312 VETERINARY BACTERIOLOGY 



Smith has given excellent results in the hands of numerous in- 

 vestigators. A dog is bled, using all aseptic precautions, from the 

 femoral artery into a sterile vessel and the blood allowed to clot. 

 The serum is removed by sterile pipettes to sterile test-tubes. 

 These are slanted and heated to a temperature of 75 to 76 for 

 about three hours, or until the serum is coagulated. The heating 

 must be done in a saturated atmosphere and the medium stored so 

 that there is no loss by evaporation. Bits of infected tissue are 

 placed upon the surface and kept in a thermostat for several weeks. 

 If no growth appears, the tissue is moved about and incubated 

 again. A constant temperature of 37 and a saturated atmosphere 

 must be maintained. 



A procedure somewhat simpler than the preceding has been 

 described by Dorset and is found to give good" results. The shell 

 of fresh eggs is carefully broken, and the white and yolk dropped 

 into a sterile flask, the yolk broken with a sterile rod or wire, and 

 the contents of the flask shaken until the two are thoroughly mixed. 

 Foaming is to be avoided. The mixture is placed in tubes, slanted, 

 and heated at a temperature of about 70 for from four to five hours 

 on two days. This coagulates and sterilizes the medium. The 

 tubes should be stored where they will not lose water by evapora- 

 tion. Several drops of distilled sterile water should be added to a 

 tube just before incubation. The isolation upon this medium is 

 carried out as outlined above. A growth may generally be ob- 

 served within ten days after inoculation with fresh tissue. 



Isolations from sputum or feces, milk, or other substances in 

 which the organisms occur mixed with other forms, is attended with 

 some difficulty. It is usually accomplished by injecting the mate- 

 rial or the sediment yielded by centrifugation directly into a guinea- 

 pig. The bacilli may later be isolated in pure culture from the 

 nodules produced. Within recent years the use of " antiformin " 

 and similar substances has considerably simplified this procedure. 

 Antiformin is the trade-name given a disinfectant mixture having 

 the following composition: 



Solution I. Sodium carbonate 12 gm. 



Chlorinated limo 8 RMI. 



Distilled water SO gin. 



Solution II. Sodium hydroxid 15 gm. 



Distilled water 85 gm. 



