443 



Zinc labels. — lu nurseries and horticultural establishments generally 

 it is necessary to attach labels to the differeut specimens, and when 

 these are exposed to the weather the writing on the label becomes 

 illegible in a few years, and if care is not taken to renew it, the inscrip- 

 tion will be lost. These labels are commonly made of wood, and the 

 inscription put on with a plumbago pencil. Sheet-zinc cut into any 

 convenient form and attached either by a slender point cut to the label, 

 or by a fine, copper wire, is the best material for labels. A special ink 

 for the inscription may be made by taking one part each of acetate of 

 copper and chloride of ammonium, and lialf a part of lampblack, and 

 mix these with ten jiarts of water. Keep it in a glass bottle with a 

 ground-glass stopper. Shake well before using, and write with a coarse 

 steel pen. The writing will resist tl^ action of the weather for years. 



Artijicial marble. — The manufacture of artificial stone is daily becom- 

 ing more important, as the demand for the article increases, and new 

 processes are being introduced constantly, looking both to the durability 

 and beauty of the products. The latest of these is the manufacture of 

 artificial marble by Signor Uaccotti, in London, England. It is said to 

 be very beautiful, and to cost but one-tenth the price of natural marble. 



Artijicial butter. — A commission, created by the victualing depart- 

 ment of the navy of France, reports a process for the artificial produc- 

 tion of butter, of which it is aftirmed that it will not become rancid by 

 age. The following is the process of manufacture recommended : 



Best fresh beef-suet is first meclianioally cut by means of circular saws fitted to a 

 cyliutler, aud is next placed in a vessel coutaiuing water, carbonate of potassa, and fresh 

 sheeps' stomachs previously cut up into small fragments. The temperature of this mix- 

 ture having been raised to 45° C, (112° F.,) the joint influence of the pepsine from the 

 stomachs, and heat causes the fat to be separated from the cellular tissue ; the fatty 

 matter floating on the top is decanted, and, after cooling, submitted to very powerful 

 hydraulic pressure; the stearine is used ip, candle-making aud the semi-fluid oleo- 

 margarine is used for making the artificial butter in the following manner: 50 kilo- 

 grams of the fat are poured, along with 25 liters of milk aud 20 libers of water, into a 

 churn, while there is added 100 grams of the soluble matter obtained by soaking some 

 hours in milk from cows' udders aud milk glands; a small quantity of annatto is also 

 added, aud the process of churning is proceeded with. The butter thus obtained is 

 well washed with cold water. 



Potassium — by a new method. — To procure the alkaline metals, potas- 

 sium and sodium, readily and cheaply, is a desideratum, not so much on 

 their own account as on account of the relation which these metals sus- 

 tain to the manufacture of aluminium. Professor A. E. Dolbear pro- 

 duces potassium by heating the sulphide of that metal, in an alembic, 

 to a bright red heat, in contact with iron filings, when the metal distills 

 over and is received in common coal-oil. The chemical reaction is a 

 very interesting one, though very simple. The sulphide of potassium at 

 a high temperature yields its sulphur to the iron filings, and the potas- 

 sium, thus abandoned, iDasses over as a vapor, and is condensed and 

 received under naphtha, or any other hydrocarbon fluid. Whether this 

 process will cheapen the alkaline metals, remains yet to be tested. It 

 is not probable that we will ever be able to obtain aluminium by a direct 

 process from its oxide, and as long as metallic sodium, or potassium, is 

 indispensable in the production of aluminium, that important metal will 

 correspond in price to the alkaline metals, by the agency of which alone 

 it can be obtained. 



Phosphoric acid.-^T^he occurrence of phosphorus in combination with 

 the ores of iron, whether as phosphides or phosphates of that metal, has 

 long been an annoyance to iron manufacturers, and many rich ores are 

 rendered worthless by the presence of phosphorus, rendering the iron 



