Miscellanies. 195 



adjusted tubes of large and small diameter to the oven, connected 

 them with a worm, and luted the mouth of the oven, they procured, 

 from the baking of two hundred loaves, by means of the large tubes, 

 about 50 litres ( = 131 gallons) of a limpid fluid, of a yellow color, a 

 sweetish taste, and emitting the odor of rye bread. Reagents indica- 

 ted the presence of acetate of lead resulting from the tubes of that 

 metal, acetic acid, but not a trace of alcohol. When the distillation 

 was performed through small tubes, the quantity of liquor obtained 

 vpas but three or four litres. Surprised at finding no alcohol in the 

 product, according to the statements of the English Journals, the 

 process was varied, but with the same result, and as a counter proof, 

 a quantity of alcohol was placed in a vessel in the middle of the oven, 

 but instead of a simjjle distillation, it was decomposed or absorbed by 

 the materials, and the quantity of acetic acid was sensibly augment- 

 ed. From this it may be inferred, 



1. That the materials of an oven are too permeable to prevent the 

 alcohol from passing through them. 



2. That at the temperature of 300° cent, the alcohol, if it exist, 

 is immediately transformed into acetic acid by the air contained in 

 the oven, or that which percolates through the materials. Whether 

 an oven constructed of iron plates would furnish alcoliol has not been 

 determined, at least in France, and to prevent the disappointment 

 into which speculators may be led, the writers were induced to make 

 known the result of their experiment. — Idem, tome 15, p. 190. 



6. Imitation Silver. — Cutlers, and all those who have occasion to 

 imitate silver, often purchase, very dear, an alloy called mailchior for 

 escutcheonsand other ornaments. It possesses considerable tenacity, 

 and may serve as a substitute for silver in certain instruments of sur- 

 gery. The two following prescriptions are both practised according 

 to the uses of the metal. Theij preparation requires the same pre- 

 cautions. 



Melt in a Hessian crucible of the capacity of a quart, twenty ounces 

 of nickel, six oz. of red copper, two oz. of salt of tartar, and three 

 oz. of good clear glass. When the mixture is liquefied, withdraw it 

 froim the fire, and when the crucible begins to lose its redness, pro- 

 ject into it 4 oz. of pure granulated zinc, and stir it carefully, that the 

 zjnc may be well diffused ; place it for a very short time over the fire, 

 and then pour it out on an eartl>en slab, removing carefully the sco- 

 rise. This mixture is somewhat brittle ; ihe following is more solid. 



