TYPHOID 179 



diagnosis of typhoid fever was at once taken up by several 

 investigators. 



To carry out the test two things are required — the blood 

 serum to be tested in a diluted condition, and a broth 

 culture of typhoid bacilli, not more than twenty-four hours 

 old, containing the organisms in an actively motile condi- 

 tion. In place of the last a little of the growth on an 

 agar culture of the same age may be taken, and rubbed up 

 with a little broth in a watch-glass so as to produce a 

 uniform emulsion. Several observers have published some 

 modification of the test, but the following method as 

 described by Griinbaum* is probably the best : The lobe of 

 one of the patient's ears is washed with ether or some other 

 suitable antiseptic. The ear is preferable to the finger 

 because it is more easily cleaned and the epidermis is 

 thinner (especially among the working classes) ; it is also 

 more vascular, yet less sensitive. With a straight spear- 

 pointed surgical needle, or with one half of a fine steel nib, 

 a prick is made into the lobe and the blood collected in a 

 capillary tube. By suitable pressure and a little patience 

 an almost indefinite quantity can be collected from this 

 source. The capillary tube should not be too narrow ; an 

 ordinary vaccine tube is a little too wide, but can be used 

 without much disadvantage if no other is available. On 

 the whole, capillary tubes bent into V-shape are the most 

 convenient. Care should be taken that the blood forms a 

 continuous column in the tube ; if it has flowed a little way 

 down the tube in the interval required to press out a fresh 

 drop of blood from the ear, it should be made to flow back 

 to the end before collecting again, so that there may be no 

 air space in the tube. The blood having been collected, 

 the ends of the tube should be cautiously sealed in the 

 flame, care being taken that the blood is so far away from 



* ' Treatment,' vol. i., p. 73. 



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