ui:a«"I h>\-ivii:\srni> wiiii EACH AGENT AND REAGENT. 



]:>:>, 



very much higher sensitivity than the former; while 

 with potassium hydroxide there are three gradatio 

 sensitivity. The reactions of Iris persica var. pur\ 

 differentiate it from the firs! three members of this 

 genus. Another feature is seen in the very sti 

 differences in Begonia; in the first Begonia both reai 

 tions are very high and the same, while in the second the 

 potassium-hydroxide reaction is similarly high and the 

 sodium-hydroxide reaction is low and far separated from 

 the former. 



Potassium sulphide and so, limn sulphide (Chart 

 B 3-1) elicil reactions which as a whole are quite different 

 from those recorded in the preceding charts, but arc 

 nevertheless in entire support of the fundamental pecu- 

 liarities that have been found to be set forth by the 

 reactions of each pair of reagents thus far studied— that 

 is, an independence of each reagent in its reactions thai 

 is due to both concentration and kind of solute; an inde- 

 pendence of the reactions of each starch that is dependent 

 upon differences in stereoisomeric forms; and an inde- 

 pendence of the course of each curve to such a degree 

 that there may not only be most variable quantitative 

 differences but also inversion, yet with a manifest ten- 

 dency to conforming with the peculiarities of a prototype 

 (say the nitric-acid curve). Probably the first feature 

 that will attract attention is the very marked differences 

 in the behaviors of Amaryllis and Brunsvigia with these 

 closely related reagents, the former exhibiting a very 

 high reactivity with potassium sulphide and a moderate 

 reactivity with sodium sulphide, thus showing a very 

 wide difference in reactivity, there being 97 per cent of 

 the total starch of Amaryllis gelatinized in 3 minutes 

 and only 91 per cent of the total starch of Brunsvigia 

 in 60 minutes; whereas with sodium sulphide the reac- 

 tivities of both starches are very nearly the same, 90 and 

 96 per cent, respectively, in 60 minutes being recorded. 

 Amaryllis throughout the course of the reaction showing 

 only slightly less reactivity than Brunsvigia. 



It will be noted that the two curves here are entirely 

 differeni from those of the three preceding charts (Charts 

 B31, B3?, and B33), which also so differ from each 

 other that each chart is very definitely individualized. 

 The reactions of the sulphides arc the same or practically 

 the same in Brunsvigia josephince, Hippeastrum titan, 

 II . ossultan, Hcemanthus josephince, Crinum zeylanicum, 

 Lilium martagon, L. tenuifolium, L. chalcedonicum, /,. 

 pardaiinum, and Begonia single crimson scarlet. The 

 potassium-sulphide reactions arc higher in Amaryllis bel- 

 ladonna, Hainan/has puniceus, Nerine crispa, N. bow- 

 deni, A . sarniensis var. corusca major, Begonia socotrana, 

 and Pliaius grandifoliusj and lower in Hippeastrum 

 dceones, Crinum moorei, C. longifolium, Narcissus tazetta 

 grand monarque, Iris iberica, I. trojana, /. cengialti, I. 

 persica var. purpurea. Gladiolus tristis, Tritonia pottsii, 

 and Miltonia vexillaria. For the most pari the curves are 

 well separated, this feature being particularly accen- 

 tuated in Amaryllis belladonna, Crinum moorei, Nerine 

 crispa, Iris persica var. purpurea, and /•'< gonia socotrana. 

 Hcemanthus katherina and //. puniceus are not nearl} 

 so well differentiated as in the preceding charts; the 

 hardy and tender Crinums arc well differentiated, as 

 in the previous pairs of reactions. The Trids show n 

 the same reactivities with potassium sulphide, while three 



-how n, ;nl;, the same rea 



hut higher than with potas ium ulphide, and o 



much higher n than the idium 



sulphide and a on to 



ul|, hide, show in;' a marl I 



division such as was noted with other in 



■ ///.sand Tritonia the potassium-sulph 

 well below the ulphide curves, thi 



each hem-' al I tin' ame. 1 1, I I he differentia- 



tion of the two starches is very striking. In /' 

 MUlonia the generic differences are pronounced, 

 onl\ in regard to the ,|, , paration of the cui 



hut also in respeel to the inversion of the curves. The 

 high reactivities shown in Amaryllis ! 

 crispa, and Begonia soci ium sulphide 



in comparison with the moderate to yery low n 

 with the other reagent, together with the very opp 

 in Crinum moorei, Iris persica var. purpurea, and Mil- 

 tonia bleuana, are striking manifestations of diffen 

 iu the molecular constitution of starches from diff 

 plant sources. 



The reaction-inten ities of potassium iodide and po- 

 tassium sulphocyanate (chart B 35) p ery much 

 closer relationships than do those of any of the pairs of 

 reagents thus far considered, yet here also are i 

 the fundamental peculiarity - thai havi cl ara b rized all 

 of the comparisons brought out in the preceding charts. 

 The reactivities of these reagents are the same a Ha 

 thus katherince, Crinum moorei, C. zeylanicum, c. 

 folium, Lilium martagon, L. tenuifolium, L. chalcedoni- 

 cum, L. pardaiinum, and Begonia single crimson scarlet. 

 The reactions of potassium iodide are higher than those 

 of potassium sulphocyanate in Amaryllis belladonna and 

 Brunsvigia josepliince, and lower with all of the remain- 

 ing starches, except the group noted. The curves show 

 for the mo.-t part a marked concordance in their up- 

 and-down movements, hut the degree of separation of 

 the curves is quite variable and there are inversions only 

 of A maryllis and Brunsvigia. 



A comparative examination of the curves ( >f the reac- 

 tions of sodium hydroxide and Bodium salicylate (Chart 

 11 oil) brings out one wry i nal feature that is 



associated with the latter reagent, an, I various feal 

 that are in harmony with characteristics thai are com- 

 mon to the other charts. The marked limitations of the 

 reactions of sodium salicylate are most striking and 

 peculiar to this reagent. In only two reactions (those 

 with Crinum zeylanicum and Begonia single crin 

 scarlet) is there a departure from the narrow limits of 

 the upper six abscissae (a trifle more than one-fourth 

 of the highest and lowest limit- of reaction-inl 

 This limitation greatly restricts the value 

 in the differentiation of starches from different plant 

 source-, yet there are in some instance- n i very 



marked differentiation, especially of subgeneric groups. 

 The differences in the reactions of the two spe< 

 Hcemanthus are not of themselves sufficient to definitely 

 indicate subgeneric division, but rather well- 

 species; in Crinum the two hardy forms are v, 

 entiated from the tender form; in Iris the tirst three 

 stand definitely apart from the fourth: and ii B 

 there are striking differences betwei o the two si a 



