18 BULLETIN 131, U. S. DEPARTMENT OF AGRICULTURE. 



such quantities as it is economical to use the action lasts less than 

 a day when cottonseed oil is used, and about two days when Beau- 

 mont oil is used. As shown by the third test, 50 per cent oil of tar 

 is dangerous when applied in large quantities. 



The last test shows that 50 per cent oil of tar in Beaumont oil 

 when applied in small quantities with a brush is also dangerous. 

 The increase of the content of oil of tar from 10 to 50 per cent does 

 not seem to increase the duration of the repellent action materially, 

 as indicated by tests 1 and 3, but the 50 per cent Beaumont oil mix- 

 ture protected twice as long as the 10 per cent mixture. 



For the purpose of determining whether daily applications of 10 

 per cent oil of tar in cottonseed oil would produce poisoning or other 

 untoward results, a calf was treated with the mixture on October -2, 

 3, 4, 6, 7, 8, 9, 10, 11, 13, and 14. The mixture was applied with a 

 paint brush. No symptoms of poisoning resulted, and the skin 

 remained unaffected. 



THE MOORE FORMULA. 



October 4, 1912, a calf was sprayed with the following mixture: 



Fish oil 100 parts. 



Oil of tar 50 parts. 



Crude carbolic acid 1 part. 



About three quarts of the mixture were used. The animal appeared 

 sick after being sprayed. It was restless and there was salivation. 



October 7, the animal was very oily. There was present an odor 

 of tar and fish oil. Flies were still repelled. 



July 16, 1913, a bull calf was treated with the above mixture, which 

 was applied with a brush, and 6 ounces were used. The repellent 

 action was marked. There were no symptoms of poisoning. 



It is noted from the first of the above tests that the application of 

 the Moore mixture in large quantities is dangerous. Such a liberal 

 application, however, would never be made in practice. The repel- 

 lent action was still evident on the third day. In the second test a 

 small quantity of the mixture was applied to a calf by means of a 

 brush and no symptoms of poisoning resulted. 



TEN PER CENT OIL OF CITRONELLA IN COTTONSEED OIL. 



June 19, 1913, a calf was treated with 10 per cent oil of citronella 

 in cottonseed oil, applied with an atomizer. A few hours later all 

 protection had ceased. 



July 2, 1913, the above calf was again sprayed. An hour or so 

 later a repellent action was still noticeable. The calf was not trou- 

 bled much with flies as compared with the untreated animals. 



July 3, 1913, a cow was sprayed. Used 1£ ounces. There was a 

 very marked repellent action, but an hour or so later this had become 



