33() DIFFERENTIATION AND SPECIFICITY OP STARCHES, 



The Mean Temperatures of Gelatinization of Various Starches. — Continued. 



Maranta musaica 88.50° ' Actaea spicata var. rubra 56.50° 



Calathea liotzci 78.50° Cimicifuga racemosa 59.50° 



Calathea vittata 83.25° Eranthis hyeinalis 51.50° 



Calathea wiotiana 85.50° Ranunculus bulbosus 56.00° 



Calathea vandenheckei 77.75° Ranunculus ficaria 64.00° 



Stromanthe sanguinea 82.75° Adonis amurensis 64.50'' 



Nymphcea alba 69.00° Cochlearia armoracia 62.50° 



Nymphaea marliacea var. albida 68.00° ' Jatropha curcas 59.50° 



Nymphfca marliacea var. carnea 66.50° Manihot utilissima 62.00° 



Nympha;a gladstoniana 70.00° ' Cyclamen repandum 55.50° 



Nymphaea odorata 67.60° Cyclamen coum 56.50° 



Nymphffia odorata var. rosea 67.00° Solanum tuberosum 66.00° 



Nelumbo nucifera 58.75° Batatas edulia 74.00° 



Nelumbo lutea 60.00° Gesneria tubifiora 64.50° 



Anemone apennina 53.60° Gloxinia var 69.25° 



Anemone fulgens 60.75* Trianosperma ficifolia 59.00° 



Anemone blanda 53.25° Cycas revoluta 73.50° 



Anemone japonica 63.00° Cycas circinalis 72.00° 



Aconitum napellus 52.75° Dioon edule 72.50° 



Actfea alba 56.00° Zamia integrifolia 76.50° 



Especial attention may be directed to the figures of the foregoing table for compari- 

 son with those recorded by other investigators, and also to certain features regarding the 

 range of temperature of gelatinization of the starches as a whole. The records of Lipp- 

 mann (page 175), from the time of their publication, over 50 years ago, have hatl a very 

 wide publication and generally have been accepted as standards of reference, but the 

 methods used by him and succeeding workers are crude and liable to lead to very fallacious 

 results. Since Lippmann's studies, Uttle has been published on the temperatures of gelat- 

 inization, notwithstanding that much literature has acciunulated that treats of the properties 

 of starch, and the inherent importance of the meanings of differences of such temperatures 

 in relation to the starches of different plant sources. This seeming neglect is doubtless 

 to be accounted for in the very variable results that must have been obtained by various 

 experimenters who have felt that their records were unworthy of publication. Wliymper 

 (page 175), for instance, found with barley, maize, rye, potato, rice, wheat, and tapioca 

 starches that the values differed in most cases from previous figures and varied with the 

 maturity and size of the grains. Such discrepancies are illustrated in the case of rice 

 starch, the temperatures by Lippmann, Lintner, and Dafert being G1.25°, 80°, and 73°, 

 respectively; of barley, Lippmann recording 62.5°, and Lintner 80°; of corn starch, Lippmann 

 givmg 62.5° and Lintner 75°; and of ivheat starch, Li])pmann recording 67.5° and Lintner 

 75° to 80°. Li the preceding table the temperatures given as determined by the method 

 used in this research are for the same starches, rice 74.75°, barley 61°, cor7i 63.25° to 68.5°, 

 and wheat 62.9° to 64° — the last two varying according to the variety. 



The lowest temperatures recorded were among the Liliaceo} (among members of 

 Tulipece — Calochortus, Tulipa, and Erythronium) in which in six instances the figures 

 ranged between 49.60° and 50.95°; while the other extreme, where the temperature exceeded 

 85°, was noted among the Zingiberaccce {Zingiber) and Marantaceoe {Maranta and Calathea), 

 the highest being 90° — a range of over 40°, which is certainly remarkable. Of the total 

 number of starches studied, 0.3 per cent had a temperature of gelatinization in the forties, 

 20 per cent in the fifties, 39 per cent in the sixties, 34 per cent in the seventies, and some- 

 what more than 6 per cent from eighty to ninety. Nearly 75 per cent had a temperature 

 of gelatinization between 60° and 80°, and about 65 per cent between 60° and 75°. 



