Precipitin Test for Tuberculosis 351 



found to have evidence of tuberculosis. One died from hyper- 

 tension, and at autopsy an active lesion was found in the apex 

 of the right lung. 



An interesting case was that of a newborn, whose mother was 

 a far advanced case, giving a negative Von Pirquet but a posi- 

 tive precipitin test. The blood of the newborn gave a heavy 

 precipitin reaction. 



Of the 90 sanatorium cases 85 were positive and 5 negative. 

 The 5 negative cases were either "healed" or "arrested." 



We have found that the acid fast actinomycetes, as A. gyp- 

 soidcs and A. astcroides, make a good antigens as the tubercle 

 bacillus. On the other hand the non-acid fast actinomycetes 

 fail to react with tubercular serums. This is in agreement with 

 the findings of Henrici and Gardner 2 and Nelson and Renrici. 3 



The glycerine broth filtrate of the tubercle bacilli as of the 

 actinomycetes fails to give this reaction. 



171 (2131) 



The determination of iodin in iodin metabolism. 

 By J. F. McCLENDON. 



[From the Laboratory of Physiologic Chemistry, University of 

 Minnesota, Minneapolis, Minnesota.] 



The organic material for iodin analysis is dried, mixed with 

 and covered with CaO to render it alkaline and reduce the rate 

 of combustion, and burned in pure oxygen in a large combustion 

 tube with the end narrowed and bent downward for about 50 cm. 

 The first third of this narrowed portion is covered with a thin 

 layer of asbestos fibers to protect it from a lead coil through 

 which cold water runs. The middle third is water-jacketed. The 

 lower third dips into an absorbing apparatus filled with NaOH 

 solution. The greater the amount of CaO mixed with the un- 



2 Jour. Inf. Dis., 1921, xxviii, 237-248. 



3 Proc. Soc. Exp. Biol, and Med., 1921, xix, 351-352. 



