32 Notes from the Physiological Laboratory 



Four or five drops of Millon's reagent are now 

 added, the contents of the vessel thoroughly stirred 

 or shaken. Under these circumstances the presence 

 of peptone in amounts of less than one part in five 

 thousand is readily shown. By reducing the quan- 

 tities of the reagents used it is possible to demon- 

 strate the presence of peptone in a solution con- 

 taining but one part of that body in seventeen 

 thousand parts of water. 



The conditions interfering with this reaction are : 

 alkalinity of the fluid examined (readily overcome 

 by neutralization) ; heat, which has the same influ- 

 ence upon the nascent mercuric iodide as have pep- 

 tone and the bile-salts; and the presence of certain 

 compounds, as potassium ferrocyanide, which chem- 

 ically prevent the production of the mercuric 

 iodide. 



The following bodies in moderate amount do not 

 affect the reaction : saliva, syntonin, amygdalin, 

 para-albumen, diastase, kreatin, leucin, tyrosin, 

 mucic acid, glucose, urea, uric acid, nitric, hydro- 

 chloric, sulphuric, and picric acids, glycerine, alco- 

 hol, atropia sulphate, pilocarpin nitrate, caffeine, 

 sodium carbonate, ammonium oxalate, sodium 

 phosphate, and manganese chloride and ferric 

 chloride. 



