ITS PEACTICAL VALUE TO THE GENERAL PRACTITIONER. 15 



from the typhoid bacillus, but their practical diagnostic value can 

 hardly compare with the simple method of serum diagnosis. Cul- 

 tures, at present, are of chief value to the practitioner in diagnos- 

 ing diphtheria, and those who have not the advantage of a labora- 

 tory may procure the necessary media,, and with a little training 

 make their own examinations. In lieu of an incubator the inocu- 

 lated tube, in a protecting case, may be carried in an inner pocket, 

 the body supplying the necessary warmth. 



Animal inoculations have proven useful in diagnosing genito- 

 urinary tuberculosis in cases where the bacilli were not shown by 

 staining. Some of the fresh urinary sediment (obtainable from a 

 single kidney by the ureteral catheter) is injected into the ab- 

 dominal wall of a guinea pig that is killed after five weeks and 

 examined for tuberculous lesions. Animal inoculations are also 

 of value in diagnosing the type of many of the infections ; while 

 the subdural inoculation, in a rabbit, of a bit of the spinal cord of 

 the affected animal remains the best method of ascertaining the 

 existence of rabies. 



One of the greatest advances in bacteriologic diagnosis is that 

 dependent upon the tendency of the bacteria of >a given disease to 

 agglutinate, or collect in clumps, and to lose their motility when 

 brought in contact with the serum from a person affected by the 

 disease. Although this method is useful in determining the 

 variety of the bacteria, the presence of infective organisms in 

 drinking water, etc., its greatest value has been in diagnosing 

 disease. 



Being present in over ninety-five per cent, of cases of ty- 

 phoid, it is the most useful diagnostic sign yet discovered. The 



