Investigation of the Scientific and Economic Relations of the Sorghum Sugar Industry: Being a Report Made in Response to a Request From the Hon. George B. Loring (1883)

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CONCLUSION. SUMMARY OF RESULTS ALREADY OBTAINED AT THE DEPARTMENT OF AaRIGULTURE IN WASHINGTON, D. C., AND ELSEWHERE IN 1HE UNITED STATES, IN THE PROD VCTION OF SUGAR AND MOLASSES FROM SORGHUM AND THE STALKS OF MAIZE* The Committee find, as the result of their investigation, by all the data which have come before them, as well as those obtained by the Department of Agriculture during the years from 1878 to 1882, both inclusive, and those derived from other parties in different sections of the United States, that the following points are established by an amount of investigation in the laboratory, and of practical experience in the field and factory, which have rarely been devoted to the solution of any industrial problem. The more important and well-established results are here enumerated, and are followed by a statement of certain practical and scientific points which still remain for future inquiry. A.—OF THE POINTS ALREADY SETTLED. 1.—THE PRESENCE OF SUGAR IN THE JUICES OF SOEGHUM AND MAIZE STALKS. From records examined by this Committee, it appears that, during the three years prior to 1882, there have been made at the Department of Agriculture almost four thousand five hundred chemical analyses of the juices of about forty varieties of sorghum and of twelve varieties of maize. These analyses have shown the constitution of the juices of each variety at the successive stages in the development of the grow- ing plant. They not only confirm the well-known fact of the presence of sugar in the juices of these plants in notable quantity, but they also establish beyond cavil, what seems surprising to those who have not examined the facts, that the sorghum particularly, holds in its juices, when taken at the proper stage of development, about as much cane- sugar as the best sugar-cane of tropical regions. An examination of the analytical tables in the reports of Dr. Collier, synopses of which follow, will show that the juices of sorghum in cer- tain exceptional, but not isolated, cases were remarkable for the amount of cane-sugar they contained, viz: Of true crystallizable sugar in the juice— Per oeat 5 analyses of five varieties gave over 19 3 analyses of 17 varieties gave over 18 79 analyses of 23 varieties gave over 17 152 analyses of 30 varieties gave over _ 16 * Even at the risk of repeating some statements already made in the earlier por- tions of this report, the Committee consider it is better to review systematically in this summary the whole ground they Have gone over. 43

44 SORGHUM SUGAR INDUSTRY. As compared with the juices of sugar-cane, which gave by analysis under 15 per cent. of sugar, these results are unexpected and surprising. But the average results obtained during long periods of working and from different varieties are of more value to the practical farmer than any exceptional instances. The average results obtained from 122 analyses of 35 different varie- ties of sorghum, and during a working period of one or another of the above varieties of at least three months in the latitude of Washington, are as follows: Average results of analyses of juices of 35 varieties of sorghum. i. n 3. Average. 15.99 1.-84 3.01 11.14 15.94 1.72 3.20 11.02 58.95 1.081 37 16.61 1.83 3.01 11.77 56.51 1.081 45 16.18 1.80 3.08 11.30 58.57 1.0813 182 do Solids do .. . do 60.25 1.082 40 From this statement it will be seen that, as an average of all the analyses made during those three stages, there was obtained 58.57 per cent. of the weight of the stripped stalks in juice; that 16.18 per cent. of the weight of this juice was crystallizable cane-sugar; and that 11.30 per cent. of the weight of the juice may be obtained as sugar by the ordinary process of manufacture.* By reference to the tables it will also be seen that of the eight varie- ties of maize examined in 1881, seven of which were of common field and one of sweet corn— Per cent. of cane-sujrar. 3 analyses of 3 varieties gave over 13 9 analyses of 7 varieties gave over . 12 22 analyses of 7 varieties gave over 11 29 analyses of 7 varieties gave over 10 35 analyses of 7 varieties gave over 9 Of ten varieties of maize grown in 1880, the following results were obtained: Per cent. of cane-sugar. 124 analyses of 10 varieties gave over 9 90 analyses of 16 varieties gave over 10 59 analyses of 9 varieties gave over 11 24 analyses of 9 varieties gave over 12 8 analyses of 4 varieties gave over 13 2 analyses of 1 variety gave over 14 1 analysis of 1 variety gave over 15 In 1880 over sixty-two millions acres of our land were in maize, or 38 per cent. of all the cultivated land of the United States. The amount of sugar thus apparently lost, calculated on the results obtained at the Department of Agriculture in the last three years, is equal to the pres- ent product of the entire world. It is premature to say that the protit- * The " available sugar" here stated is the amount of cane-sugar shown by analysis, less the sum of the glucose and solids not sugar; e. g., in this case 16.18 per cent. less 1.80 per cent. + 3.08 per cent. = 11.30 per cent. This mode of computation as has already been explained, gives a less probable quantity of available sugar thau is shown by the/ method of "exponent," usually used by sugar-boilers.

SORGHUM SUGAR INDUSTRY. 45 able extraction of sugar from corn-stalks is demonstrated, but such a result may yet be possible.* 2.—PRACTICALLY LITTLE DIFFERENCE IN THE VARIETIES OF SOR- GHUM AS TO THEIR CONTENT OF SUGAR. The results of the investigations at the Department of Agriculture have shown the remarkable uniformity of the several varieties of sor- ghum as sugar-producing plants when fully developed; and have also shown the different varieties to vary widely in the time required for their full development, varying, as has been shown, year after year fully three months as between the earlier and later maturing varieties. Tnis fact of the wide variation in the different varieties in their period of reaching full maturity, although previously recognized, has not re- ceived the consideration which its extreme importance demanded, as is evinced by the fact that at present, as for the past thirty years, those varieties are largely grown in the Northern States which could only reach maturity at rare intervals and in exceptional seasons in these lati- tudes. This satisfactorily accounts for the occasional production of crystallizable sirups, and the general failure to secure similar results continuously. 3.—WHEN THE MAXIMUM CONTENT OF SUGAR is PRESENT IN THE SORGHUM. No conclusion established by the work of the Department of Agri- culture, practically considered, is of greater importance than the posi- tive ascertainment of that period in the development of the several varieties of sorghum when their juices contain the maximum of cane- sugar. 4.—CONFLICTING TESTIMONY BEFORE THIS INVESTIGATION. On this point there has existed, during the past twenty years or more, the greatest discrepancy in statement, and the general opinion prevailing has been very wide of the truth, as established by all these experiments. As evidence of the great diversity of opinion concerning this impor- tant matter which existed previous to the experiments at Washington, the following quotations are made from the reports of various experi- menters: a. In his report on "Early Amber Cane," by Dr. C. A. Goessmann, of Amherst, Mass., 1879, he says, p. 9: The safest way to secure the full benefit of the Early Amber Cane crop for sirup and sugar manufacture is to begin cutting the canes when the seed is full grown, yet *till soft.) * The only trial on a large scale for extracting sugar from corn-stalks of which we have record will be found in the statement of J. B. Thoms, of date April 10, appended to this Report (p. 119), and was not a success. It is possible that if the maize had been allowed to mature, in place of being cut when the ear was in an immature state fit for canning, the result might have been different. t Dr. Goessmanu's statement requires the modification as explained by him in Com- mittee, viz: To secure the crop (some 20 acres of land), it was essential, with the limited milling power a.t his command, to commence milling at the time specified, even if some loss of cane-sugar followed this course.

46 SORGHUM SUGAR INDUSTRY. b. In the " Sorgo Hand Book," published by the Blymyer Manufact- uring Company, Cincinnati, Ohio, 1880, it is directed upon page 8: The cane should be cut when the seed is in the dough, and several days before grinding, as it will be more free from impurities if cured for a few days before going to the mill. c. In a pamphlet entitled " Sugar-making from Sorghum," published by the Clough Refining Company, p. 5, directions are given to— Harvest as soon as the seeds begin to form, aud before they get hard. Grind the cane, if possible, soon after it is out. d. In a pamphlet entitled " The Sorgo Manufacturers' Manual," by Jacobs Brothers, Columbus, Ohio, p. 4,1866, it is stated that— The cane is in the best state for harvesting when part of the seed is beginning- to turn black, or in other words, when the seed is in a doughy state. The cane should be out and shocked in the field with tops on, and in this condition it may remain several months before being worked up, for the cane matures aud forms more saccharine matter. e. In a " Report on the Manufacture of Sugar, Sirup, and Glucose from Sorghum," by Professors Weber and Scovell, of the Illinois Indus- trial University, 1881, p. 22, they say: The proper time to begin cutting the cane for making sugar is when the seed is in the hardening dough. The cane should be worked up as soon as possible after cutting. /. J. Stanton Gould, in a " Report on Sorghum Culture," made to the New York State Agricultural Society in 1863, p. 752, says: The seed of the cane (sorghum) continues in the dough for about a week. It is the general impression the cane should be cut during this period, as it is then supposed to have the greatest amount of saccharine matter; at least, this is thought to be true of all the varieties except the White Imphee, which is usually cutjitst as it is going out of the milk or just entering the dough. g. In conclusion, we quote from Mr. Gould's paper, as illustrating the chaotic state in which our knowledge was prior to the work at the Department of Agriculture. Upon p. 740 he says: These conflicting opinions might easily be reconciled by a few well-directed experi- ments. Again, he says, same page: After the most careful inquiry, orally and by letter, I am unable to find that any such experiments have ever been made. Again, he says, p. 747: These experiments are not conclusive, and the whole question needs a careful and accurate investigation. As the result of such an investigation, we call attention to the average results of the past years, as shown in the tables accompanying this report, from which it will be seen that during each of the past three years it has been demonstrated beyond any reasonable doubt that the value of the sorghum for the production of sugar increased, upon an average of the 35 or 37 varieties tested, fully 500 per cent., and in many cases 1,000 percent., after the period when, according to the authorities cited, it was recommended that the crop should be cut up.* * MAY, 1883.—The references in the text to "the tables accompanying this report" were made originally upon the expectation that the full text of the documents refer- red to the Academy by the Commissioner of Agriculture would be reproduced as a part of this Report, as well, also, as the " Graphical Charts," essential to a full understand- ing of the results upon which this Report is based. The restrictions imposed by the terms of the Senate's resolution of March 3, 1883, seriously impairs the value of this Report as a Sorghum Manual, by suppressing th« documents in question, with their illustrations. Of the Departmpnt's Report for I8??, ;in edition of :SOO.OOU copies has

SORGHUM SUGAR INDUSTRY. 47 It will be observed also how completely at variance the above quoted authorities are in reference to the subsequent treatment of the crop after cutting it up, the one recommending that it be stored, even for months; the other, that it be immediately worked up. The importance of this latter course of treatment can hardly be overestimated, as appears from data herewith presented. 5.—THE IMPORTANCE OP AN EVEN CROP, WITH NO SUCKERS, IN THE PRODUCTION OF SUGAR. The experiments at the Department of Agriculture this past season have fully confirmed the practical wisdom of a course which is pursued by the sugar planters of Louisiana and Cuba, viz, the exclusion from the matured crop of all immature canes, if the production of sugar is contemplated. ' " BBflCE to*BBflfiF This point, if previously recognized by sorghum growers, has never been properly understood and considered as it deserves to be. 6.—THE IMPORTANCE OF PROMPTLY WORKING THE CROP AFTER IT HAS BEEN CUT UP. To this point also reference has been made already. Its importance can hardly be overstated. If departure from this rule is at any time admissible, it is at least safe to say that the conditions which would warrant such departure are as yet not determined. Prompt working of the cane so soon as cut is always safe, and any delay is fraught with unavoidable risk of loss. This conclusion is established, as well by the work of Dr. Goessmann as by that of the Department of Agriculture. 7.—^UGAR HAS BEEN MADE FROM SORGHUM AND CORN-STALKS. It will be seen from the reports of the past three years at the Depart- ment of Agriculture, as well as from a wide range of experience else- where, that sugar in large quantities has been shown to be present in the juices of sorghum and maize. Also, which is of the first impor- tance from the economical side, high-grade marketable sugar in con- been printed. Of the earlier reports, containing Dr. Collier's results on sorghum, it is understood the editions are exhausted, including Special Report No. 33.—[COM- MITTEE. ] The Senate's resolution, above referred to, is as follows: IN THE SENATE OP THE UNITED STATES, March 2, 1883. Resolved by the Senate (the Souse of Representatives concurring), That the Report of the National Academy of Sciences on the sorghum sugar industry be printed with such portions of the appendix and accompanying exhibits as may be selected by the Joint Committee on Public Printing, and that there be printed 6,500 additional copies, of which 2,000 copies shall be for the use of the Senate, 3,000 copies for the use of the House of Representatives, 1,000 copies for the use of the Department of Agriculture, and 500 copies for the use of said National Academy of Sciences. Attest: F. E. SHOBER, Acting Secretary. IN THE HOUSE OF REPRESENTATIVES, March 3, 1883. Resolved, That the House concur in the above resolution of the Senate. Attest: ED. McPHERSON, Clerk.

48 SORGHUM SUGAR INDUSTRY. siderable quantity has been successfully made at various places, as already cited, from sorghum juice, comparing favorably with the sugar from the true sugar-cane or from the sugar-beet. The testimony of the sugar boiler at the Department of Agriculture who worked up the sorghum in 1881, and who produced a sugar which. polarized 97.5 per cent., is of especial value. He says in his report that " sugar of this character could have been produced day after day from. sorghum such as produced this"; and also, in reference to this sorghum, he testifies " it was only fairly good."—(Vide report 1881-'82, Peter Lynch.) It will be seen that in successive years there was also obtained from the stalks of common maize, after the ripened grain had been plucked, at the rate of 900 pounds of sugar to the acre. It also appears from the correspondence submitted that many parties have practically se- cured results nearly equal to these in their work. 8.—THE HYDROMETER AND RIPE SEED SUFFICIENT TO INDICATE THE PROPER TIME FOR WORKING UP THE CROP. It will be seen by reference to the reports of the work at Washington that it is within the means of the common farmer to inform himself ac- curately as to the condition of his crop by simply examining the seed, and by the hydrometer learning the specific gravity of the expressed juice.* By reference to the preceding reports of the Department of Agricult- ure it will be seen that for each increase of .001 in specific gravity be- tween 1048 and 1086 in the year 1880 there was an average increase (glucose excepted) in the several constituents of the juice of the several sorghums as follows: Per cent. Sucrose ^ 251 Solids 067 Available sugar „ 257 Glucose minus.. .073 Number of analyses, 2,186. In 1881 the increase for each .001 specific gravity was, in the average results, as follows, for specific gravity between 1052 and 1082: Per cent. Sucrose 305 Solids 013 Available sugar 354 Glucose minus.. .062 Number of analyses, 438. The general average for the years 1879,1880, and 1881, specific grav- ity between 1048 and 1080, was as follows for each increase of .001 specific gravity: Per cent. Sucrose 238 Solids 028 Available sugar 262 Glucose minus.. .052 Number of analyses, 2,960. * The Committee do not wish to be understood as advising every farmer to be his own sugar boiler. While it is probably quite true that with very simple means and moderate skill good crystallizable sirup may be made on the farm, it is clear that the skill and experience of a professional sugar-master is essential to the successful man- agement of the trains and vacuum-pans of a well-ordered sugar-house, and the nat- ural result will be, beyond doubt, that such establishments will be set up at con- venient points in each sugar-producing district. The problem, as far as it relates to the production of sirups, appears to be already solved by abundant experience.

SORGHUM SUGAR INDUSTRY. 49 For changes in specific gravity in successive stages of development, each increase of .001 specific gravity corresponded to the following re- sults : * Specific gravity. Sucrose. Solids. Available sugar. Glucose. Number of analyses. 1018tol029 Per cent. .066 Per cent. .016 Per cent. -. 034 Per cent. .084 14& 1029 to 1042 122 025 .069 .028 191 1042 to 1052 .290 .011 .062 .017 129' 1052 to 1061 . .299 .010 .340 —.051 158. 1061tol071 .273 .023 .305 -.055 137 1071 to 1082 317 .011 .371 .065 23«^ From these it will appear that the sorghum juices, after they have reached a specific gravity of about 1050, increase gradually and with great regularity in saccharine strength and in available sugar until a specific gravity of 1080 to 1082 is attained, and that this increase is fully, upon the average, 0.3 per cent. of the weight of the juice for each .001 increase in specific gravity, or an average increase between 1050' and 1082 of 9.6 per cent. of the weight of the juice in available sugar- The practical importance of this fact, which appears to be demon- strated by the very numerous analyses made during the past three years, can hardly be too strongly emphasized. By reference, then, to the table given upou page 79, Special Report 33, the farmer may, by simply taking the specific gravity of his sorghum juice, readily estimate the approximate value of the crop for the produc- tion of sugar or sirup. 9.—LENGTH OP PERIOD FOR WORKING SORGHUMS. Reference has already been made to the very great difference existing between the different varieties of sorghum as to the length of time needed for them to reach maturity. It is not known that experiments have been made to determine this difference accurately, until those lately made at the Department of Agriculture. It has also been shown, as already remarked, that those varieties requiring long periods for their complete maturity have been the varieties largely cultivated in the Northern States during the past thirty years. The results given in the Special Report Xo. 33, page 96, Table 96, show not only the number of days from time of planting to complete maturity of each variety, but also the number of days during which the several varieties were in a condition for working in this latitude. By this table the farmer in any section of the country may be able to select such varieties as the nature of his climate will give him reason to believe may be successfully grown; or, if his season permits, he may select several varieties, which, coming to maturity in succession, will enable him to extend his working season, and yet have his cane of each sort in the best condition for sugar or sirup production. Planted, as these several varieties were, side by side in the same soil and on the same day, the comparative results given in the table referred to are fully trustworthy, and could have been secured in no other way. These results are of direct practical value to the sorghum grower, and •were confirmed by the experience of the past season. S. Mis. 51- 4

60 SORGHUM SUGAR INDUSTRY. 10.—EFFECT OF RAIN UPON THE COMPOSITION OF SORGHUM JUICES. The investigation of this question and the results secured offer a good illustration as to the importance of submitting doubtful questions to the test of actual experiment, since it is nearly certain that any one, reason- ing from a priori considerations, would have concluded, and indeed such conclusion has been accepted as established fact, that the effect of rain would be manifest in a diluted juice, and that conversely a pro- longed drought would result in a concentration and diminution of the juice. The results, however, of very many experiments on every variety of sorghum, during the past season, prove the incorrectness of such con- clusions. 11.—THE EFFECT OF FROST UPON SORGHUM. The investigations concerning this question practically reconcile the discordant reports in regard to this matter. It has been shown that when fully matured the sorghum withstands eveu hard frosts without detriment, but that if immature the effect is most disastrous. It is shown also that this disastrous result is due not directly to the effect of the frost, but to the subsequent warm weather, which rapidly induces fermentation with inversion of sugar in the frosted and imma- ture cane. 12.—MANUFACTURE OF SUGAR FROM SORGHUM. From the numerous results given in Dr. Collier's reports, it is obvious that the method of manufacture of sirup was such that nearly all of the sugar present in the juices of the sorghum or maize could be secured in the sirup without inversion. This point is one of especial importance practically, and since the results differ so widely from those of other experimenters, they are entitled to careful consideration. A single experiment of Dr. Goessmann gave from a juice containing 8.16 per cent. sucrose and 3.G1 per cent. glucose a sirup containing 37.48 per cent. sucrose and 37.87 per cent. glucose, or as follows: Juice: Per cent. Sucrose 69.33 Glucose '.30.67 Sirup: Sucrose 47.94 Glucose 52.06 From which it appears that, supposing there was no loss of glucose in the operation of making the sirup, 21.39 per cent. of the sucrose was converted into glucose, or, in other words, 30.85 per cent. of the sucrose in the juice was inverted. If such a result was to follow invariably, no one, we think, would hesitate to accept the following conclusion drawn by Dr. Goessmann from the above experiment, viz: In sight of these facts it will be quite generally conceded that the sugar production from sirup like the above must remain a mere incidental feature in the Amber-Cane industry in our section of the country. In 1879 the average of 24 experiments with the juices of several varie- ties of sorghum and maize, made at the Department of Agriculture (see Annual Report 1879, p. 53), showed that the relative loss of sucrose in the sirup was only 5.35 per cent. of that present in the juice, instead of being, as Dr. Goessmann found, 30.85 per cent. But of far greater importance is the fact brought out in an average of 40 experiments, including all made, that there was an actual loss of only 12.5 per cent. of the cane sugar; i. e., there was secured as sugar in the sirup 87.5 per cent. of all the sugar present in the juice; thus show- ing that even the total loss by defecation. by skimming, and by inversion,