194 Sanitary Studies of Baking P^owders 



aluminium in biological materials, as these methods are currently con- 

 ducted. The disparity between the results reported by Steel, and by 

 Curtman and Gross, for Steel's method, may be due (as Steel sug- 

 gests) to differences in the degrees of heat applied during the 

 ignition of the precipitates.^ 



As soon as the general outcome of the studies published in the 

 four preceding papers (2-5) was apparent, the work on the second 

 and third phases of the research — on the absorption of aluminium 

 from aluminized bread, in men and dogs — was begun, and the 

 Schmidt-Hoagland method adopted thruout as the best of the avail- 

 able ones for the determination of aluminium in biological materials. 

 The reports on these parts of the investigation were completed, and 

 in my possession, before the corrected proofs of the four preceding 

 papers (2-5) went to the authors. 



The succeeding paper, by Balls, throws further light on the ques- 

 tion of the accuracy of our "best" method. Balls' findings ^eem to 

 indicate that the Schmidt-Hoagland method may fail to recover the 

 füll amount of aluminium involved. There is special need for a 

 new method that would overcome all the objections against the best 

 of the processes that are now available for the estimation of alu- 

 minium in biological materials. 



The remaining papers in this series — on the absorption of alu- 

 minium — will be published in the next issue of the Biochemical 

 Bulletin. 



ß See the succeeding paper, by Balls, for further intimations regarding the 

 discordant influences of diflferent temperatures and periods of ignition. 



