SECTION-CUTTING 159 



plan is to sear the surface of the block, and then to tie a piece of 

 string round it and dip it quickly into melted paraffin (a candle 

 will do), and allow the coating to set ; the dipping is to be 

 repeated several times, and the specimen (string and all) may 

 then be packed without further precautions. In any case it must 

 reach the laboratory as soon as possible. 



Where cultural examinations are not required, small portions 

 of the organs should be placed in a suitable hardening fluid as 

 soon as possible. Equal parts of methylated spirit and water is 

 perhaps as good as anything, and, in the absence of this, undiluted 

 whisky or other spirit answers equally well (see p. 161). 



Other solid organs are treated in the same way. Fluids (pus, 

 the contents of cysts, pericardial or other fluid, etc.) should be 

 collected in pipettes in the manner adopted for the heart-blood. 



SECTION-CUTTING 



The methods employed in section-cutting are somewhat outside 

 the scope of this work, inasmuch as sections are rarely necessary 

 for the purposes of bacteriological diagnosis, and I have attempted 

 to give the simplest possible methods in all cases. The presence 

 of bacteria in the tissues can usually be demonstrated by the simple 

 processes of smearing the cut surfaces of tissues on clean slides 

 or cover-glasses, and treating the films thus obtained by the fixing 

 and staining methods previously described. If, for instance, we 

 have to search for tubercle bacilli in tuberculous glands, it is 

 usually sufficient to smear the cut surfaces of the glands on a slide, 

 dry, fix by heat, and stain in the same way as sputum is stained 

 for the tubercle bacillus. If anthrax bacilli were being looked for 

 in the liver or other organ removed post-mortem, the same 

 method of procedure would be adopted, except that Gram's 

 method of staining would be used. So also for typhoid bacilli in 

 the spleen, where the film would be stained with a simple stain 

 such as thionin or Loffler's methylene blue. 



It seems advisable, however, to give a short general account of 

 the processes involved in section-cutting, for they are by no means 

 difficult, and do not require very elaborate apparatus. Further, 

 the same methods of section-cutting are used for investigating 

 the nature of tumours, etc., and this is done already by many 

 practitioners and should be done by still more. 



