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sulphuric acid. He also discovered the fact that an overdose of the gas 

 was more liable to iujure the tree iu the hottest part of the day than it 

 would if used iu the cooler portion, and to remedy this he generated 

 carbonic acid gas with the hydrocyanic acid gas ; but later experiments 

 made by myself and others proved that this was only a partial preven- 

 tion. In accordance with the instructions of Professor Hilgard, Mr. 

 Morse used at first a pump, and later a fan-blower, for the purpose of 

 injecting the gas and also of stirring tt inside of the tent. 



In the latter half of the year 1887 I carried on another series of ex- 

 periments with hydrocyanic acid gas, using a tent constructed out of 

 common bedticking and oiled with linseed oil. I tken for the first time 

 tried the method of passing the gas through sulphuric acid, and found 

 that it was less liable to injure the trees than by either of the methodr 

 heretofore used. Shortly after the above facts were published, Mr. 

 Morse also tested this method and reported it as being the most 

 desirable method to use, but recommended using i^umice stone saturated 

 with sulphuric acid for passing the gas through, instead of using the 

 liquid acid. 



In the summer of 1888, I made another series of experiments with 

 this gas principally for the purpose of testing the different brands of 

 potassium cyanide found in the market of Los Angeles, and found 

 tjfaat the cyanide manufactured by Powers & Weightman, of Phila- 

 delphia, Pennsylvania, was nearest of a uniform strength, and gave 

 the best results. 



In the month of September, 1889, 1 carried on another series of exper- 

 ments with this gas, using a tent belonging to Mr. A. D. Bishop, of 

 Orange, California. This tent was made out of blue denims, and before 

 commencing the experiments I had it painted black. All of these 

 experiments were made in the daytime, from 9:30 a. m. to 5:30 p. m., and 

 I found that by using the cyanide dry, along with two parts of water 

 to every one of sulphuric acid, and dispensing altogether with the 

 machinery for circulating the gas in the tent, better results were obtained 

 than by the use of either of the methods described above, while at the 

 same time the process was much simpler and cheaper than these. 



After ascertaining the results of these experiments I gave the formula 

 to Mr. A. H. Alward and Mr. A. D. Bishop, and also informed them of 

 the other facts relating to this process, and stated that better results 

 would be obtained by the use of the gas at night than would be by 

 using it in the daytime. Accordingly Mr. Bishop tested this process 

 at night, and finding that it gave such good results he, in conjunc- 

 tion with Drs. W. B. Wall and M. S. Jones, of Tustin City, California, 

 applied for a patent on this process. As soon as I learned that a patent 

 had been applied for I at once wrote to Professor Riley on the subject, 

 and he laid the matter before Assistant Secretary of Agriculture 

 Wlllits, who wrote to the Commissioner of Patents, protesting against 

 the issuing of a patent on the gas treatment to the above mentioned 



