This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1883 edition. Excerpt: ...the soap solution. This is also true of the dilution; but there is no free oil; this is probably what deceived Dr. Riley and Prof. Gillette. They saw this separation, and thought the liquid was not emulsified. Had they tested the diluted emulsion by putting a small piece of paper on top, and then touching the latter upon removal, with a lighted match, they would have quickly found that it was a perfect emulsion. The readiness with which it mixes, upon slight shaking, even years after preparation, is further proof. I have some in our museum made years ago, that is a perfect emulsion today. It is that pronounced against by Dr. Riley. One who has had much experience will be at no loss to distinguish a perfect emulsion as soon aB he adds water to dilute it. If there is free oil it will not mix; if not, it mixes very readily and with very slight agitation. Dr. Riley's emulsion thickens completely, looking like thick cream. This makes it hard to handle, especially in winter, as it must be dipped and cannot be turned from a vessel; but, more, the viscid mass hides the imperfection of the emulsion so that it does not appear till dilution takes place. The diluted emulsion also is more uniform upon standing, except that in all our experiments free kerosene rises to the top, which is less in case soft water is used. Again, my preparation is thoroughly emulsified so that upon any dilution, even with hard water, no free oil rises to the top. Thus it is easily mixed at all times, and may be kept in stock in a dilute or concentrated form for any period. Here again the match test shows that there is no free oil at the top. We have tried a very large number of cases, in all temperatures the past winter, and have not had a single failure. Dr. Riley's...