G94 



TUCKAHOE, OR INDIAN BREAD, 



])revioasly consulted were so different as to attacli nncertainty to all. 

 Several specimens for examination vrere placed in the hands of Professor 

 Colyer, chemist-in-chlef of the Agricultural Department, with the result 

 indicated by the following report, prepared by Dr. Henry B. Parsons, 

 assistant chemist, with the concurrence of Professor Colyer: 



"The first careful chemical examination of Tuckahoe was made by 

 Prof. Joh.n Torrey, in 1819 (Xew York Medical Repository, vol. 1, y>. 37). 

 He found the fungus to consist almost entirely of a hitherto undescribed 

 substance, not starch, which had the property of forming a jelly when 

 heated with water and allowed to cool. To this substance he assigned 

 the name 'sclerotin.' The later researches of Bracconnot on the jelly- 

 forming constituents of fruits and tubers were published in 1824, and 

 led to the adoption of the term 'pectous substances' (Ann. Chim. Phys. 

 vol. xxviii, p. 173). In 1827 Torrey republished his original article with 

 additions, and demonstrated that the substance he had named sclerotin 

 was identical with the pectic acid of Bracconnot (Med. & Phya. Jour., 

 vi, p. 484). In this conclusion he was certainly correct, as this gelatin- 

 ous substance deports itself exactly like pectic acid, as described in the 

 standard textbooks on proximate analysis (Prescott's Prox. Orig. Anal., 

 p. 1G6). In 1875 an analysis was made at the Bussey Institute. In this 

 the gelatinous substance is spoken of as pectose; in most respects the 

 analysis there made agrees very closely with the one here reported. 

 Trifling differences are to be ascribed to the examination of different 

 samples. 



Departinont 

 of ARricul- 

 turo. 



Bnssey In- 

 stitute. 



University 

 of Vir- 

 ginia. 



Moisture at 110° C . 

 Ash. 



AlbTiminoids : 



Soluble in alcohol, not in Tvator 



Soluble in water, not in alcohol .., 



Carboliydrates : 



Tarinin-lilie substance soluble in water 



Gam 



Pectic acid, by difference 



Fatty suhst.iuco soluble in gasoline 



Crude cellulose 



Mineral matter 



12.97 

 .24 



25) 



20 > 79. 88 



43 i 



.35 

 5.77 



14.57 

 .24 



L38 



73.73 



.34 

 9.80 



10.70 

 3.C4 



.76 



75.25 



3.7fl 

 3.64 



(The other two analyses appended for comparison were not known tc 

 Dr. Parsons until after he had finished his. The one made at the Uni 

 versity of Virginia was under Professor Mallett's supervision, and can 

 be seen in London Chemical News, No. 882, p. 168.) 



The most notable peculiarities of this substance are, the entire absence 

 of starch ("No fungus has yet been found to contain true starch." — 

 Sach's "Botany," p. 241), the comparatively small amounts extracted by 

 solvents, the gelatinous character of the cellulose, and the very small 

 amount of albuminous substance. Nothing else yet analyzed has been 

 reported to contain so large a proportion of pectinous matter. In ordi- 

 nary fruits, such as are commonly used for making jellies, these pectin 



