BACTERIOLOGICAL TECHNIC 



8l 



the suspected throat area, and then lightly rubs it over the surface of the 

 serum tube slant. The swab is returned to the tube, the cotton plug is re- 

 stored and then returned to the board of health to be destroyed in stove 

 or furnace fire, or destroyed by the attending physician in case there is no 

 board of health to receive it. 



7. Making Bacterial Cultures 



This branch of the science of bacteriology is of comparatively little 

 importance to the pharmacist. While it is desirable to know what bacterial 

 cultures are and how to make some of them, it is wholly unlikely that the 

 pharmacist will be called upon to do extensive work along this line. This 

 is the work of those who make bacteriology a specialty. 

 Such bacterial cultures as are likely to come to the notice 

 of pharmacists will most generally be prepared by phy- 

 sicians, health officers, and other specialists in bacteriology. 

 The pharmaceutical bacteriologist may be called upon to 

 make bacterial examinations of drinking water, of milk, 

 of ice cream, and other food materials; of syrups, liquors, 

 aquae, tinctures, fluidextracts, infusions, etc., and he 

 should, if possessed of some skill and adequate labora- 

 tory facilities, be able to do so. 



The prime object in' growing bacteria in artificial 

 culture media is to make possible their further more care- 

 ful and more extended study. The study of bacteria in 

 their natural or normal surroundings is all-important, 

 but is not complete without the artificial culturing. 



As a rule, bacteria are biologically associated with 

 other organisms, and it is unusual to find pure cultures 

 in nature or in natural media. An open sore may contain 

 several or many species and varieties of bacteria, in addi- 

 tion to the pus germs. The intestinal tract of the cholera 

 patient contains bacteria other than the comma bacillus 

 of Koch. The tubercular bronchials always show a 

 mixed infection. The diphtheric membrane contains 

 some foreign germs, etc. Some infections, particularly 

 those of internal tissues or organs, as lymphatic glands 

 for example, may present practically pure cultures. 

 However, no matter how mixed an infection may be, 

 there is always a predominating type present, or, to state it more cor- 

 rectly, it is the greater development of the predominating type which 

 determines the diagnostic characteristics of the infection. 



It must also be borne in mind that bacteria behave differently when 



6 



FIG. 30. Cotton- 

 plugged tube 

 with a potato 

 slant resting on a 

 bit of glass rod to 

 keep the potato 

 out of the water 

 in the bottom of 

 the tube. (Will- 

 iams.) 



