1914] Frank L. Haley 441 



in which a flaming electric arc is discharging. More recently the 

 use of nitrosyl chlorid has been introduced as a means of bleaching 

 flour, and possesses advantages over the oxid of nitrogen in the char- 

 acter of the bleach which it produces as well as in the simplicity of 

 application to the flour. 



Is there any difference chemically between bleached and un- 

 bleached flour? Analyses have shown that the chemical composi- 

 tion of both is practically the same, with the exception that in the 

 case of bleached flour nitrite is present, whereas in the unbleached 

 flour, nitrite is absent. Analyses made by me have corroborated 

 this fact, as shown in detail by the f ollowing summaries : 



Average analytic data : 

 Unbleached flour. Bleached flour. 



Per Cent. Pei Cent. 



Nitrogen 2.47 Nitrogen 2.43 



Proteins 15.73 Proteins 15.48 



Fat 1.73 Fat 1.92 



Dry gluten 11.60 Dry gluten 11.37 



Moist gluten 29.29 Moist gluten 31.02 



Phosphate (P.O5) 0.508 Phosphate (P^O,) 0.598 



Nitrite absent Nitrite present. 



The presence of nitrite in flour has led to a great deal of dis- 

 cussion as to whether or not the use of bleached flour is injurious 

 to health. Some investigators claim that the presence of nitrite in 

 flour reduces the oxyhemoglobin of the blood to methemoglobin. 

 In Order to prove or disprove this claim we have conducted a num- 

 ber of experiments upon guinea pigs and rabbits in the f ollowing 

 manner. Each of six healthy guinea pigs was given, morning and 

 night by mouth, one drop of i percent sol. of potassium nitrite, 

 i. e., about i mg. of KNO2. At the end of three weeks, several 

 drops of blood were obtained from an ear of each guinea pig, mixed 

 with IG cc. of physiological salt Solution, and examinations made 

 with the spectroscope. In every case the blood showed only normal 

 oxyhemoglobin. Spectroscope readings were made at intervals of 

 three days, with negative results. 



A modification of the first experiment was begun, six weeks 

 after the first experiment was started, with anothersetof guinea pigs. 



