REPELLENTS FOR PROTECTING ANIMALS FROM FLIES. 15 



FIFTY PER CENT PINE TAR IN BEAUMONT OIL. 



August 19, a cow was treated with 50 per cent pine tar in Beau- 

 mont oil. The mixture was applied with a brush. 



August 20, the mixture had been rubbed off the sides and abdo- 

 men. The odor of tar was still present. The hair was rather untidy. 

 Flies were present only on underside of abdomen. 



August 21, the cow was stiff. The mixture ay as still present on the 

 back. There was no repellent action. 



SUMMARY OF RESULTS WITH PINE TAR. 



It is noted from the first test made that a liberal application of 

 10 per cent pine tar in cottonseed oil caused the animal to look 

 droopy. It is probable that this was due to a toxic action of the tar. 

 The odor of the tar had disappeared on the second day following the 

 treatment. The repellent action lasted for three days. Some oil 

 was present five days after the treatment. 



In the test in which 20 per cent of pine tar was used, the mixture 

 was applied with a brush and only 5J ounces were used. The repel- 

 lent action was marked, but not so great as in the case of 10 per 

 cent crude carbolic acid or 10 per cent oil of tar. The repellent ac- 

 tion lasted less than 18 hours. The odor of tar had disappeared at 

 that time. 



In the third test in which a half-and-half mixture of pine tar and 

 cottonseed oil was used, the mixture was applied liberally by means 

 of a spray pump. The repellent action lasted more than three days 

 in the case of both animals treated. The mixture is too thick to be 

 used in a spray pump. 



In the last test, in which a half-and-half mixture of pine tar and 

 Beaumont oil was used, the repellent action lasted less than two 

 days. This mixture had a detrimental effect in that it caused the 

 animal to become stiff. 



There seems to be no danger to animals in applying tar in cotton- 

 seed oil for the purpose of repelling flies. In the first test there 

 were slight symptoms of poisoning, but the amount of 10 per cent 

 mixture applied (3J quarts) was much more than would ever be 

 applied to an animal to protect it from flies. 



It is evident from the second test that when a pine-tar-cottonseed- 

 oil mixture of moderate strength is applied in quantities such as it 

 is economical to use, the applications will have to be made every day 

 in order to provide protection. 



