to Place this in a copper boiler over a slow fire, stir it well until the temperature rises to 149° to 158° F., when a partial formation of sugar will take place, but this sweetening must not progress too far. Then turn out the thin paste into a flat cooler and stir it from time to time. As soon as the temperature of the paste has fallen to 59° F. transfer it to a tub or vat, and add to every 15 gallons of the paste 1 quart of beer-yeast, which will throw the mass into brisk fermentation in the course of 12 hours. This preparation is a good yeast for bakers' and brewers' use, and will continue fresh and active for 3 days. It should be occasionally stirred. Cramer's Process of Preparing Pressed Yeast from Beer-yeast. I. Press the raw beer-yeast in a bag of fine silk bolting-cloth under water, whereby even the finest constituents, mechanically mixed with the yeast, will remain in the bag. 2. As soon as a sufficient quantity of yeast is purified in this manner transfer it to the washing vat and add three times its quantity of water. Then dissolve ounce of carbonate of ammonium in water to every quart of beer-yeast, and mix the solution with the yeast in the washing vat. The yeast soon separates as a white sediment on the bottom of the vat, while the hop-resin giving the bitter taste to the yeast remains dissolved in the water, which is then poured off. The white yeast remaining behind is now free from all bitter substances, but is not vigorous enough for the promotion of fermentation, and must therefore be subjected to a regenerating process. 3. Regeneration of the Yeast. Mash in crushed air-dry barley malt with cold water, heat the mash to 149° to 158° F., add ounce of tartaric acid to every 15 gallons of the mash, and let it stand in a room the temperature of which should not be below 721° F. for 24 hours, during which time the formation of sugar and acid takes place. Then free the mash from the grains by passing it through a fine hair-sieve, and add a half gallon of it to every quart of yeast to be regenerated. The temperature of the mixture should be 77° F. The mass will soon be thrown into vigorous fermentation, the revivified yeast rising partly to the surface, from which it is removed, and settling partly on the bottom. Fermentation ceases in about 36 to 48 hours; the fluid is then drawn off from the vat and the bottom yeast is mixed with the top yeast and both placed under water, and then pressed through double linen bags. The pressed yeast thus obtained is white, has no bitter taste, is very vig. orous and durable. Improvements in Treating Yeast. Brewers frequently suffer serious losses by the spoiling of the yeast in warm weather. The cause of the spoiling of the yeast must be sought, 1, in its porosity, as it is generally in a half liquid state, containing innumerable bubbles of carbonic acid which escape constantly, giving the oxygen of the air free access to all parts of the yeast, and, 2, in the rapid development of acid in the yeast, turning it sour and rendering it unfit for brewers' use. These evils may be overcome by the following treatment: Add three times the volume of the yeast of water of as low a temperature as possible to the vessels containing the yeast. Mix the yeast and water by stirring thoroughly, and then allow the yeast to settle for 24 hours. Then pour off the water, add half the quantity of fresh water, stir again, and add gradually milk of lime, a solution of soda or other alkali, until the fluid reacts only slightly acid. Then add to every 100 pounds of yeast about 14 ounces of salicylic acid. Allow the yeast to settle, and do not remove the supernatant fluid until the yeast is to be used. After drawing off the fluid add to every 100 pounds of yeast 10 pounds of a mixture of equal quantities of malt flour or wheat flour and sugar, and mix it thoroughly with the yeast. The yeast quickly absorbs this compound containing sugar and starch, which is at once recognized by an abundant development of carbonic acid. To render the yeast very active 8 ounces of a soluble phosphate may be added to every 200 pounds of yeast. Pressed Yeast from Beer-yeast. The following process gives, according to Pfauth, a pure and white yeast. Strain the yeast through a very fine filter in order to remove all larger resinous particles, and then stir it up with three times its quantity of cold water in a vat of suitable size and provided with cocks | the third water 1 ounce of carbonate of arranged at suitable distances one above ammonium. After the last water has the other. Allow the mixture to stand for 10 minutes for the yeast to settle, draw off the supernatant fluid, and repeat the washing twice. To the first wash-water add 14 ounces of bicarbonate of sodium to every 15 gallons of yeast, to the second ounce of tartaric acid to the same quantity of yeast, and to been drawn off the yeast is pressed into cakes. Some kinds of yeast settle with difficulty. In such cases, icecold water in larger quantities may be employed, or in lieu of this a little alum may be added to the first water, which must, however, be completely removed by washing. ADDENDA. ALLOYS. Alloy of Copper, Platinum, and Palladium. An excellent alloy of these three metals is made by melting for 3 hours 8 parts by weight of copper and 1 part of platinum with a pinch of borax. Then add 1 part of palladium and retain the crucible over a bright flame until the metals melt and amalgamate. Alloys Resembling Silver. In the following we give the composition of a few new alloys having the appearance of silver: Minargent: Copper 100, nickel 70, tungstate of iron 5, aluminium 1. Warne Metal: Tin 10, nickel 7, bismuth 7, cobalt 3. Trabak Metal: Tin 87.5, nickel 5.5, antimony 5, bismuth 2. and part of charcoal, is well adapted for the purpose. An addition of at the utmost 24 per cent. is sufficient, and the process is quite simple. After melting the bronze masses the metal bath is covered with pulverized charcoal and the pieces of cupro-manganese, previously weighed and comminuted, are allowed to slide slowly into the crucible; the melting together takes place immediately. The crucible must, however, be replaced upon the fire for a few minutes to restore the temperature lowered by the addition of the cold pieces of metal. Pouring out is done in the usual manner. To scorify the manganic oxide formed during the process add to the charcoal, with which the metal bath is covered, about one-half the quantity of pure sodium carbonate or potassium carbonate. The following alloys are prepared according to this process: Manganese Alloys. A good effect, as is well known, is produced by the use of manganese as an addition to bronze, brass, German silver, red copper, etc. All red copper and bronzes found in commerce contain more or less oxide, which injures their tenacity and malleability. The removal of the oxide is effected by substances having a greater affinity for oxygen than copper; for instance, by the addition of phosphorus in the form of a tin or copper phosphide, as in the preparation of phosphor bronze. nese, however, acts more energetically. An alloy of copper and manganese- 4. White brass 42 cupro-manganese-composed of 70.50 parts of copper, 25 parts of manganese, 1. 2. PARTS. 16 32 16 3 3 Manga 3. Red brass 14 17 or 20 ... A composition of 70 per cent. of | then exposed in a muffle 5 minutes to copper and 30 per cent. of manganese a temperature of 158° to 176° F. The is used as an addition to a large num- effect of this treatment is to render the ber of alloys, especially for red brass, surface of the iron or steel porous. white brass, and bronze. By this ad- With iron, not very good and coarsely dition the alloys acquire greater den- porous, the silvering process is diffisity, solidity, and ductility. A copper cult to execute. With steel, however, and tin alloy with 6 per cent. of man- the process easy; the article heated ganese possesses the hardness of steel. to about 140° F. is dipped in the alloy, We give in the following a few com- melted in a crucible over a moderate positions which can be highly recom- fire. The bath, which must be commended: pletely liquid, is stirred with a pine or poplar stick. The surface of the bath should show a fine silver white color. One to 2 minutes dipping suffices for a knife blade. When taken from the bath, the article is dipped in cold water, or, if necessary, hardened and tempered in the usual manner. It is then rubbed dry, and polished without heating. PARTS. 16 Copper. Tin. Zinc. Lead. Antimony. manganese. Cupro 10 16 9 2 Articles thus treated have the appearance of silver, and also possess the sound of silver, and resist oxidation in 11⁄2 the air. To protect them from the action of acid liquids they are first dipped in an amalgam bath of 69 parts of mercury, 39 parts of tin, and 1 of silver; then, while hot, in melted silver, and electroplated with silver. This method of silvering is claimed to be very durable and not costly. Manganese alloys can be polished, and their color is from white to rose color. In refining copper, cupro-manganese is used to reduce the cuprous oxide, playing a part corresponding to that of ferro-manganese in the manufacture of steel. Manganese silver composed of 80 per cent. of copper, 15 per cent. of manganese, and 5 per cent. of zinc is white, takes a good polish, and is easily worked. New Alloy for Silvering. This new alloy consists of 80 parts of tin, 18 of lead, and 2 of silver; or, 90 parts of tin, 9 of lead, and 1 of silver. Melt the tin, and when the bath is lustrous white add the granulated lead and stir the mixture with a pine stick; then add the silver and stir again. Increase the fire for a short time until the surface of the bath assumes a light yellow color, then stir thoroughly and cast the alloy into bars. The operation of silvering is executed as follows: The article-for instance, a knife blade-is dipped in a solution of hydrochloric or sulphuric acid, rinsed in clean water, dried, rubbed dry with a piece of soft leather or dry sponge, and Aluminium Bronze. Several alloys are known by this designation. By far the most useful and valuable is that composed of copper 90 per cent. and aluminium 10 per cent. It has a goldenyellow color, is very dense, and homogeneous. It may be worked hot or cold, though it is difficult to weld. It possesses great tensile strength, often as high as 100,000 pounds to the square inch, and is remarkably ductile and malleable. Its stiffness is 3 times that of gun bronze and 44 times that of brass. It can be cast very well and works well under the tool. It is generally acknowledged to be of all the bronzes decidedly the best. Recent improvements in the metallurgical treatment of aluminium promise to considerably lessen its cost, which, up to the present time, has stood in the way of its extensive use in the arts. (w.) Phosphor Bronze, which is largely used as a substitute for bronze and gunmetal compositions, for gearing, bear ings, wire rope, etc., etc., is an alloy of copper and tin which has been fluxed by the introduction of a variable quantity of phosphorus, which is generally added in the form of phosphide of copper or phosphide of tin. This addition prevents the formation of oxide by which the strength, ductility, and homogeneity of the resulting alloy would be impaired, and furnishes a metal which in respect to these qualities is notably superior to ordinary bronze. Numerous grades of phosphorbronze are made according to the uses for which it is intended. (W.) Manganese Bronze. This alloy is much used in England. It is formed by fusion of copper, tin, and manganese. Its color is usually white, and when very rich in copper tinged rose color. The addition of manganese to copper-tin alloys imparts to them greater strength, ductility, and homogeneity, resembling in this respect the influence of phosphorus. Thurston speaks very highly of this alloy as a material of construction. It is remarkably hard, tough, and elastic, as compared with ordinary bronze, and very durable when used for bearings of machinery. An average composition would have the proportions: Copper 88 per cent., tin 10 per cent., manganese 2 per cent. (W.) Fusibility of Alloys. In nearly all cases the fusibility of alloys is lower than the mean fusing point of their constituent metals. In some cases, as in that of the so-called fusible metals, the point of fusion is lower than that of either of their constituents. (W.) Spence's Metal. This compound has lately attracted considerable attention. It is an English invention, and is named after the inventor. Strictly speaking it is not a metal, but a compound obtained by dissolving metallic sulphides in molten sulphur, which is found to be capable of receiving into solution nearly all the sulphides of the metals. For most purposes Mr. Spence employs in the production of his "metal" the sulphides of iron, lead, and zinc, in varying proportions according to the quality of the product desired, which will depend on the uses for which it is designed. On cooling the mixture solidifies, forming a homogeneous, tenacious mass, having ordinarily a specific gravity of 3.37 to 3.7. It is said to be exceedingly useful in the laboratory for making the airtight connections between glass tubes by means of caoutchouc, and a water or mercury jacket, where rigidity is no disadvantage. The fusing point is so low that it may be run into the outer tube on to the caoutchouc, which it grips, on cooling, like a vise, and makes it perfectly tight. It melts at 320° F., expands on cooling, is claimed to be capable of resisting well the disintegrating action of the atmosphere, is attacked by but few acids, and by them but slowly; or by alkalies; is insoluble in water, and may receive a high polish; it makes clean, full castings, taking very perfect impressions; it is cheap, and easily worked. It has been used as a solder for gas-pipes, and as a Platinum and molyb-joint material in place of lead. (W.) Density of Alloys. This is frequently greater or less than the mean density of their constituent metals. In the following is given a list of alloys exhibit ing such abnormal densities: 1. Alloys exhibiting greater Density Gold and bismuth. Gold and antimony. Silver and zinc. Silver and tin Silver and antimony. denum. Palladium and bis- ized boracic acid; water vapor escapes during the operation. The manipulation of about 6 pounds requires an entire day, as on account of the viscosity of the melted mass it is difficult for the water vapor to escape. The process is completed when no more loss of weight takes place, and the preparation dissolves readily in water of ordinary temperature. The escaping water amounts to somewhat more than of the substances used. pregnating cotton for surgical purposes with boroglyceride. It is an excellent agent for preserving milk, fruits, meat, anatomical preparations, etc. Calcium and Sodium Glyceroborates, Two New Antiseptics. Both are readily soluble, odorless, and non-poisonous. Calcium glyceroborate is obtained by heating together equal parts by weight of calcium borate and glycerine with constant agitation, until a drop taken from the vessel and placed upon a glass plate solidifies to a clear colorless pearl. The compound is then poured upon a metal plate It is readily soluble in water, only where it solidifies to a transparent, slightly soluble in cold alcohol and in 5 glassy, and very brittle mass. parts of alcohol at 122° F., and insol- pieces, still hot, are kept in a welluble in ether and chloroform at or- stoppered bottle. Sodium glycerobodinary temperature. A hot alcoholic rate is obtained in the same manner by solution might be well adapted for im-heating together 100 parts of anhydrous Boroglyceride, when cold, is solid, brittle, and transparent, of a light yellow color and lustrous fracture. The |