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meetings of this association that a good fish-oil soap should not con- 

 tain more than 10 to 15 per cent of water for the hard soaps, and from 

 25 to 30 per cent for the soft soaps, and that many of the formulas 

 which purported to produce a very cheap soap merely meant a soap 

 swelled to great weight and volume by the very large water content. 



The greatest objection to most of the soaps on the market, as often 

 pointed out, is that when dissolved in water at the great strength now 

 employed, a gelatinous mixture results on cooling, which is very diffi- 

 cult or impossible to spray except at high temperatures difficult to 

 maintain in winter work. The source of this objectionable feature was 

 first supposed to be in the use of the cheaper caustic soda instead of 

 the more expensive caustic potash, the former making a hard soap not 

 readily dissolved in water, and the latter a soft soap and one much 

 more easily soluble. 



The possibility that the hard gelatinous quality of certain soaps was 

 due to the use of tallows and other refuse fats, strong in stearin, was 

 also suggested. Examinations and analyses of many different brands 

 of soaps indicated that the difficulty was not entirely explained by the 

 first of these suppositions, showing as they did in the first place that 

 practically all the fish oil soaps on the market were made with caustic 

 soda, and in the second place that a caustic soda soap did not neces- 

 sarily present the objectionable feature noted. The second of these 

 suppositions, namely, that the use of waste tallows and fats of that 

 character had something to do with the gelatinizing of soaps in solu- 

 tion, was shown to have some basis in fact, but did not explain the 

 difficulty in all cases. 



In examining the process of soap making it seemed that the addi- 

 tion of salt might have some effect in producing a soap which would 

 behave properly in solution, and further, that the addition of lime might 

 have a similar influence. The tests made with salt showed that this 

 substance exerted no effect on the behavior of soap. With lime, on the 

 other hand, it was found that its addition to the soap in solution in 

 sufficient quantity would break it up, so that it would remain of a fluid 

 consistency even when chilled. A true fluid, however, \/as not obtained, 

 but a granular substance caused by the lime precipitate, such as is seen 

 in the use of soap with hard water. 



The cause of the marked gelatinizing of soaps in solution was still 

 far from being satisfactorily explained. What is probably a very fre- 

 quent if not the usual cause of this difficulty has, I think, now been 

 determined. 



It seems that soap makers in the East very frequently cheapen their 

 washing soaps by the addition of silicate of soda, a gelatinous sub- 

 stance costing only about a cent a pound, and, perhaps, not working 

 any serious mischief to the soap for washing purposes, but for all insec- 

 ticide uses rendering it comparatively valueless. 

 7184— No. 17 7 



