THE ANAEROBIC BACILLI 765 



by means of smears in such a way that an approximate estimate 

 of the number of bacteria contained in the wounds can be made. 

 Although the method is very inaccurate, its value does not depend 

 upon its revealing slight differences, the significant variations being 

 so widely apart that the necessary error in the comparative enumera- 

 tions does not render the method useless. 



The examination need not begin earlier than twelve hours after 

 the infliction of the wound, since up to that time few bacteria will 

 be found. At the end of this time, when hemorrhage has completely 

 stopped, smears are taken with a platinum loop from different parts 

 of the wound. The points from which cultures are taken should 

 always be those in which bacteria are most likely to be present 

 in large numbers. Thus, Carrel chooses points in contact with 

 foreign bodies, necrotic bits of bone, and from deep in the sinuses 

 and crevices of the wound. Specimens should never be taken from 

 bleeding points. Specimens should always be taken from a consider- 

 able number of different places in the same wound. Care should be 

 exercised to avoid taking smears from the skin adjacent to the 

 wound. With the end of a small platinum loop small amounts of 

 secretion are picked up, and smeared upon slides in such a way 

 that approximately the same area is covered by the different 

 loopfuls of secretion. With loops of uniform size and a little prac- 

 tice, a surprising uniformity of technique can be developed. 



These smears are allowed to dry, and may be stained in a 

 variety of ways. Carbol thionin has been extensively used, but we 

 believe that a Gram stain which is almost as simple, will give a 

 little more useful information. 



The stained slides can now be examined under the microscope 

 and the number of bacteria per field, counted. If the number exceeds 

 fifty or more to the field, more accurate counting will yield no 

 valuable information because the wound still contains too many 

 bacteria to warrant closure or relaxation of the local therapy that 

 is being applied. 



Gradually, as the wound improves, less and less bacteria will 

 appear in the daily series of slides, and when it has dropped below 

 fifty per field, careful counting may give an index of daily variations. 

 Eventually, they will drop to only one microorganism per five, ten 

 or twenty fields, in which case the daily report can be expressed in 

 fractions, as 1/5, 1/10, or 1/20, etc. The daily counts can, in this 

 way, be numerically charted, and constructed into a curve which 



