CHAPTER VIIL 



GENERAL APPLICATIONS OF THE RESULTS OF THIS RESEARCH. 



SPECIFICITY AND CONSTANCY OF THE STEREOCHEMIC CHARACTERS OF STARCHES IN 



RELATION TO GENERA AND SPECIES. 



Reference has so frequently been made to the relations of the reactions in both sjieci- 

 ficity and constancy to genera and species that it would be almost a matter of superero- 

 p;ation to do more at this point than to lay down the dictum that as starch-producing 

 plants become modified in their botanical characters the properties of the complex syn- 

 thetized substances, such as starch, are accordingly modified, and hence that every genus 

 and species has a form of starch which is specific and constant in relation to that genus 

 or species. Evidence in support of tliis is found throughout the work. 



In the investigations on the crystallography of hemoglobins, referred to in the Preface, 

 it was found that these substances exhibit differences which are in specific relationship 

 to genera and species; and, moreover, that the results of a few preliminary studies with 

 plant proteins and certain other groups of corresponding vital substances justified the 

 announcement of the belief that the remarkable zoological distinctions shown by the 

 hemoglobins would be found to be presented by other complex organic metabolites. 

 Furthermore, it was made clear that not only does there exist these specific stereochemic 

 differences, but also that there are definite gradations of these differences which correspond 

 with the positions occupied by animals in relation to one another as is recognized by the 

 systematic zoologist. Upon such a basis, one may assume upon logical grounds that 

 corresponding gradations will be demonstrated to exist between starches and plants. It 

 follows, as a corollary, that in the existence of individualities of corresponding stereoisomers 

 in relation to genus and species we have a strictly scientific basis for the classification of 

 plants and animals. 



APPLICATIONS OF THE RESULTS OF THIS RESEARCH TO PHARMACOGNOSTICS, COMMERCE, 



AND TECHNICAL PURSUITS. 



The grains of the starches of vegetable drugs vary considerably in size, shape, and 

 other characteristics, as is instanced in the classification of starches by lu'aemer (page 71). 

 It is well known that differences merely in the histological characters of starches are often 

 of value in suggesting or practically determining the plant source, but it is also clear, as 

 has been frequently pointed out, that the histological method may be absolutely misleading. 

 If, therefore, there be coupled with this method such others as have been employed in this 

 research, especially in the examination of storage starches (as those of seeds, tubers, 

 rhizomes, conns, etc.), the identification and the determination of substitution and adul- 

 teration of drugs that contain starch are usually rendered quite easy. 



Commercial starches probably number about thirty, including among them particularly 

 those of corn, rice, and white potato, together with the relatively many lands that are 

 marketed solely or chiefly as "arrowroot." The first three starches are, as is well known, 

 used extensively in various technical industries and in the arts, and as articles of food, 

 while the arro\vroots are sold almost entirely as articles of diet, especially for the use of 

 the sick. The recognition of corn, rice, and white potato starches, respectively, and the 

 detection of adulterations, substitutions, and gross impurities is a matter of common 



22 337 



