Crayons, Yellow. From king’s yellow, Naples yellow, orpiment, yellow ochre, &c.
Crayons, Lithograph′ic. Prep. 1. Tallow-soap, 7 parts; white wax, 6 parts; melt by a gentle heat, and add lamp-black, 1 part; keep it melted with constant stirring, for 20 or 30 minutes, then let it cool a little, and cast it into moulds.
2. White wax, 4 parts; shell-lac and hard tallow-soap, of each 2 parts; lamp-black, 1 part; as last.
3. Spermaceti, white wax, and hard tallow-soap, of each equal parts; lamp-black, q. s. to colour.
Obs. Some makers melt the soap, wax, and lamp-black in an iron ladle, over a brisk fire, and allow the mixture to blaze for a few seconds before adding the shell-lac, which is no sooner thoroughly incorporated than the heat is increased until the mass again kindles, when it is at once removed from the fire and stirred until it is cool enough to be poured into the moulds. This method leads to trouble and loss, without any corresponding advantage. These crayons are used to draw designs upon lithographic stones.
Crayons for Writing on Glass. Prep. 1. From French chalk, cut into suitable pieces. Marks made with these crayons, when obscured or rubbed out, may be several times revived by simply breathing on the glass.
2. (Brunquelle.) Spermaceti, 4 parts, tallow, 3 parts, wax, 2 parts, are melted together in a cup; and red lead, 6 parts, and carbonate of potassa (in fine powder), 1 part, stirred in; the mass is kept melted and stirred for about half an hour longer, then poured into glass moulds (tubes) of the thickness of a common pencil, and cooled as rapidly as possible. The mass may be screwed up and down in the tube, and cut to a point with a knife. A crayon is thus obtained which will readily write upon clean, dry glass.
CREAM. Syn. Crem′or, C. lac′tis, Flos lac′tis, L. The oleaginous portion of milk, which collects in a thin stratum upon the surface, when that fluid is left undisturbed for some time. By violent agitation, as in the process of churning, the fatty globules unite together, forming butter; whilst the liquid portion, consisting of caseum, serum, and a little butter, constituting the residuum, is called butter-milk. This separation is effected the most readily when the cream has become partially sour and coagulated by being kept a few days, a change which occurs in consequence of the conversion of some of the sugar of the serum into lactic acid, which precipitates the caseous matter contained in the small portion of the milk with which the
cream is mixed. On these simple facts chiefly depend the successful manufacture of butter. The cream intended for churning should therefore be kept until it turns slightly sour, and assumes the condition above referred to, as then the butter will readily ‘come.’ If churned while quite sweet the operation will be tedious, and will frequently fail. When this happens the dairy maids declare the milk is ‘charmed’ or ‘bewitched,’ and reluctantly proceed with the operation. The addition of a little rennet or vinegar is the proper remedy in this case, and will cause the almost immediate separation of the butter.
When cream is suspended in a linen bag, and allowed to drain, it gradually becomes drier and harder, by the separation of the liquid portion, and then forms what is known by the name of cream cheese. By the application of slight pressure the separation of the whey is more completely effected, and the product is not only better, but will keep longer.