56 



ance. This can be overcome by adding a handful of commo i 

 salt and about half a teacupful of lard to each gallon of the wash, 

 which should then be thoroughly stirred before ' being applied. 

 One of my California correspondents, in a letter dated Augunt 

 27, 1895, says: "When making the Avhitewash I put in all the 

 sulphuric acid that can be used without burning the pipe through 

 which the wash is sprayed on the walls. I believe this acid is a 

 good thing." 



Sulphuric Acid. — A strong solution of sulphuric acid has been 

 used to wash machinery, elevators, and spouts with good results, 

 the acid being afterwards washed off with water. 



Tobacco. — The burning oE tobacco in mills is not effective on a 

 large scale, but has given fairly good results in small, tight room& 

 and bins. Tobacco infusion has also been used for washing and 

 cleansing apparatus, but, on the whole, it is not a satisfactory 

 substance for general use. 



Flour Paste. — The value of this material is summed up in the 

 following letter from one of my California correspondents: 'To 

 answer to your question, 'What led you to try the flour paste ex- 

 periment? 1 would state that we use Hour paste for putting up 

 packages of small good?. This paste is made, as needed, by one 

 of our workmen, and is composed of flour, water, and vinegar, 

 and is boiled by steam. I pay particular attention, in a general 

 way, to all the work going on in the mill, visiting it every morn- 

 ing and going through every department. On one or two morn- 

 ings I noticed that during the night the moths had seemed to 

 congregate about this paste, many of them having fallen into it, 

 and as it is of a tenacious nature they could not get away, and 

 had perished. This seemed to be a curious kind of a thing to 

 me and I made some investigation — had some of the paste put 

 out in shallow pans, and I discovered that it had an attraction 

 for the moth. I found, however, that it must be in a certain 

 stage of fermentation in order to be of any value as an extermi- 

 nator. I then commenced a series of experiments on a large 

 scale, and in a short time had so reduced the number of moths 

 in the mill that I was very much delighted with the result. At 

 the same time I • carried on experiments with other materials, 

 the cost of the paste being a considerable item, since it had to 

 be renewed every few days in order to be of any service." 



Vinegar and Water. — This experiment was suggested by the 

 one immediately preceding, and is outlined by the same miller in 

 a letter dated August 23, 1895, which I quote in full: "I have 

 tried numerous ways of getting rid of the pest, and, if I remem- 

 ber rightly, when I saw you last I was experimenting with flour 

 paste. My experiments in that direction gave some promise of 

 success, but I eventually abandoned the flour paste for a mixture 

 of vinegar and water^ — about one fourth vinegar to three fourths 

 water. This seemed to attract them as much as the paste did, 

 and was not nearly so inconvenient, for the pans did not need to 



