L. J. Curtman and P. Gross 



171 



TABLE 5 



Data pertaining to the determination of aluminum by the Schmidt-Hoagland 



method 



In Table 6 are given the results obtained, with this method, 

 with dog and ox bloods^*^ to which definite quantities of aluminum 

 had been added. 



TABLE 6 



Data pertaining to the determination of aluminum in hlood by the Schmidt- 

 Hoagland method 



It was not thought necessary to investigate the method of the 

 Dep't of Agric, for the reason that, even if it did yield as accurate 

 results as those obtained above by the method of Schmidt and Hoag- 

 land, the longer time and the number of different Operations re- 

 quired, as compared with the method of Schmidt and Hoagland, 

 would cause its rejection. In the method of Schmidt and Hoagland 

 a direct gravimetric estimation of aluminum is made by a procedure 

 involving two precipitations and one ignition. The official method, 

 on the other hand, requires a precipitation of the iron and aluminum 

 as phosphate, fusion of the precipitate, and an estimation of the 

 contained P2O5 ; finally a Volumetrie determination of the iron in a 

 separate portion calling for a Standard sol. of KMn04. This pro- 

 cedure necessitates at least three precipitations, two ignitions and 

 weighings, and one titration. It is evident, therefore, that all the 

 objections to Steel's method on the score of technique apply here 



10 The blood was oxidized by the method of Steel : Loc. cit. 



