KOUTINE EXAMINATION OF MATERIAL 137 



very convenient for transport is to make two constrictions on 

 the glass tube at suitable distances, according to the amount of 

 fluid to be taken. The fluid is drawn up into the part between 

 the constrictions, but so as not to fill it completely. The tube 

 is then broken through at both constrictions, and the thin ends 

 an- sealed by heating in a flame. 



Solid organs to be examined should, if possible, be obtained 

 whole. They may be treated in one of two ways. (1) The 

 surface over one part about an inch broad is seared with a 

 cautery heated to dull red heat. All superficial organisms are 

 thus killed. An incision is made in this seared zone with a 

 sterile scalpel, and small quantities of the juice are removed by 

 a platinum spud to make cover-glass preparations and plate 

 or smear cultures. (2) An alternative method is as follows : 

 The surface is sterilised by soaking it well with 1 to 1000 

 corrosive sublimate for half an hour. It is then dried, and the 

 capsule of the organ is cut through with a sterile knife, the 

 incision being further deepened by tearing. In this way a 

 perfectly uncontaminated surface is obtained. Hints are often 

 obtained from the clinical history of the case as to what the 

 procedure ought to be in examination. Thus, as a matter of 

 practice, cultures of tubercle and often of glanders bacilli can 

 be easily obtained only by inoculation experiments. Typhoid 

 bacilli need hardly be looked for in the faeces after the first ten 

 days of the disease, and so on. 



Eoutine Procedure in Bacteriological Examination of 

 Material. In the case of a discharge regarding which nothing 

 is known, the following procedure should be adopted : 

 (1) Several cover-glass preparations should be made. One ought 

 to be stained with saturated watery methylene-blue, one with 

 a stain containing a mordant such as Ziehl-Neelsen carbol- 

 fuchsin, one by Gram's method. (2) a. Gelatin plates should 

 be made and kept at room temperature ; b. a series of agar 

 plates or successive strokes on agar tubes (p. 60) should be made 

 and incubated at 37 C. Method b of course gives results 

 more quickly. In every case when an unknown disease is 

 being investigated, some of the material should be subjected to 

 methods suitable to the growth of anaerobic bacteria. If micro- 

 scopic investigation reveals the presence of bacteria, it is well 

 to keep the material in a cool place till next day, when, if no 

 growth has appeared in the incubated agar, some other culture 

 medium (e.y. blood serum or agar smeared with blood) may be 

 employed. If growth has taken place, say in the agar plates, 

 one with about two hundred or fewer colonies should be made 



