ANALYSIS OF OCHRE.
Below is an analysis of a sample of French ochre, which is about the average of that pigment:
| Parts. | |
| Hydrated oxide of iron | 42 |
| Alumina | 20 |
| Silica | 38 |
The oxide gives the color; the parts as given above are in the right proportion to give the most stable color and durable body to be found in ochre.
Here is an ochre, which was ground in a linseed oil substitute, and sold to the trade at four cents per pound in twenty-five pound cans, and retailed to the painter at seven cents per pound in cans, to-wit:
| Parts. | |
| Barytes | 58 |
| Whiting | 15 |
| Oxide of iron, silicate and alumina | 24½ |
| Chrome yellow | 2½ |
This so-called ochre could be ground in one-half the oil it would take to grind yellow ochre.