64 R. R. BENSLEY. 



as with sections treated with a pure solution of molybdic acid. 

 These facts dispose finally of the first and second essential con- 

 ditions of a successful microchemical reaction for organic phos- 

 phorus, for it is clear that if the sections after treatment with 

 the reagent contain no phosphomolybdate of ammonium, that 

 the organic phosphorus has either not been liberated from its 

 compounds, or that, if it has, it has not been precipitated at 

 the moment and at the point of liberation. If these conclu- 

 sions are correct, it is also obvious that there is no hope of a 

 real phosphorus microchemical reaction being obtained by the 

 employment of the nitric molybdate reagent. 



These conclusions do not, of course, apply to the identifica- 

 tion of phosphates by the nitric molybdate reagent, in cases 

 where the characteristic crystal form of the ammonium phospho- 

 molybdate can be recognized under the microscope. 



In conclusion, it may be mentioned that in making the experi- 

 ments to determine the effect of nitric acid on the reduction of 

 the molybdenum compounds by phenylhydrazin hydrochloride 

 it is important to employ solutions which are free from nitrous 

 acid, which reacts with the phenylhydrazin and reduces its con- 

 centration. 



BIBLIOGRAPHY. 



Bensley, R. R. 



'03 The Structure of the Glands of Brunner. The Decennial Publications, Uni- 

 versity of Chicago, Vol. X., 1903, pp. 279-326. 



Gourlay, F. 



'94 Proteids of the 1'hyroid and Spleen. J. Physiol., Cambridge, Vol. 16,1894, 



PP- 23-33- 

 Graham, T. 



'64 On the Properties of Silicic Acid and other Analogous Colloidal Substances. 

 J. Chem. Soc., Lond., n. s., Vol. 2, 1864, pp. 318-327. 



Heine, L. 



'96 Ueber die Molybdansaure als mikroskopisches Reagenz. Ztschr. f. physiol. 

 Chem., Strassburg, Bd. 22, 1896-97, pp. 132-136. 



Held, H. 



'95 Beitrage zur Structur der Nervenzellen undihrer Fortsatze. Arch. f. Anal. u. 

 Entwicklngsgesch., Leipzig, 1895, pp. 396-414. 



