafted exadly like the 

 pureft fuga!, and preferve their drynefs to this day. There remained about 41b. of a brown 

 fugar perfeftly agreeable to the tafte. 



« Second experiment. Three roots of beta cycla altiflima, weighing, after having been 

 peeled, 41b. were pounded and exprefled. The juice was thick, mucilaginous, and fweet, but 

 diiagreeably mixed with the tafte of turnips. It was evaporated, according to the method of 

 Mr. Achard of Berlin, without any addition, and (kimmed at intervals. This fcum was pro- 

 duced 



