THE URINE 167 



useless. The dose should vary from 25 to 250 millions, or 

 even more; some cases do well on very minute doses (i to 5 

 millions), frequently repeated. The effect seems to be in- 

 creased by rendering the urine slightly alkaline by means of 

 citrate or acetate of soda. 



Proteus Vulgaris. This is one of the common organisms 

 of suppuration of the urinary tract, and produces cystitis with 

 an alkaline urine. It often occurs in conjunction with B. coli, 

 and the urine is alkaline in this case also, the proteus being 

 more powerful as a producer of alkali (by the ammoniacal 

 decomposition of urea) than the B. coll is of acid. 



It closely resembles B. coli in appearance, and is motile; the 

 chief points of difference are that it is more irregular in size 

 and forms longer threads, and that some of the bacilli often 

 fail to decolorize by Gram. In cases where the two organ- 

 isms are present it is impossible to distinguish the one from 

 the other, either in a hanging drop or in stained films. 



If it is necessary to know whether B. coli or B. iyphosus is 

 present along with Proteus vulgaris in an ammoniacal urine, 

 the simplest method is to plate out some of the urine on 

 gelatin (see p. 148), making several plates with different dilu- 

 tions; as a rule, a minute trace of the urine is all that is neces- 

 sary. Typhoid and coli form small, semi-translucent, greyish 

 colonies which do not tend to spread very much, whilst proteus 

 forms small grey colonies which form radiating branches 

 which spread with great rapidity. They liquefy the g'elatin, 

 forming a saucer-like excavation with a white mass of growth 

 in the centre. Or the methods described under the heading 

 of typhoid fever may be used. 



Streptococci occur occasionally as independent causes of 

 pyelitis or cystitis, and in these cases I believe the prognosis 

 to be somewhat worse than in the other forms. 



Staphylo cocci usually occur as a secondary infection of 

 other forms of cystitis. The M. urea is a frequent cause of 

 ammoniacal decomposition of the urine, and is often mis- 

 taken for a staphylococcus ; the two are indistinguishable 

 under the microscope, but staphylococci liquefy gelatin 

 rapidly and M. urea; does so slowly. Their separation is of 

 no clinical importance in these cases. 



The M. urea? appears to be identical with the common skin- 

 coccus, which is the most common and characteristic organ- 



