THE SYNTHESIS OF STARCH. J 57 



astonisliingly slow and insignificant in comparison with the tremendous progress in otitcr 

 lines of chemical investigation, and largely because of the violent methods generally 

 employed in such work. Through ignorance or misconception of the processes in animals 

 and plants the chemist was led too far away from the methods of Nature, but owing prima- 

 rily to the basic work of Croft Hill the way has been opened for an endless amoiuit of 

 investigation which must bring results of incalculable value in the explanation of proto- 

 plasmic processes. 



Apart from the work of Wohler, it seems that it was the discovery of Butlerow (Ann. d. 

 Chem. u. Phar., 1861, cxx, 195; Compt. rend., 1861, liii, 145) that a saccharine substance 

 (methylenitan, C7H17O0) could be formed by the reaction of a solution of trioxylmethylene 

 and lime-water, that led to Bayer's important statement (Ber. d. d. chem. Gesellsch., 

 1870, III, 68) that formaldehyde may be formed from carbon dioxide and water, and that 

 theoretically bj^ the polymerization of 6 molecules of formaldehyde there woidd result a 

 liexose. Various more or less important modifications of Bayer's hypothesis and conceptions 

 have been suggested, particularly by Erlenmeyer (Ber. d. d. chem. Gesellsch., 1877, x, 634), 

 Bach (Compt. rend., 1893, cxvi, 1145, 1389; 1898, cxxv, 479), Pollacci (Bot. Centralbl., 

 1904, xcv, 425, and xcvi, 473; 1905, xcviii, 247), and Usher and Priestly (Proc. Roy. Soc, 

 1905-06, Lxxvii, B, 369; 1906, lxxviii, B, 318). Since Bayer's investigations, interest 

 has been aroused as to whether or not formaldehyde is to be regarded as a primary assimi- 

 lative product; whether formaldehyde can be formed from carbon dioxide and water m 

 vitro; whether sugar can be produced from formaldehyde in vitro; whether a plant can thrive 

 and take up formaldehyde from its ambient medium ; and whether connection can be t raced 

 between formaldehyde and the synthesis of sugar, dextrin, starch, and glycogen in the plant. 



Associated with these inquiries studies have been made, both in the plant and in 

 vitro, in connection with the various saccharine and dextrinous substances which are con- 

 ceived to represent the main bodies in the analyses and syntheses of starch and glycogen. 

 The mere fact that during the syntheses of starch or glycogen there are present intermediate 

 bodies between carbon dioxide and water on the one hand and these polysaccharoses on 

 the other, does not prove of course that such intermediate substances are utilized in the syn- 

 theses, or that starch might not be formed at a single step from carbon dioxide and water, 

 or that because of their seeming absence they may not actually be necessary and that they 

 are niatle and instantly transformed; but the fact that a serial decomposition occiu's in the 

 organism and in vitro, and that the intermediate bodies formed during analysis corre- 

 spond with those found in plants during the syntheses of polysaccharoses, is strong e^'idence 

 of the formation of starch by the protluction of a definitely related series of intermediate 

 bodies which show progressively higher and higher molecular weight and complexity of 

 structure, and that such intermediate bodies as are found in plants may be regarded as 

 representing specific steps in analysis or synthesis, in accordance with whether the plant 

 is consuming or making starch or glycogen. 



If, therefore, formaldehyde can be formed in vitro from carbon dioxide, and sugar 

 formed from formaldehyde, and if at the same time it can be shown that in the plant 

 carbon dioxide and water are primary substances in synthesis, and that formaldehyde is 

 a normal constituent of plants, and that a plant may thrive in a solution or in an atmosphere 

 containing appreciable quantities of formaldehyde and even assimilate this substance, it 

 seems that we have reached the point where it is not a question as to whether or not for- 

 maldehyde is a primary assimilative substance and an intermediate body in the synthesis 

 of certain saccharoses, but to seek for the evidence to prove it. 



Attempts to produce formaldehyde in vitro from carbon dioxide and M'ater were made 

 by Maly (Ann. d. Chem. u. Pharm., 1865, cxxxv, 119), Royer (Compt. rend., 1870, lxx, 

 731), Bach (Compt. rend., 1893, cxvi, 1145, 1389; Chem. Centralbl., 1898, 11, 42), Lieben 

 (Ann. d. Phys. u. Chem., 1895, xix, 463), Cohen and Jahn (Ber. d. d. chem. Gesellsch., 



