BUREAU OF ANIMAL INDUSTRY. 121 



Most of the remedies tried failed to show a high degree of efficacy. 

 Gasoline, commonly recommended for the treatment of sheep affected 

 with stomach worms, given in repeated doses, had very little effect 

 npon these parasites. It is possible that the difference between the 

 gasoline of the present time and the higher grade of 15 years or more 

 ago, when it first came into use for treating sheep to destroy stomach 

 worms, would explain recent failures. In fact, it was found that 

 petroleum benzin, which is very similar to the gasoline of a few years 

 ago, gave better results. Copper-sulphate solution, however, seems 

 preferable as a stomach-worm remedy; it is more easily administered, 

 is cheaper, and is highly efficacious even in a single dose. Gasoline 

 as formerly used was customarily given in three doses at intervals of 

 24 hours, mixed with milk, so that it was a very troublesome and 

 rather expensive remedy to use. Chopped tobacco stems soaked in 

 water and mixed with the feed, as recommended by Herms and 

 Beach, of California, have given good results as a remedy for certain 

 nematodes which commonly affect poultry. Oil of chenopodium has 

 continued to give good results as a remedy for intestinal roundworms 

 of hogs. tI!hloroform has proved to be a very efficacious remedy for 

 hookworms in dogs, but experiments have indicated that it is not satis- 

 factory for hookworms in sheep, because of its injurious effects on 

 the sheep. 



BLACKHEAD OF TURKEYS. 



Investigations on blackhead in turkeys have been continued, but 

 owing to difficulties encountered in obtaining suitable material and 

 the small number of birds available for experimental purposes very 

 little progress has been made. 



COLLECTION OF PARASITES. 



Several hundred specimens of parasites from the United States 

 and abroad were added to the reference collection maintained by 

 this division. 



ZOOLOGICAL INVESTIGATIONS RELATING TO MEAT INSPECTION. 



In continuation of the investigations on the effects of the curing 

 process upon the vitality of trichinae, repeated tests have been made 

 of the methods permitted by the bureau for the preparation of pork 

 products customarily eaten without cooking. In these tests no case 

 has occurred of the survival of trichinae in trichinous pork prepared 

 following the methods permitted for such products. Other methods 

 have also been tested, with favorable results, but the data collected 

 have not been considered sufficient to justify their acceptance as 

 adequate for the destruction of the parasites. 



The results of former experiments have been confirmed by further 

 investigations upon the effects of heat on trichinae. The larval para- 

 sites die at 55° C. if the temperature is gradually raised to this point, 

 and temperatures somewhat lower are fatal if maintained long 

 enough. 



Experiments on the effects of X rays have shown that trichinae 

 may be destroyed by massive applications of the rays, but whether 

 the use of X rays can be made commercially practicable for the 

 sterilization of trichinous pork has not yet been determined. 



