236 ^AUiminmm from Aluminised Foods [Dec. 



investigated." The practical importance of such a study is so evi- 

 dent that comment is superfluous. At Prof. Gies' Suggestion the 

 experiments described below were conducted for the purpose of 

 extending our knowledge in this particular direction. 



II. DESCRIPTION OF THE EXPERIMENTS 



Preliminary supplies and conditions. The experiments were 

 conducted on normal, healthy dogs, kept in cages which have long 

 been in constant use in this laboratory.^ The animals were fed 

 daily at 9 A. M. The diet consisted, with the exceptions herein- 

 after noted, of 10 grams of hashed lean beef (taken from large sup- 

 plies preserved in a frozen condition),^ 15 grams of biscuit baked 

 by the process detailed below, 3 grams of lard, i gram of bone ash 

 and 35 CG. of water — per kilo of weight of the dog. The baking of 

 the biscuits was done according to the directions of Professor 

 Mallet.* The flour selected was of the best quality for family use. 

 Three large bags of Hecker's flour were bought. Each bag was 

 emptied into a large porcelain dish and the flour thoroughly mixed. 

 The flour from each bag was kept in large, wide mouthed, glass 

 stoppered bottles. A sample of flour from each bag was analyzed 

 for aluminium, but not a trace of aluminium could be found in 

 the portions examined. In Prof. Mallet's experiments, "the flour 

 used yielded in the ash the equivalent of less than i mg. of AI2O3 

 for the largest quantity of bread eaten by any of the subjects."^ 



" Bob White " baking powder was used. This is a " straight 

 alum " powder. It was purchased in the open market. The label on 

 each package gave the following summary of the contents : Com 

 starch, sodium aluminium sulfate (32.75 per cent.), sodium bicar- 

 bonate. 



The ingredients for the baking were mixed in the following pro- 

 portions: Flour, 550 grams; common salt, 8 grams; sucrose, 5 

 grams; "Bob White" baking powder, 16 grams; water, enough to 

 make a biscuit dough. Before the water was added, the flour, 

 baking powder, etc., were thoroughly mixed, to insure uniform 



" Gies : American Journal of Physiology, 1905, xv, p. 403. 



* Gies : Ibid., 1901, v, p. 235. 



*Gies: Journal of the American Medical Association, 191 1, Ivü, p. 817. 



'Gies: Ibid. (footnote). 



