be noticed by the consumer. But while this is true of most of the pre- 

 servatives used in the preparation of foods (except the condimental 

 substances mentioned) in the quantities employed, this does not mean 

 that in a concentrated form they have neither taste nor odor. Quite 

 the contrary is true. Nearly all of them in a concentrated state reveal 

 themselves either by taste or by odor. For instance, salicylic acid in a 

 pure state is easily distinguished by the taste, and' sulphurous acid in 

 the form of gas or in a nearly saturated solution is distinguished by its 

 odor and irritant effect upon the nostrils. Nevertheless small quantities 

 of salicylic acid can be placed in food products without the consumer 

 being able to detect it, and the same is true of sulphurous acid. 



Legislation of various kinds in different countries and in the different 

 States of the United States 1 has been enacted concerning the use of 

 preservatives and coloring matters in foods. This legislation is of 

 varying character, prohibiting in some countries what is allowed in 

 others, establishing rules and regulations which are local in character,] 

 and, in general, producing a state of affairs which is annoying to the 

 manufacturer of food products and the dealers therein, and which, by 

 the diversity of laws and decisions relating thereto, does not secure to 

 the consumer the full benefit which was intended. The desirability of 

 some investigation, therefore, was apparent, in order to establish certain 

 principles concerning the use or prohibition of these substances, which t 

 by reason of their more general applicability, may influence local and 

 general legislation in a matter tending to secure a greater uniformity 

 and efficiency, it is also evident that if these investigations could be 

 conducted under some direction not particularly interested in the con-.- 

 struction of any law, nor associated in any commercial way with the 

 interests of either manufacturer or consumer, they would have a 

 greater weight. 



The Secretary of Agriculture is manifestly the proper official to 

 undertake and direct such an investigation. The interests of the 

 Department over which he presides are associated alike with producers,, 

 manufacturers, and consumers of food products, and thus any bias 

 which might exist in other quarters in favor of any particular interest 

 would be eliminated. For this reason the investigations conducted 

 tinder his direction, even if no more thorough, painstaking, or reliable 

 than if carried on under other auspices, would be commended more 

 generally by reason of their freedom from influences which might tend 

 to divert them from their intended purposes. 



PLAN OF THE INVESTIGATION. 



In determining the method by which these investigations should ba: 

 conducted a careful study was made of similar researches carried on 



^U. S. Dept. of Agr., Bureau of Chemistry, Bui. 69, Parts I- VI ; Bui. 83^ 

 Part I. 



