152 Sanitary Studies of Baking Powders 



The gist of our conclusions, from the results of these experi- 

 ments, is indicated by the f ollowing four quotations : 



I. " Compounds of aluminium, such as the chlorid, even when 

 present in very minute proportions, are streng protoplasmic poisons and 

 very toxic to growing plants " (House). 



II. " When alum was administered in aluminium-f ree food to dogs, 

 or when dogs ingested biscuits baked with alum baking powder, alu- 

 minium in comparatively large amounts promptly passed into the blood. 

 . . . When aluminium chlorid was administered intravenously, from 

 5.55 percent to 11. 11 percent of the aluminium passed from the blood 

 into the feces during the three days immediately after the injection" 

 (Steel). 



III. " When biscuits baked with alum baking powder are fed in a 

 mixed diet to dogs, aluminium passes in considerable amounts into the 

 blood. Such absorbed aluminium circulates freely and, although it 

 does not show a tendency to increase proportionately in the blood, it 

 accumulates to some extent in various parts of the body. The bile 

 contains a particularly large amount of aluminium. . . . Under the con- 

 ditions of these (feeding) experiments, aluminium is absorbed in part 

 and is excreted, to some extent, in both the bile and urine" (Kahn). 



IV. "Two objections might be raised against this conclusion re- 

 garding the absorption of aluminium from the gastro-intestinal tract 

 into the blood. It might be assumed that our analytic method was 

 inaccurate. Such an assumption is always in order in the considera- 

 tion of any method, for none is perfect. Our preliminary work with 

 the analytic method employed and the checks against error that were 

 instituted, give us complete confidence, however, in the practical ac- 

 curacy of the process. If slight and unavoidable errors occurred, we 

 believe that, from the general nature of the method, they must have 

 caused loss of aluminium and consequent diminution of the numerical 

 result, rather than the reverse.^ 



" It might also be urged that our figures representing the amounts 

 of aluminium which passed into the blood are too small to mean any- 

 thing. It might be thought that the proportions are too minute for the 

 causation of deleterious effects. It might even be suggested that such 

 small proportions of aluminium are beneficial because of the possible 

 ' stimulating ' action which traces of poisons f requently induce. But 



^ For fiirther facts in this connection see Gies : Biochemical Bulletin, 

 1916, V, p. 189. 



