Potash not only is a more expensive alkali, but its combining equivalent is greatly against it as compared with soda; that is to say, that thirty-one parts of actual or anhydrous soda will saponify as much tallow or oil as forty-seven parts of anhydrous potash. It will be evident, therefore, that the use of potash instead of soda is decidedly more advantageous to the soapboiler, and more particularly in the present age, when the demand is for cheap articles, often quite without regard to the quality or purpose for which they are to be used. As far as consumers are concerned, this has been a mistake. Potash soap, though it may cost more, is in most cases actually the most economical. Soap is never used in exact chemical equivalents, but an excess is always taken. Potash soap is much more soluble than a soda soap; it therefore penetrates the fiber, and consequently removes dirt and grease much more quickly. Notwithstanding, also, that its chemical combining equivalent is greater than that of soda, it is, nevertheless, the strongest base, and always combines with any substance in preference to soda. For these reasons--probably combined also with the fact that in the whole realm of the animal and vegetable kingdoms, to which all textile fabrics belong, potash is more naturally assimilated than soda--a smaller quantity of potash soap will do more practical work than a larger quantity of soda soap. There are other reasons why potash soaps have not been used; originally soft soap was made either with fish oil or olive oil. Fish oil is objectionable, as the strong smell imparted to the soap renders it unfit for many finishing purposes. Nothing can be better than olive oil soap, but it is a costly article, and only can be used for finer purposes. There are now, however, many of the seed oils that are much cheaper. Linseed, rape seed, and cotton seed all produce a good soap. Cotton seed oil is particularly suitable for the purpose; the manufacture of this oil during the last few years has been brought to great perfection, and the cost is now much less than that of tallow or of any other seed oil. It is now difficult to distinguish a well refined cotton seed oil from olive oil; it is therefore in every way suitable for making soft soap. One of the chief causes, however, why potash soap has not been more generally made is that a convenient form of potash has been unobtainable. For many years the only source of potash was from the ashes of burnt trees. These ashes are collected, mixed with lime, lixiviated, and the resulting lye boiled down. The result is a very impure form of potash, also of a very variable composition, depending upon the trees used for the purpose. Canada has been the principal source of supply of this form of potash; hence the commercial name of Montreal potashes. The classification of "firsts," "seconds," and "thirds" is from the inspection at the warehouse there; this, however,