With regard to the question as to whether experimental dyeing with bichromate of potash should be employed as a test even in works where all the dyeing was done with other mordants, he was decidedly of opinion that it should always be resorted to as one of the tests, inasmuch as it was the only simple and expeditious method giving a fair idea of the actual wood strength and money value of the extract. The test should, in such cases, be supplemented by dyeing trials with the mordants used at the works, and, if necessary, also by a chemical analysis. Printing trials were not necessarily bad tests, since oxidizing was usually added in these where it was necessary, and any undeveloped coloring matter would thus be oxidized during the steaming process: but, as he had stated before, it was essentially necessary in such cases to have a fair idea of the amount of actual coloring matter in the extract and to adjust the proportion of mordant accordingly. Such trials should therefore be preceded by carefully conducted dyeing trials with bichromate of potash. Mr. Thomson had raised the question whether it would not be well for the manufacturer to prepare these extracts in such a manner that they would contain all the coloring matter in one condition only, in order to insure greater uniformity in their quality and mode of application. This would, no doubt, be a desirable step to take if the owners of dye and print works were more in the habit of availing themselves of the service of competent chemists experienced in this branch, for then they would be able to make any extract do its full work irrespective of the state of development of the coloring matter. Such, however, was not the case, and it was a very common thing for the consumer of dyewood extracts to require the manufacturer to prepare them specially for him so as to suit his own dyeing recipes, or in other words to give exactly the same shades, weight for weight, by his own method of dyeing as the article he was in the habit of using. The manufacturer was thus often compelled to make many different qualities of the same extract to suit different customers. For the same reason adulterated articles were often preferred to the pure ones. There was, perhaps, no branch of industry in which chemical skill of a high order could be applied with greater advantage than in dyeing, and nowhere was this fact less recognized. Some of the processes of dyeing were exceedingly wasteful and stood in much need of improvement. He (Mr. Siebold) knew a large works in which a ton of logwood extract was used daily for black dyeing only, and he might safely assert that of this enormous quantity only a very small proportion would be fixed on the fiber, while by far the greater proportion was utterly wasted. Such a waste could only be prevented by a searching investigation of its causes by trained skill. Mr. Thomson had further alluded to the color obtained with logwood or