Confectioners employ several colours. Yellow, brown and black are usually obtained by means of caramel; the other colours, red, green and blue, which are also largely used, must be made from harmless compounds. Unfortunately, colour makers have been known to offer the consumer for this purpose colours which by no means correspond to this requirement; even the poisonous arsenic pigments have been used for colouring sweets. In such a case the user of the colours is less to be blamed than the manufacturer, who should sell for this purpose only colours in no way injurious to health. Fortunately we possess among the pigments of organic origin a sufficient number to satisfy these requirements: for green, either sap green or leaf green may be used without hesitation; for red, cochineal carmine is well suited, and for blue, indigo carmine. The two pigments last named are indeed expensive, but since they possess great colouring power they can still be used for colouring cheap sweets. For colouring liqueurs equal care must be taken to choose non-injurious colours. Those mentioned above may also be used for this purpose. Recently these colours have been largely displaced by the aniline dyes, which are particularly adapted by their beauty and great colouring power for the colouring of confectionery or liqueurs. There should be some hesitation in using these dyes for colouring articles of food. Some of them are made by means of arsenic compounds, and it is very difficult to free them absolutely from every trace of arsenic. But supposing the dye to be free from arsenic, there may still be objections to its use, for the pure dyes themselves may possess poisonous properties, and thus ought not to be used for colouring articles of food. For colouring foods the colours above mentioned are sufficient. Orange is obtained by mixing caramel with red, violet by mixing red and blue, and the shades thus produced are quite sufficient for the purpose in question. The colour maker should sell the colours in such a condition that they can be used without further preparation. The colours for confectioners and liqueur makers should be put on the market in a semi-fluid or pasty condition. For this purpose carmine should be ground with a very thick sugar syrup. Leaf green and indigo carmine require no further preparation; they are already semi-fluid, they readily diffuse, and are also soluble in alcoholic liquids. CHAPTER LXIX. THE PREPARATION OF PIGMENTS FOR PAINTING. According to the purpose for which they are to be used pigments require a different method of preparation. The preparation of pigments for certain special purposes, such as sap colours, cake colours and water colours, has been already described. The present chapter deals with the preparation of those pigments which are used in large quantities by artists and for ordinary painting.