(5) Shellac 4 parts Wax 8 parts Soap 5 parts Lampblack 3 parts The shellac is to be completely dissolved with the wax by means of combustion after which the rest of the treatment is the same as before. (6) Shellac 4 parts Wax 8 parts Tallow 2 parts Soap 5 parts Lampblack 3 parts The same treatment, except that the tallow is to be mixed in after the shellac has dissolved. This crayon is a little softer than the others. The same is true of the following two. (7) Wax 8 parts Tallow 4 parts Soap 6 parts Lampblack 3 parts Wax, tallow, and soap are melted together and burned till one third of the mass has been consumed. Then the lampblack is added and the rest of the process is as before. (8) Wax 2 parts Tallow 6 parts Mennig 2 parts Lampblack 2 parts Wax, mennig, and lampblack are heated and constantly stirred till the mennig dissolves in froth and changes from red to brown. Then the lampblack is rubbed in thoroughly, the whole warmed again properly and shaped into sticks. These are the best compositions, thoroughly tested by me, and it is very good to make a stock of all or most of them. In the case of the recipes for chemical ink, the differences are not great, and it is largely a matter of taste as to which kind one may use. But in the case of the crayons, each of them produces a different grain which creates a particular effect; so that by using various kinds of crayon one will gain greater perfection of work, or, at least, find execution easier than with only one crayon. Also, they are in proportion to the greater or lesser roughness of the stones; and the darker shadings are easier to produce with soft crayons than with hard ones, while the hard ones are best for fine shading and outlines. The lampblack used for crayons must be burned out first, else it will develop blisters, which is the case also if the composition is poured on the plates too hot. Crayon that contains much shellac is likely to soften in damp air; therefore it should be kept in tightly closed vessels. IX CONCERNING COLOR FOR PRINTING The manufacture of printing-ink or color is very difficult and dangerous on a large scale. I counsel all to take lessons from a book printer when he makes it. The varnish must be prepared in the open, far from buildings, because of its combustibility. The best utensils and skilled workmen are required, because otherwise terrible accidents may occur, and even life be lost through explosion of the copper receptacle. Whoever does not require as much as one or more hundredweight of varnish in a year, would better buy it from printers or make only a small quantity, one or two pounds, and in an open vessel. For this purpose I will describe the process.