39 



received for experimental purposes from William H. Pinner, of New 

 York City, and James Good, of Philadelphia, and we have had a num- 

 ber of proprietary insecticide soaps, testing also some common brands 

 of washing soaps for purposes of comparison. 



Assuming that one has received a brand of fish-oil soap from an 

 honest manufacturer, to be satisfactory for insecticide use it must when 

 dissolved at the desired rate, say 2 pounds to the gallon of water, 

 remain a liquid capable of being sprayed with an ordinary nozzle at 

 an ordinary temperature. The presence of water in the soap, which is 

 a most variable quantity, should also be approximately known to enable 

 one to determine the amount of soap to use to make a correspondence 

 with the standard of strength. 



The experiments with soap have been in the direction of testing, 

 therefore, first, the physical properties, viz, when dissolved if it would 

 remain in liquid form; second, the percentage of water in the soap, and 

 third, the constituent elements of the soap, so far as could be deter- 

 mined by chemical and other tests. 



The first proposition, whether the soap would remain liquid when dis- 

 solved at the strength employed, may be determined by a very simple 

 test and one which should be invariably given any soap before it is 

 accepted for spraying operations. It consists in simply dissolving a 

 small quantity of the soap at the desired rate and allowing it to cool. 

 Some 18 soaps were subjected to this test, dissolving them at the rate 

 of 2 pounds to the gallon. Nine of these stood the test satisfactorily, 

 remaining liquid even when subjected to low temperatures in a refrig- 

 erator, and nine solidified or became gelatinous and tenacious at high 

 summer temperatures. All but two of these soaps were especially 

 manufactured for insecticide purposes. Among the soaps sustaining 

 satisfactorily the solution test were the old whale-oil soap (Leggett 

 Bros.) ; three of the Pinner brands, including his concentrated chemical 

 soap; a light-colored fish-oil soap made by Good, and a potash soap 

 made by the same manufacturer, at my earnest request several times 

 repeated. The other soaps proving satisfactory in this respect are fir- 

 tree oil soap (Stott's), tobacco soap (Rose & Co.), and a soap made at the 

 United States Department of Agriculture with potash. Some of these 

 soaps were very hard, as the Leggett whale oil, Pinner's concentrated 

 chemical, and the light-colored soap made by Good. The rest were 

 not so hard, and Good's potash soap was almost a soft soap, although 

 the water percentage in it was not very much greater than some of the 

 hard soaps. 



Among the soaps resulting in a gelatinous or nonfluid mass with the 

 solution test were three of the lots of alleged fish-oil soap submitted 

 by Good at different dates ; the Pinner chemical tobacco soap; another 

 tobacco soap, manufacturer unknown, and two washing soaps, the 

 "Star" and "Babbitt." One of the soaps made by Good (Xo. 6) was 

 dissolved at the rate of 8 pounds to the gallon and dried down to a 



