EXAMINATION OF THE BLOOD. 169 
The practitioner is recommended to practice this 
method of staining, as it does not require any reagents 
which are not to be found in every well stocked surgery. 
The watery solution of methylene blue which is used as 
a counterstain for the tubercle bacillus and some red ink 
are all that are necessary. 
THE BACTERIOLOGICAL EXAMINATION 
OF THE BLOOD. 
The bacteriological examination of the blood is not of 
very great diagnostic importance, as it is only in a very 
few diseases that pathogenic bacteria are present in the 
circulation in such quantities as renders the search for 
them in the minute amounts which are withdrawn for 
examination at all promising. 
The chief organisms which have been found in the 
blood are :— 
1 & 2. Streptococci and staphylococci.These are found 
in cases of septicemia, pyeemia, ulcerative endocarditis, 
&c.; they always indicate an extremely bad prognosis. 
The chief importance which attaches to the discovery 
of these organisms is that it absolutely settles the 
diagnosis (always provided that there are no errors in 
technique) and that it indicates whether the use of anti- 
streptococcic serum is advisable or not; it is useless in 
cases of septicemia, &c., which are not due to strepto- 
cocci. 
A word of warning is necessary in the interpretation 
of results which indicate that staphylocci are present in 
the biood. These organisms are constantly present in 
the skin and may be found in film preparations or in 
