U. S. DEPARTMENT OF AGRICULTURE UlKKAl OF < IIKMISTRY HTLIJ/llN NO. <>5. H. W. WILEY, Chief. PROVISIONAL MKTHODS FOR THE ANALYSIS OF FOODS AIHUTKM HY THK ASSOCIATION OF OFFICIAL AdldCrLTORAL CHEMISTS. NOVE.MBKIi, 14-Ili, 1901. KDITKI) HY H. W. WILKY. SKCKKTAKY, WITH TilK COI.I.AHOKATION OF W. I). BIGKLOW, HKFEKKE ON FOOD ADI-I.TKUATION. WASHINGTON: GOVERN MM XT IMMNTIN'c; OFFICE. 1 902; U..S. DEPARTMENT OF AGRICULTURE. BUREAU OF CHEMISTRY— BULLETIN NO. 05. H. W. WILEY, Chief. PROVISIONAL METHODS FOK THE ANALYSIS OF FOODS A DOITED BY THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS, NOVEMBER 14-16, 1901, EDITED BY H. W. WILEY, SECRETARY, WITH THE COLLABORATION OF W. D. BIGELOW, REFEREE ON FOOD ADULTERATION. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1903- if LETTER OF TRAXSMITTAL U. S. DEPARTMENT OF AGRICULTURE, BUREAU OF CHEMISTRY, Washington, D. C., January 7, 1902. SIR: I have the honor to submit for your inspection and approval the manuscript of the Provisional Methods of the Association of Official Agricultural Chemists for the Analysis of Foods, with the rec- ommendation that it be published as Bulletin No. 65 of the Bureau of Chemistry. H. W. WILEY, Chief of the Bureau of Chemistry and Secretary of the Association of Official Agricultural Chemists. Hon. JAMES WILSON, Secretary of Agriculture. 2 CONTENTS. Page. Meat and meat products. By W. D. BIGELOW, in charge of food laboratory, Bureau of Chemistry, United States Department of Agriculture 7 Edible oils and fats. By L. M. TOLMAN, Bureau of Chemistry, United States Department of Agriculture 20 Dairy products. By J. A. LE CLERC, State experiment station, Geneva, N.Y.. 85 Cereal products. By A. McGiLL, chemist of inland revenue laboratory, Ottawa, Canada 41 Infant and invalid foods. By H. W. WILEY, Chief of Bureau of Chemistry, United States Department of Agriculture 41 Saccharine products. By ALBERT E. LEACH, analyst of State board of health, Boston, Mass 43 Canned vegetables. By L. S. MUNSON, Bureau of Chemistry, United States Department of Agriculture 50 Cocoa and its preparations. By F. T. HARRISON, district analyst, London, Ontario 54 Tea and coffee. By W. H. ELLIS, district analyst, Toronto, Canada 55 Spices. By A. L. WINTON, chemist of State experiment station, New Haven, Conn 55 Vinegar. By WM. FREAR, chemist of £ ':..te experiment station, State College, Pa 62 Flavoring extracts. By A. S. MITCHELL, chemist of State dairy and food com- mission, Milwaukee, Wis 69 Fruits and fruit products. By L. S. MUNSON and L. M. TOLMAN, Bureau of Chemistry, United States Department of Agriculture 74 Fermented and distilled liquors. By W. D. BIGELOW, in charge of food laboratory, Bureau of Chemistry, United States Department of Agriculture. 81 Baking powders and baking-powder chemicals. By A. L. WINTON, chemist of State experiment station, New Haven, Conn 98 Food preservatives. By W. M. ALLEN, State department of agriculture 107 Coloring matter. By L. M. TOLMAN, Bureau of Chemistry, United States Department of Agriculture Ill 3 120891 ILLUSTRATIONS Page. Fig. 1. Zeiss's butyro-refractometer 23 2. Apparatus for the determination of the melting point 30 3. Apparatus for the determination of carbon dioxid in beer 95 4. BromwelPs fusel-oil apparatus 97 5. Knorr's apparatus for the determination of carbon dioxid 99 6. Heidenhain's apparatus for the determination of carbon dioxid 102 7. Minis' apparatus for the determination of carbon dioxid 157 4 INTRODUCTION. At the meeting of the association in 1900 it was decided, at the suggestion of Mr. Kilgore, the retiring president, to divide the subject of food adulteration into a number of general classes, and make a systematic effort to outline methods for their examination. With this in view, the referee in charge of this subject was instructed to secure the cooperation of associate referees, each of whom should prepare methods for the examination of one or more classes of foods. It was recognized that these methods could not all be prepared at once, but it was the desire of the association that a beginning be made, and that the work be prosecuted with as much vigor as possible. The work was immediately organized, and the cooperation of the following associates was secured: W. M. Allen, W. H. Ellis, William Frear, F. T. Harrison, A. E. Leach, J. A. Le Clerc, A. McGill, A. S. Mitchell, L. S. Munson, L. M. Tolman, H. W. Wiley, and A. L. Winton. The reports, when completed, were forwarded to the referee, printed, and distributed to a mailing list of about 250 chemists for sug- gestions and criticisms, and a meeting of the entire committee was convened just before the meeting of the association in November, 1901. The methods as amended at this meeting were reported to the association and adopted provisionally. In several cases the reports which follow are the result of extensive work which was performed largely for the preparation of these methods. In other cases it has only been possible to take up a portion of the subject; and in still other instances it was found necessary to defer reports for another year. On the whole, it may be said that the methods which were presented are more complete than was anticipated. Several who had not expected to make any report until the following year have been able to prepare a creditable outline of their subjects, and all the reports promised for this year have been received. It is considered, however, by those who have the matter in hand, that only a beginning has been made and that experience will indicate numerous changes in the methods which will be advantageous. At the same time the subject is placed in such a position that it may be considered in detail at an earlier date than was expected. The writer desires to express his obligation to all of his associates, and especially to the local associates, Messrs. Munson and Tolman, for their cordial, prompt, and efficient cooperation. W. D. BIGELOW, Referee on Food Adulteration. 5 PROVISIONAL METHODS FOR THE ANALYSIS OF FOODS, ADOPTED BY THE ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS, NOVEMBER 14-16, 1901. I. MEAT AND MEAT PRODUCTS. By W. D. BIGELOW, In Charge of Food Laboratory, Bureau of Chemistry, U. S. Department of Agriculture. A. MEAT. 1. — IDENTIFICATION OF SPECIES. When dealing with large pieces of meat, and especially with fresh meat, the deter- mination of the species of animal from which it was taken is the work of the veterina- rian rather than the chemist, although the data obtained by the latter are often conclusive as to the variety of meat present. The physical appearance of the meat, its luster, grain, compactness, the presence or absence of the marbled appearance due to intermuscular fat, the size and shape of the bones, and the color and consist- ency of the fatty tissue must all be taken into account. Many of these characteristics are destroyed by curing or smoking, and none of them are retained by chopped meat, sausage, potted meat, or other preparations of like nature. In such cases we must depend mainly on the results of chemical examination. The percentage of glycogen, added to the percentage of reducing sugar, is often of value in detecting horse meat in preparations which are supposed to consist of beef. Certain results obtained in the examination of fat separated from the meat by heat or by extraction with organic solvents also afford valuable data. Among the factors which are of value for this purpose may be mentioned the iodin number, melting point, freezing point, index of refraction, and to a less extent the specific gravity, acetyl number, and Maumen4 value." The meat from embryonic animals and from animals killed before they are suitable for food may often be detected by its moist, clammy nature and high water content. 2. — EXAMINATION OF POISONOUS MEAT AND OTHER FOODS. b From a hygienic standpoint the recognition of diseased meat is a matter of prime importance. The inspection of fresh meats for the purpose of detecting animal parasites such as trichime and vegetable parasites such as the lumpy-jaw fungus, the bacillus of tuberculosis, and other disease-producing bacteria, need not concern the analyst. It is only when a food, presumably wholesome, is found to have poisoned one or more individuals that the analyst must, to some degree at least, distinguish between the agents that may play a causative role. The ordinary foods of man are liable to become poisonous from either of the three causes: (1) Trichime in pork, (2) metals, and (3) bacterial products. •See Appendix, p. 1 19. t>The matter under this heading was written for this bulk-tin by Dr. F. G. Novy, of Ann Arbor, Mich. 7 8 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. (a) TRICHINAE. Pork, and sausage containing pork, which has caused sickness should be examined at once for trichinae. a (b) POISONOUS METALS. The poisonous metals arsenic, antimony, tin, lead, copper, and zinc are to be con- sidered. It should be borne in mind, however, that food poisoning from metals is extremely rare compared with the causes mentioned under bacterial products. It is furthermore not uncommon to find minute amounts of tin or lead in canned meats or other canned food, and the accidental development of toxic properties in such canned goods can not stand in any causal relation to such minimal amount of metals. A single small dose of copper, lead, tin, or other metal need not in itself cause any unpleasant effect, but continued dosing with such small amounts may in the end give rise to disturbances. Several instances of this kind may be mentioned. Vaughan, some years ago, found the cattle in a Western mining region to be dying off because the stream from which they drank received the washings from a hydraulic mining camp. An investigation showed that both arsenic and antimony were present in solution as well as in suspension. Again, a garrison stationed on an East Indian island was obliged to use exclusively water stored up in a galvan- ized iron tank, with the result that chronic gastroenteritis developed in nearly every man. The experience with arsenic in beer in Manchester is very recent. Several hundred cases of chronic peripheral neuritis followed the continued use of beer con- taining minute amounts of this poison. On the other hand, acute poisoning from metals added intentionally or by mistake to foods are too well known. The amount of poison in such cases is such as to render the whole matter easy of solution. From what has been said it is evident that poisonous meats could only under the most exceptional conditions owe this property to metals. A chemical examination, beyond revealing the merest traces of such metals as tin or lead, would mean noth- ing. More than that, such an examination requires a relatively large amount of material, and it not infrequently happens that the chemist hastens on with his chem- ical examination, to which he subjects all or nearly all of his material, so that when he attains a negative result scarcely any of the original substance is left for examination along other lines. For the determination of heavy metals, proceed as directed under vegetables (p. 52). (C) BACTERIAL PRODUCTS. The vast majority of all food poisonings are due to the invasion of the food by bac- teria. The mere fact that bacteria are present in a meat is not evidence that such food is poisonous. Many, in fact most, of the bacteria which invade food are incapable of producing poisons, but they may grow and multiply and give rise to observable decom- position changes. Such changes can be spoken of as simple decomposition due to invasion by nonpoisonous bacteria. When, however, poison-producing germs develop in the meat, then as food it becomes poisonous. It is a noteworthy fact that a food may be highly poisonous without any visible indication of decomposition. In other words, odor and taste are not always reliable guides as to the innocuousness of a food. The toxicogenic germ present in a food may be such that it can not grow in the body, and hence it is obvious that the poisonous effects which are observed are due to the poison which the germ had elaborated while growing in the meat. Such poisonings are pure intoxications. Another type of germ not only grows in the meat where it makes some poison, but it can also grow in the body, and as a result it con- tinues to elaborate such poison for some time after being ingested. And, lastly, a germ may be present which can not grow at ordinary temperature, but does grow in the »Fisch6der, Leitfaden der praktischen Fleischbeschau; Ostertag, Handbuch der Fleischbeschau; Walley, A Practical Guide to Meat Inspection. MEAT AND MEAT PRODUCTS. 9 body, in which case the poisoning is a true infection. Instances are known where diseases of animals have been transmitted by eating the flesh. In view of the fact that bacteria are, above all, the most common cause of poisonous meat, it follows that the examination should primarily be made from that stand- point. To sum up what has already been said: Given a poisonous meat, the first pro- cedure is to detect or exclude the presence of trichinae. If they are not found, the bacteriological examination should next be undertaken, and the chemical examina- tion should be reserved until the last. The bacteriological examination should first consist in feeding a number of different species of animals^— the larger the number the better — for a day or two exclusively upon the food. White mice, house mice, white rats, young dogs, cats, rabbits, or guinea pigs can be used. If the animals sicken and die they are to be subsequently examined for the presence of pathogenic bacteria. It may happen that none of the animals thus fed will be injured by the food, which fact would not exclude, how- ever, the presence of a germ requiring a specially susceptible animal for a subject. Another set of animals should be injected with a cold extract of the meat made with sterile water. If the animals die, they are to be examined for pathogenic bac- teria. A third set of animals should receive similar injections, though of larger por- tions, of this aqueous extract which has been previously filtered through sterile porcelain. If the animals die from such injections the same as with unfiltered solu- tions, it is evident that a soluble bacterial chemical poison is present. The identification of the toxin or real poison produced by the germ is wholly out of the question. The most that can be done satisfactorily is to obtain,* as above, a germ-free solution of the poison. It is wholly unnecessary to devote any space in this connection to the detection of the basic bacterial products, the ptomains, since these bodies are mere cleavage products produced by some and not by other bacteria. Moreover, they are usually but very feebly poisonous, and for that reason they do not hold the prominent position formerly ascribed to them a. A bacteriological examination proper should be made of the original poisonous meat and of all the animals that died cither from outing the meat or from the injec- tions of the aqueous extracts. The organism present in the animal, if any, must be isolable directly from the meat. If it happens, as it sometimes has, that the dead animals contain no germs, it is proof that they were killed by u toxin elaborated by a germ in the meat previous to the injection. Cultures from the meat will then reveal the germ, and the effects of its pure cultures should correspond to those observed with the poisonous meat. To prepare the cultures from the original food, the latter should be cut out with a sterile knife and material should be taken from the inside, thus avoiding all chances of contamination. Several sets of beef-tea tubes and agar plates should be made. One set should be set aside in a Novy anaerobic jar at room temperature; a second similar set should be placed at a temperature of 37° C. A third set should be grown in the presence of air at room temperature, and a like set at a temperature of 37°. The full details of bacteriological methods must obviously be omitted in this con- nection. Such work requires a special laboratory and special drill. Those who may be further interested are referred to the works of Abbott, Novy, and Sternberg. 3. — PREPARATION OF SAMPLE FOR CHEMICAL EXAMINATION. In the case of fresh meat, separate the sample as completely as possible from the bones and pass it rapidly and repeatedly through a sausage mill until thorough mixture and complete maceration are obtained. The sample must be kept on ice to prevent decomposition, and all of the determinations should be begun as soon as practicable after the sample is prepared. In the case of canned meats, pass the •For detailed methods see Vaughan and Novy, "Cellular Toxins," 4th edition, 1902. 10 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. entire contents of a can through a sausage mill as directed above. Remove sausage from the casings and mix by repeated grinding in a sausage mill. Dry that portion of the sample which is not needed for analysis, extract with gasoline which boils below 60° C, allow the gasoline to evaporate spontaneously, and expel the last traces by heating for a short time on the steam bath. Neither the meat nor the separated fat should be heated longer than necessary, owing to the tendency of the latter to decompose. Reserve the fat for examination according to the methods given under the examination of edible fats and oils (page 20) . Fat must be kept in a cool place, and its examination finished before it becomes rancid. 4. — DETERMINATION OF WATER. a Dry to constant weight about 2 grams of the macerated sample, in a tared, flat- bottomed dish ac the temperature of boiling water. The dish may be of aluminum or platinum, or a tin bottle cap answers admirably for this purpose. On account of the oxidation of the fat, meats may be dried to advantage in a current of hydrogen or -in vacuo, although satisfactory results are obtained in the above way. Drying usually requires about five hours. 5. — DETERMINATION OF ASH. a Ignite the residue from the determination of water to low redness as long as smoke or inflammable gases are given off. Exhaust the charred mass with 5 or 10 cc of water, transfer to a filter, and wash with hot water till the greater part of the soluble salts are removed. Transfer filter paper and contents to the original dish and ignite at bright red heat till combustion is complete (a white ash can rarely be obtained) . Transfer the soluble portion to the dish, add a few drops of ammonium-carbonate solution, evaporate to dryness, heat for a moment in a free flame to very low redness, cool in a desiccator and weigh. Satisfactory results may often be obtained without exhaustion by igniting 0.5 gram of the substance in a porcelain crucible cover. 6. — DETERMINATION OF ETHER EXTRACT. It has recently been shown that fat can not be completely extracted from meat by means of ether. A complete extraction can be obtained only after digesting the pro- teids and muscular tissue with pepsin and extracting again with an organic solvent. Voitb extracts first with alcohol, to remove the last traces of water, and then with ether in a continuous extractor. This process leaves ^ery little fat in the sample. Comparative results which are satisfactory in all ordinary examinations of meat may be obtained by extracting 2 grams of the dried,- finely divided sample with ether for 16 hours in a continuous extractor. Fat may be determined by extracting the ether extract with low boiling-point petroleum ether. 7. — DETERMINATION OF NITROGENOUS SUBSTANCES. (a) TOTAL NITROGEN. Employ either the Kjeldahl or the Gunning method, using about 2 grams of the sample. The digestion with sulphuric acid should be continued at least 4 hours. (b) COAGULATED PROTEIDS. Thoroughly exhaust 2 grams of the sample with cold water after extraction with ether, filter, and determine nitrogen in the insoluble residue as directed under " Total nitrogen." Multiply the percentage of nitrogen so obtained by 6.25 for the percent- » See Appendix, p. 149. b Ztschr. f. Biol., 1897, 35, 555. MEAT AND MEAT PRODUCTS. 11 age of meat fiber or coagulated proteids. (In case the connective tissue is deter- mined, a corresponding correction must be made in the percentage of coagulated proteids.) (c) DETERMINATION OF CONNECTIVE TISSUE. Extract 10 grams of the sample with cold water as directed above, then boil the exhausted residue repeatedly with about 100 cc of water until the total extract amounts to about 1 liter. Filter the extract, concentrate by evaporation, and deter- mine the nitrogen content. Multiply the nitrogen so obtained by 5.55 for the per- centage of nitrogenous substances of connective tissue. (d) DETERMINATION OF COAGULABLE PROTEIDS (FOR UNCOOKED MEAT ONLY). Almost neutralize the filtrate from the coagulated proteids, leaving it still faintly acid, boil until the globulins are coagulated, filter, wash, transfer the filter paper and contents to a Kjeldahl flask, and determine nitrogen as directed above under "Total nitrogen." Multiply the percentage of nitrogen obtained by 6.25 for the percentage of coagulable proteids. (e) DETERMINATION OF PROTEOSES, PEPTONES, AND GELATIN. (1) First method. This is a combination of Bomer'sa method with that of Allen and Searle,1' as mod- ified by Wiley.0 Evaporate the filtrate from the globulins to small volume, add 2 or 3 drops of 1-3 sulphuric acid, and saturate with powdered zinc sulphate. The excess of zinc sul- phate added should not be large, as otherwise serious "bumping" is likely to ensue. About 80 grams of the salt are required for each 50 cc of liquid. Allow the coagu- lated proteids to subside, filter, and wash with a saturated solution of zinc sulphate. Acidulate the nitrate from the zinc sulphate precipitate with 2 or 3 drops of strong hydrochloric acid, dilute with an equal volume of water, add about 2 cc of liquid bromin, and shake the contents of the flask vigorously. (This can be most conven- iently done in a Kjeldahl flask. ) If the bromin be all taken up, add more until about 0.5 cc of liquid bromin is left undissolved and the supernatant liquid thor- oughly saturated. Allow the mixture to stand over night, decant the supernatant liquid through a filter paper, and wash with water, so directing the jet that the glob- ule of bromin is stirred up and saturates the wash water. Return the filter paper and precipitate to the flask, add the zinc sulphate precipitate and filter paper con- taining it, and determine the nitrogen as directed under "Total nitrogen." The per- centage of nitrogen so found, multiplied by 6.25, gives the percentage of proteoses, peptones, and gelatin, including gelatin peptone. (2) Second method.'1 Heat the filtrate from albumen and globulins, add a slight excess of tannic acid and a few drops of a saturated solution of alum, allow to cool, filter, and wash with cold water. Heat the filtrate from the tannic-add precipitate almost to boiling, add an excess of phospho-tungstic acid, e separate the precipitated proteids by filtration •Ztschr. anal. Chem., 1895,5,562. b.The Analyst, 1897, 22, 258-263. 0 U. S. Dept. Agr., Div. of Chem., Bui. 54. «» Mallet, U. S. Dept. of Agr., Div. of Chem., Bui. 54. « Mallet employs two solutions, one containing 50 and the other 100 grams of crystalline phospho- duodeci-tungstic acid dissolved in 1 liter of 2i per cent of hydrochloric acid. He also recommends the addition of sand or pulverized glass to prevent the foniDition of the coagulated proteids in a deuso clot. Owing to the liability of "bumping" in the presence of such substamvs. however, during the determination of nitrogen it would seem that such addition should be avoided if possible. 12 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. and wash with hot water, being careful that the temperature of the solution and wash water shall not be less than 90° C. at any time. Transfer the filter papers containing the tannic acid and phospho-tungstic acid precipitates to a Kjeldahl flask and determine nitrogen. The nitrogen so obtained multiplied by 6.25 gives the percentage of proteoses, peptones, and gelatin. (f) DETERMINATION OF MEAT BASES. Deduct from the total nitrogen the sum of the nitrogen obtained in the determina- tion of coagulated proteids, connective tissue, globulin, and proteoses, peptones, and gelatin for the nitrogen of meat bases. Multiply the result by 3.12 for the percentage of meat bases. a 8. — DETERMINATION OF STARCH (FOR CHOPPED MEAT, SAUSAGE, DEVILED MEAT, ETC.). (a) QUALITATIVE DETERMINATION. Treat 5 or 6 grams of the sample with boiling water for two or three minutes; cool the mixture, and test the supernatant liquid with iodin solution. In using this test it must be remembered that a small amount of starch may be present as the result of the use of spices. If a marked reaction is given, however, it may be con- cluded that starch or flour has been added, and a quantitative determination may be made. The above qualitative method may be replaced by a microscopic examina- tion, by which not only the presence of added starch, but also the variety employed, may be determined. (b) QUANTITATIVE DETERMINATION. The official methods of the association for the determination of starch will not answer for the examination of meat because of the presence in meat of bodies which hold a portion of the cuprous oxid in solution, and thus give results which are too low. In this laboratory Munson examined a series of sausages which contained no starchy material except the spices employed in their manufacture. He obtained less reduced copper from the sausages than from the blank determination of reducing bodies in the malt infusion employed. (1) Ambuhl's method.* This method has been adopted by Swiss authorities. It is short and convenient, although the results obtained by it are only roughly approximate. Thoroughly macerate 2 grams c of the meat under examination with fifty times its weight of water. Boil for thirty minutes and dilute to 100 cc for every gram of meat employed. Cool an aliquot portion of the liquid, treat with iodin, and compare the depth of color with solutions containing a known amount of the same kind of starch (the variety of starch in the sample is determined microscopically), and boiled for the same length of time. (2) Mayrhofer's method, d modified by Bigelow. e Treat from 10 to 20 grams of the sample under examination (depending upon the amount of starch indicated by the iodin reaction) in a porcelain dish or casserole witfc 50 cc of an 8 per cent solution of potassium hydroxid and heat the mixture on the water bath until the meat is entirely dissolved. The operation may be hastened by macerating the larger pieces with a glass rod. Add an equal volume of 95 per •See appendix, p. 149. I'Pharm. Centralh., 1881, 22, 438; Abstract Ztschr. anal. Chem., 1882, 21, 486. «Ambuhl directs that from 2 to 10 grains be employed, according to the size of the meat particles. If the sample be macerated, however, as directed under the preparation of sample, it is unnecessary to employ a large amount. •i Forsch. ii, Lebensm., 1896, 3, 141, and 1897, 4, 47. •IT. S. Dept. of Agr., Bureau of Chem. Bui. 13, part 10. MEAT AND MEAT PRODUCTS. 18 cent (by volume) alcohol, mix thoroughly, filter the mixture through an asbestus filter and wash twice with a hot 4 per cent solution of potassium hydroxid in 50 per cent alcohol. Then wash with 50 per cent alcohol until a small portion of the fil- trate does not become turbid upon the addition of acid. Return the precipitate and filter to the original vessel and dissolve the precipitate, with the aid of heat, in 60 cc of a normal solution of potassium hydroxid. In the case of sausage with a hi-rh starch content a somewhat larger volume of alkali may be required. Acidify the filtrate strongly with acetic acid, dilute to a definite volume, thoroughly mix by shaking, filter through a fluted filter, and precipitate the starch from an aliquot part of the filtrate by means of an equal volume of 95 per-cent alcohol (sp. gr. 0.81) . Trans- fer the precipitate to a filter, thoroughly wash with 50 per cent alcohol (by volume), with absolute alcohol, and finally with ether, dry to a constant weight at the tem- perature of boiling water, and weigh. 9. — DETERMINATION OF GLYCOQEN. The determination of glycogen has been suggested a as a means to detect the pres- ence of horse meat. Recent results indicate that this determination is of limited value because of the fact that glycogen begins to disappear soon after the death of the animal and may entirely disappear after a short lapse of time. No definite conclu- sions can therefore be derived from the results of this determination, but it is of value as confirmatory. (a) QUALITATIVE METHOD. b Boil 50 grams of the macerated sample with 50 cc of water for from fifteen to thirty minutes. Filter the broth through a moistened filter paper or piece of fine linen. To a portion of the filtrate in a test tube add a few drops of a reagent composed of 2 parts iodin, 4 parts posassium iodid, and 100 parts water. In the presence of a large percentage of horse meat the glycogen contained produces a dark brown color, which is destroyed by heating and reappears on cooling. When starch is present it may !><• precipitated by two volumes of glacial acetic acid, separated by filtration, and the test for glycogen repeated in the filtrate. (b) QUANTITATIVE METHOD. The methods for the quantitative examination of glycogen are all tedious to the last degree. Fairly satisfactory results may be obtained by the methods of Briicke, c R. Ktilz, rt Pfliiger, e Hay wood, f and Pfliiger and Nerking. * Of these the last has been selected as combining a sufficient degree of accuracy with the greatest simplicity and convenience. Digest 50 grams of finely macerated meat on the water bath with 200 cc of 2 per cent potassium hydroxid until solution is practically complete. Cool the solution, dilute with water to exactly 200 cc, shake and filter. Treat 100 cc of the filtrate with 10 grams of potassium iodid and 1 gram of potassium hydroxid and stir until solution is complete. Add 50 cc of 96 per cent alcohol, and allow to stand until the following day. Then separate the precipitated glycogen by filtration, and wash with a sohil i< >n containing 1 cc of 73 per cent potassium hydroxid, 10 grams of potassium iodid, 100 cc of water, and 50 cc of 96 per cent alcohol (sp. gr. .81). Wash the glycogen with a 1 1 1 i x t tire of two volumes of 96 percent alcohol and one volume of water containing about 7 in-: of sodium chlorid JUT liter, dissolve in water, and remove the remaining traces of proteids by the addition of double iodid of mercury and potassium. It is often » Nii-l.-l. /tsdir. ang. Chem., 1895, 620. bCourlay and Corenmns. Ztsrhr. Ntilir. Ilyjr. Waar., 1896,1O, 173-174. «SitzuiiK*iVr Anid. Wisscnscli.. Wicii, Bd. 63, II abth., 1871, p. 214. '/Ctsrhr. f. Biol., 4, 169. •Arch. K»-S. I'hysiol., 1899, 75, 120-247. Mour. Arn. chi-m. Soc., 1900, ii'i, S5. *Arch. Physiol., 1899, 76, 531-542. 14 PROVISIONAL METHODS FOB ANALYSIS OF FOODS. found that the proteids are so completely removed that no precipitate is formed with the double iodid. In such case nitration is not necessary. Add about 2 mg of sodium chlorid per 100 cc of water, precipitate the glycogen again by means of two volumes of 96 per cent (sp. gr. 0.81) alcohol, filter, wash with 96 per cent alcohol, containing about 7 mg of sodium chlorid per liter, then with absolute alcohol, finally with ether, dry to constant weight, and weigh. As a control, invert the precipitated glycogen by boiling for three hours with hydro- chloric acid diluted with 10 parts of water and determine the reducing sugar by Allihn's method, multiplying the result by 0.9 for percentage of glycogen. 10. — DETERMINATION OF REDUCING SUGAR. Boil 100 grams of the finely divided meat for fifteen or twenty minutes in a 500-cc graduated flask with a convenient volume of water. Add a few cubic centimeters of normal lead acetate, cool to room temperature, make up to mark with water, and filter through a fluted filter. Evaporate to a small volume as large an aliquot portion of the filtrate as possible, add a saturated solution of sodium sulphate, make up to a definite volume, and filter through a fluted filter. Determine sugar in an aliquot portion of the filtrate by the Allihn method (p. 49). 11. — DETERMINATION OF POTASSIUM NITRATE. (a) METHOD OF SCHLOSING-WAGNER. a A flask of about 250-cc capacity is provided with a rubber stopper with two holes. Through one of them is passed the stem of a funnel carrying a glass stopcock. The other carries a delivery tube leading to the receiving vessel. The end of the delivery tube is bent so as to pass easily under the mouth of the measuring burette and is covered with a piece of rubber tubing. Fifty cubic centimeters of saturated ferrous chlorid solution and the same quantity of 10 per cent hydrochloric acid are placed in a flask. The ferrous chlorid solution is prepared by dissolving nails or other small pieces of iron in hot hydrochloric acid and is kept in glass-stoppered flasks of about 50-cc capacity, entirely filled. The contents of one flask is enough for about twelve determinations, and by using the whole content of a flask as soon as possible after opening, all danger of oxidation which would take place in a large flask frequently opened is avoided. The contents of the flask are boiled until all the air is driven off. The delivery tube is then placed under the measuring tube, which is filled with 40 per cent potassium hydroxid, then a few drops of water are added and the tube is covered with a piece of filter paper. By a careful and quick inversion, the measuring tube can be brought into the vessel receiving it without any danger of air entering. One hundred grams of the finely macerated meat are extracted by boiling repeatedly with successive small volumes of water, the aqueous solution is concentrated to a small volume, transferred to the funnel, and, with continued boiling, allowed to pass, drop by drop, into the flask. When almost all has run out, the funnel is washed with three 10-cc portions of 10 per cent hydrochloric acid and these portions are allowed to pass, drop by drop, into the flask; the temperature of the surrounding water will soon be imparted to the contents of the tube, and the volume of nitric oxid is read with the tube in such a position that the level of the water within and without the tube coincide. The amount of nitric oxid present and the corresponding percentage of nitrate may be calculated in the usual way for the given temperature and barometric pressure, or, to avoid computation, the amount of nitrate may be determined by comparison of the »Agr. Chem. Vers. Stat. Halle, i>. 50; Wik-y, Principles and Practice of Agricultural Analysis, vol. 2, p. 228. MEAT AND MEAT PRODUCTS. 15 volume of nitric oxid with that evolved by a definite volume (f> to Id cc) of normal sodium nitrate solution. (b) PHENOL-8ULPHONIC ACID METHOD.* Weigh 1 gram of the sample into a 100-cc flask, add from 20 to 30 cc of water, and heat on the water bath for fifteen or twenty minutes, shaking occasionally. Add 3 cc of a saturated solution of silver sulphate for each per cent of sodium chlorid present, then add 10 cc of lead subacetate and 5 cc of alumina cream, shaking after each addition. Make up to mark with water, and filter through a fluted filter, returning the filtrate to the filter until it runs clear. Evaporate to dryness 25 cc of the filtrate, add 1 cc of phenol-sulphonic acid," mix thoroughly with a glass rod, add 1 cc of water and 3 or 4 drops of concentrated sulphuric acid and heat on a steam bath for two or three minutes, being careful not to raise the temperature sufficiently to char the material. Now add about 25 cc of water and an excess of ammonium hydroxid. Transfer to a 100-cc flask, add 1 or 2 cc alumina cream if not perfectly clear, dilute to mark with water, and filter if necessary. Prepare a number of 50-cc Nessler tubes, preferably the long, narrow tubes, placing in the first 1 cc of the standard nitrate solution, in the second 2 cc, and so on to 10 cc, then 12 cc, 15cc, 18cc,and20 cc. The comparison of the solution under examination with these tubes will show directly if it comes within this range, in which case it can be read by direct comparison with the various tubes till the one of the exact shade is found. If the color of tj^e solution be darker than any of the tubes prepared as above, it is preferable to dilute as many times as may be necessary to bring the color within this range by transferring 25 cc of the solution to another tube with a pipette and filling up to the mark with distilled water. In this case the reading of the diluted solution in cubic centimeters of standard solution should be multiplied by the num- ber of times the solutii >n under comparison has been diluted. More exact comparisons can be made looking sidewise through the tubes toward a window covered with white paper and shaded from direct sunlight. The following table prepared by Mr. Given enables one to determine at a glance the percentage of potassium nitrate in a given sample from the number of cubic centimeters of standard solution employed, if the above directions are followed in detail : Per cent potassium nitrate. Stand- ard so- lution. Per cent KN03. Stand- ard so- lution. Per eenl KN03. Stand- ard so- lution. Per cent KN03. cc cc cc 0.7 0.01 1 1.7 0.21 28.7 0.41 1.4 .02 ir>. i .22 29.4 . 12 2.1 .03 16.1 .23 30.1 .48 2.8 .04 16.8 .24 30.8 . 11 3.5 .05 17.5 .25 31.5 .45 4.2 .06 18.2 . 2( i 32.2 .46 4.9 .07 18.9 .27 32.9 . 17 5.6 .08 19.6 .28 33.6 .48 6.3 .09 20.3 . 21) 34.3 . in 7.0 .10 21.0 .30 35.0 .50 7.7 .11 21.7 .31 35.7 .51 8.4 .12 22.4 .32 3C.4 9.1 .13 23.1 .33 37.1 .53 9.8 .14 23.8 .34 37.8 .54 10.5 .15 24.5 .35 38.5 .55 U.2 .16 25.2 .36 :>'.». 2 . .M; li:9 .17 25.9 .37 39.9 .57 12.6 .18 26.6 .38 40.6 . 58 13.3 .19 27.3 .39 41.3 .59 14.0 .20 28.0 .40 42.0 .60 •Thismethod is a modification of the one ordinarily employed for determining potassium nitrate in water. It was a examination of meat by Mr. Arthur Given. '• Prepared l.y mixing together 37 re of romvnt rated sulphuric acid, 3 cc of distilled water, and <> Kramsof phenol. 16 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. 12. DETECTION OF PRESERVATIVES. The chemical preservatives commonly used with meat products are borax and boric acid and sulphites. Salicylic and benzoic acids are occasionally used, and formaldehyde is said to be used, although the writer has failed to detect- its presence in meat preparations. The general methods for the detection of these preservatives are given on pages 107 and 110. A few special methods are described below. In gen- eral, preservatives may be separated from meat by digesting a few minutes in warm water, made slightly acid or slightly alkaline according as the nature of the pre- servative is basic or acid. (a) BORAX AND BORIC ACID. If present in noticeable amounts, boric acid may be detected in meat products by heating 20 grams of the sample a few minutes in about 100 cc water acidified with 6 or 8 cc of concentrated hydrochloric acid and testing with turmeric paper as directed on page 110. If no action is obtained by this method, about 20 grams of the sample should be made alkaline with calcium hydroxid, ignited, and the ash tested as directed under preservatives. (b) SULPHUROUS ACID. The distillation method for the detection of sulphurous acid (see page 107) will answer for the examination of meat, but mere traces should be ignored. According to Ostertag, a the microscopic examination of meat that has been preserved with sodium or calcium sulphite often discloses the presence of crystals of sodium or calcium sulphate, due to partial oxidation of the sulphite. In the absence of chlorids and nitrates Kiimmerera employs potassium iodate paper in the following manner: Place the sample of meat on potassium iodate paper and moisten it with dilute sulphuric acid (1:8) free from oxids of nitrogen. In the presence of even minute traces of sulphites a deep-blue color is immediately formed, while in the absence of sulphites only a faint-blue color is produced, and that after a considerable time. This method is of limited application, since it can not be used with meats containing salt or saltpeter. 13. DETECTION OF COLORING MATTER.1* Sausages and other preparations in which chopped meat is employed rapidly become discolored on exposure to the air. This change does not take place to a marked extent with meat that has been cured in a pickle containing saltpeter. With fresh chopped meat, and sometimes with corned meat, especially that cured without saltpeter, coloring matter is sometimes added to prevent the change of color which would naturally take place. Aniline dyea and cochineal carmine are ordinarily employed for this purpose, though in some instances vegetable colors have been detected in the form of lakes. The coloring matter may often be extracted by heat- ing for 15 or 20 minutes with 50 per cent alcohol, 50 per cent glycerin slightly acidi- fied, a mixture of alcohol and glycerin, c ammonium hydroxid, or a 5 per cent solu- tion of sodium salicylated in water. Approximately equal weights of meat and solvent may be used. In case the filtered extract by any of these methods is colored red or deep yellow, «it should be evaporated nearly to dryness, slightly acidified with hydrochloric acid, and boiled a few minutes after the addition of a thread of fat free wool. If the wool is dyed, it may be examined as directed by the referee on coloring, matter. If the wool is not dyed, the solution is examined spectroscopically. »Handbuch der Fleischbeschau, 3 ed., p. 826. »> See appendix, p. 149. « Klinger and Bujard, Ztschr. ang. Chem., 1891, 515. * Spaeth, Pharm. Centralh., 1897, 38, 884. MEAT AND MEAT PRODUCTS. 17 If too dilute, the solution may often be concentrated by precipitating the coloring matter as a lake,a allowing it to settle, decanting off the water, dissolving in hydro- chloric acid and making alkaline with ammonia. In extracting with 50 per cent alcohol, the proteids of the meat are coagulated, with the formation of a pale, almost white, color. If the meat is not discolored dur- ing this extraction, it is probable that some foreign color is present. b Marpmannb examines sausages microscopically for the presence of coloring matter after dehydrating with alcohol and xylol consecutively, removing the xylol with car- bon tetrachlorid, and immersing in cedar oil until the natural colors of the meat have disappeared. (B) MEAT EXTRACTS. 1. — PREPARATION OF SAMPLE. Liquid and semiliquid meat extracts and similar preparations should be removed from the container and thoroughly mixed before sampling. With many liquid preparations a sediment is found in the bottom of the container which will be over- looked if great care is not taken. 2. — DETERMINATION OF WATER. Follow directions given on page 10, employing about 2 grams of powdered prepa- rations, about 3 grams of preparations of pasty consistency, and from 5 to 10 grams of liquid extracts, according to the solid contents. Dry the powdered preparations directly without admixture. Dissolve the pasty preparations in water and dry with sufficient ignited asbestos or pumice stone to absorb the solution. Tin or lead dishes or Hofmeister glass dishes, are often convenient with samples in which the residue is to be extracted for fat, as the dishes may be cut or broken and placed in the extraction tube with the sample. 3. — DETERMINATION OF ASH. Proceed as directed on page 10. In case of pasty preparations, add sufficient water to effect solution and evaporate to dryness in order that the solids may be distributed evenly over the bottom of the dish. 4. — DETERMINATION OF FAT. Transfer the residue from the determination of water to the tube of a continuous extraction apparatus, wash any fat adhering to the dish into the tube with ether, and extract with ether sixteen hours. 5. — DETERMINATION OF NITROGENOUS SUBSTANCES. (a) TOTAL NITROGEN. Employ either the Kjeldahl or the Gunning method. (b) DETERMINATION OF MEAT FIBER. ° Dissolve in cold water 5 grams of powdered preparations, from 8 to 10 grams of extracts of pasty consistency, or from 20 to 25 grams of fluid extracts; filter and wash with cold water. Transfer the filter paper and contents to a Kjeldahl llask and determine nitrogen as directed under total nitrogen. In case of a large amount of insoluble matter, make up to a definite volume, filter through a fluted filter paper, •Bremer, Forschungsber., 1897, 4, 46. i>Ztschr. ang. Mikr., 1895, 1, 12. "Allen, Com. Org. Anal., 2d ed.. vol. 4, p. 3:24. ir,«Ms No. 65—02 2 18 PROVISIONAL METHODS FOE ANALYSIS OF FOODS. and determine nitrogen in an aliquot portion of the filtrate; then deduct the per- centage of nitrogen in the total filtrate from the percentage of total nitrogen for the percentage of nitrogen in meat fiber. Multiply the percentage of nitrogen by 6.25 for the percentage of meat fiber. (c) DETERMINATION OF COAGULABLE PROTEIDS. Make the filtrate (as large an aliquot portion as practicable when the nitrogen of meat fiber has been determined by difference) from meat fiber slightly acid (if not already acid), adding acetic acid or sodium hydroxid as may be required, boil for two or three minutes, cool to room temperature, dilute to 500 cc and filter through a fluted filter. a Determine nitrogen in 50 cc of the filtrate by means of the Kjeldahl or Gunning method. Ten times the nitrogen so obtained deducted from the percentage of soluble nitrogen (which in turn is obtained by deducting percentage of nitrogen occurring as meat fiber from the total nitrogen) gives the percentage of nitrogen contained in albumin and globulins. Multiply this figure by 6.25 for the percentage of coagula- ble proteids in the sample. (d) DETERMINATION OF SYNTONIN. Exactly neutralize the filtrate from the determination of coagulable proteids with sodium hydroxid, using litmus as indicator, and allow to stand until the precipi- tate settles. If only a small amount of syntonin is precipitated, it may be separated with an ordinary filter, washed with water, and its nitrogen content determined by means of the Kjeldahl or Gunning method. If present in any considerable quantity, dilute to a definite volume, filter through a fluted filter, and determine nitrogen in 50 cc of the filtrate. The nitrogen thus obtained (calculated to total volume) is deducted from the nitrogen in the filtrate from the globulins for the syntonin nitrogen. This multi- plied by 6.25 gives syntonin. (e) DETERMINATION OF PROTEOSES, PEPTONES, AND GELATIN. b If it be desired to group these bodies together, proceed as directed under (e), page 11, unite the two precipitates and make a single determination of nitrogen. The per- centage of these bodies can not be determined by using aliquot parts and deducting the nitrogen content of the filtrate from the bromin precipitate from that of the filtrate from the determination of syntonin, because of the decomposing effect exerted by bromin on nitrogen compounds. Experiments in this laboratory also indicate that the aliquot portions of the filtrate from the determination of syntonin can not be used separately for the zinc-sulphate precipitate and the bromin precipitate for the same reason. Although bromin precipitates peptones and zinc sulphate does not, Trescot found, in the examination of a large number of meat extracts when working with aliquot portions of the same solution, that more nitrogen was precipi- tated by zinc sulphate than by bromin. (f ) DETERMINATION OF PROTEOSES AND GELATIN. ° Evaporate the filtrate from the determination of syntonin (as large an aliquot por- tion of the filtrate as is practicable when the percentage of syntonin is determined »The filtering and washing of coagulated proteids are always tedious and unsatisfactory and some- times almost impossible. The work is greatly simplified, therefore, bypassing through a fluted filter and employing aliquot parts of the filtrate, as by this means the complete filtration and washing of precipitates is made unnecessary. b Allen, The Analyst, 1897, 22, 258; Com. Org. anal., 2d edition, vol. 4, p. 325. «Bomer, Ztschr. anal. Chem., 1895, 5, 562; also Mallet, U. S. Dept. Agr., Div. of Chem., Bui. 54. MEAT AND MEAT PRODUCTS. 19 by difference, as suggested by the writer) to a small volume and saturate with zin sulphate. About 85 grams of powdered zinc sulphate are necessary for the saturation of 50 cc of the liquid at ordinary laboratory temperature. The liquid must be fully saturated with the salt, but a large excess should be avoided, as it is likely to cause " bumping" in the subsequent determination of nitrogen in the solution. Letstand several hours, filter, and wash the precipitate with saturated zinc sulphate. In case the precipitate is voluminous, which rafrely happens, the mixture maybe made up to a definite volume with saturated zinc sulphate, filtered, the nitrogen may be deter- mined in an aliquot portion of the filtrate, and the nitrogen of the precipitated proteids determined by difference. (g) DETERMINATION OF PEPTONES.* Dilute the filtrate from the zinc-sulphate precipitate of proteoses and gelatin with an equal volume of water, add bromin until a globule of from 0.5 cc to 1 cc remains undissolved after the liquid is saturated, and allow to stand over night. Filter, wash with cold water, directing the jet to the globule of bromin so as to keep the wash water saturated. Transfer the filtered precipitate to a Kjeldahl flask and determine nitrogen. (h) DETERMINATION OF GELATIN. Stutzer's method b modified by Bigelow.0 Boil 10 grams of the sample for a few minutes with water; filter, wash, and evap- orate the filtrate to dryness in a porcelain dish of about 10 cm diameter, after the addition of about 20 grains of sand which has been freed from dust by sifting, and thoroughly ignited. Exhaust the residue with four 100-cc portions of absolute alcohol, and pass the supernatant liquid through an asbestus filter which rests on a porous plate of about 4 cm diameter, in a funnel. The funnel is surrounded by pounded ice and attached to an aspirator, by means of which gentle and gradually increasing suction may be applied. Take care to transfer as little as possible of the insoluble residue to the filter. Then extract the residue repeatedly with 100-cc por- tions of a mixture containing 100 cc of 95 per cent alcohol (sp. gr. 0.81), 300 grams of ice, and 600 grams of cold water, taking care that the temperature shall not exceed 5° C. at any time. Continue the extraction until the various portions of solvent used are entirely colorless. Filter the extract through the funnel employed for the alcohol extract. Finally, return the asbestus filter to the beaker which contains the exhausted residue and thoroughly extract the whole with boiling water. Receive the hot-water extract in a Kjeldahl flask, determine nitrogen, and multiply the percentage of nitrogen so obtained by 5.55 for the percentage of gelatin and gelatin peptone. (i) PROTEOSES. Deduct the nitrogen in the gelatin precipitate (h) from that of the proteose and gelatin precipitate. This multiplied by 6.25 gives the percentage of proteoses. (j) MEAT BASES. Deduct from the total nitrogen (a) the sum of the nitrogen in (b), (c), (d), (f), and (g). Multiply trie difference by 3.12 for meat bases. 6. — DETERMINATION OF GLYCOGEN. Proceed as directed on page 13. 7. — DETECTION OF PRESERVATIVES. Proceed as directed under Preservatives, page 107. •Allen Com. Org. anal, 2nd Ed,, vol. 4, p. 320. bZtschr. anal. Chcni.. ISHD. «4, 568. «U. S. Dcj>t. of A.m., Huivau of Chcm., Bui. 13, Part 10. 20 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. II. EDIBLE OILS AND FATS. By L. M. TOLMAN, Bureau of Chemistry, United States Department of Agriculture. 1. — GENERAL DISCUSSION. In working with oils and fats the same methods of examination largely apply, except in preparation of the sample. The solid fats should first be melted, thoroughly mixed, and then filtered by means of a hot- water funnel or similar apparatus. Samples for the different determinations are taken from this melted homogeneous mass. The specific gravity must be taken at some temperature above the melting point of the fat. The boiling point of water has been largely used, and, although there are inherent errors in such a method, a it probably gives the most satisfactory results for practical work. In the Maumene test, fats require a higher initial temperature than oils. With oils in most cases the sample for analysis requires no preliminary treatment, except that in case of impurities the oil should be filtered. Oil and fat should always be kept in a cool place, otherwise they will soon become rancid, which will affect more or less the physical and chemical constants. b The iodin number decreases with rancidity, while specific gravity, index of refraction, and acetyl value increase. Too much confidence must not be placed in negative results obtained in a single determination, but only upon making a complete quantitative as well as qualitative examination can a reliable judgment of purity be made. Oils and fats being variable mixtures of glycerids of the fatty acids, their phys- ical and chemical constants vary within limits fairly well established from analytical data. However, too much dependence must not be placed upon the more common determinations, as it is easy to make such mixtures of either fats or oils as will satisfy the ordinary requirements as to specific gravity, index of refraction, heat with sul- phuric acid, iodin absorption, and saponification value. The melting point of the fats and the fatty acids is difficult to determine, because they are mixtures of glycerids or acids, substances which have widely varying melt- ing points. A wide difference has resulted from the varied usage of different analysts, and results obtained by exactly the same method are the only ones that are strictly comparable. For fats Wiley's method of determining melting point has been adopted by the Association of Official Agricultural Chemists. For the free fatty acids obviously this will not do, and the capillary tube was chosen as being a method most generally used and giving the most satisfactory results. 2. — DETERMINATION OF SPECIFIC GRAVITY. c (a) DETERMINATION AT 15.5° 0. Determine the specific gravity of oils at 15.5° C. by the use of a pycnometer, West- phal balance, d or accurately graduated hydrometer. e If determined at room temperature, the following formula may be used to calcu- late the specific gravity at 15.5° C. : f G=G/+-00064 (T-15.5 C.). G=sp. gr. at 15.5°. G'=sp. gr. at T. 0.00064= mean correction for 1° C. »E. E. Ewell, U. S. Dept. Agr., Div. Chem., Bui. 62, p. 125. » E.Spaeth, Ztschr. anal. Chem., 1896, 35, 471-493; C. A. Browne, Jour. Am. Chem.Soc., 1899,21, 989-994. c See appendix, p. 149. dC. A. Crampton, U. S. Dept. of Agr., Div. of Chem., Bui. 13, pt. 4, p. 438. • Accurately made hydrometers reading from sp. gr. 0.900 to 0.940 at 15.5° C. will satisfy every require- ment of accuracy and speed. 'Allen, Com. Org. Anal., 3d ed., vol. 2, pt. 1, p. 33: Winton, Conn. Expt. Sta. Kept., pt, 2, 1900, p. 149. EDIBLE OILS AND FATS. 21 This is only approximately correct, as the correction varies for different oils, but will satisfy ordinary requirements. If a higher degree of accuracy is desired, the factors given in the following table may be employed, but to obtain the best results the determination must be made at standard temperature. Factors for calculating specific gravity. a Oil. Correction for 1° C. Observer. Cod-liver oil 0 000646 A.H.Allen. Lard oil .000658 C. M. Wetherill. Olive oil 000629 C. M.Stillvvell. Arachis oil .000655 A.H.Allen. Rape oil . 000620 Do. Sesame oil .000624 Do. Cotton-seed oil .000629 Do. Cocoanut olein .000665 Do. The following table gives correction for solid fats:b Factors for calculating specific gravity. Fats. Correction for 1° C. Cocoa butter 0. 000717 Tallow 000675 Lard .000650 Butter fat .000617 Cocoanut stearins .000674 Cocoanut oil .000642 000657 (b) DETERMINATION AT THE TEMPERATURE OF BOILING WATER. c (1) Standardization of flasks. First method. — Use a small specific gravity flask of from 25 to 30 cc capacity. The flask is to be thoroughly washed with hot water, alcohol, and ether, and then dried. After cooling in a desiccator the weight of the flask and stopper is accurately determined. The flask is filled with freshly boiled and still hot distilled water and placed in a bath of pure distilled water. The water of the bath is kept in brisk ebullition for thirty minutes, any evaporation from the flask being replaced by the addition of boiling distilled water. The stopper, previously heated to 100°, is then inserted, the flask removed, wiped dry, and after it has nearly cooled to room temperature placed in the balance, and weighed when balance temperature is reached. Second method. d — The following formula may be used for calculating the weight of water (WT) which a given flask will hold at T° (weighed in air with brass weights at the temperature of the room) from the weight of water (Wl) (weighed in air with brass weights at the temperature of the room) contained therein at t°: eF=the density of water at T°. d'=the density of water at t°. y=the coefficient of cubical expansion of glass. e » Allen, Com. Org. Anal., 3d ed., vol. 2, pt. 1, p. 33. »> Allen, Com. Org. Anal., 3d.ed., vol. 2, pt. 1, p. 32. «U. S. Dept. of Agr., Div. of Chem., Bui. 46 revised, p. 33. *E. E. Ewell, U. S. Dept. Agr., Div. Chem., Bui. 62, p. 125. •This factor is commonly given as 0.000026, but it varies considerably. Schulze (Ztschr. anal. Chem., 1882, '21, 1C.7-177) found the glass used by him varied from 0.0000288 to 0.0000305; an average of theM- is 0.0000296. Ewell has used 0.000028 in his work, U. S. Dept. of Agr., Div. of Chem., Bui. 62, p. 121. 22 PROVISIONAL METHODS FOE ANALYSIS OF FOODS. (2) Determination. Weight of fat at the temperature of boiling water. — The flask is rinsed with alcohol and ether, and dried for a few minutes at the temperature of boiling water. It is filled with the dry, hot, fresh-filtered fat, which should be entirely free from air bubbles, replaced in the water bath, and kept for thirty minutes at the temperature of boil- ing water. The stopper, previously heated to 100° C, is inserted, the flask removed, wiped dry, placed in the balance after it has nearly cooled to room temperature, and weighed when the balance temperature is reached. The weight of fat having been determined, the specific gravity is obtained by dividing it by the weight of water previously found. Example: Grams. Weight of flask, dry 10. 0197 Weight of flask, plus water 37. 3412 Weight of water 27.3215 Weight of flask, plus fat 34. 6111 Weight of fat 24. 5914 Specific gravity=24.5914H-27.3215=0.90008. The weight of the flask dry and empty may be used constantly if great care be taken in handling and cleaning the apparatus, but the weight of water at boiling temperature must be determined under the barometric conditions prevailing at the time the determination is made. Example: Grams. Weight of flask, dry and empty 10. 0028 Weight of flask after three weeks' use 10. 0030 3. — DETERMINATION OF INDEX OF REFRACTION.* Determine the index of refraction with any standard instrument, oils being read at 15.5° C. and fats at 40° C. The temperature must be controlled with great care, and in accurate work the readings should be taken at standard temperature. The readings of the Zeiss butyro- refractometer can be reduced to standard temperature by following formula:1* R=R'+.55 (T'-T). in which R is the reading reduced to T, R' the reading at Temp. T, T the standard temperature, and .55 the correction for 1° C. in scale divisions. With oils the factor .58 is substituted in the formula for .55, since they have a higher index of refraction. To calculate to standard temperature the readings of the instruments which give index of refraction directly the factor 0.000365 may be used. As the temperature rises the refractive index falls. Example: The refractive index of a butter fat deter- mined at 32.4°C.=1. 4540 is reduced to 25° C., as follows: 32.4— 25=7.4; 0.000365X7.4= 0.0027; it is then 1.4540+0.0027=1.4567. The instrument used should be set with distilled water at 18°C., the theoretical refractive index of water at that temperature being 1.3330. In the determination above given the refractive index of pure water measured 1.3300; hence the above numbers should be corrected for theory by the addition of 0.0030, making the cor- rected index of the butter fat mentioned at the temperature given 1.4597. The index of refraction varies greatly with the specific gravity, increasing as it increases. In abnormal results it is often well to see if the specific refractive power0 •See appendix, p. 150. fcWiley, Prin. and Prac. of Agri. Anal., vol. 3, p. 341. Winton, Conn. Expt. Sta. Kept., 1900, pt. 2, p. 142. « Landolt., Ber., 1882, lo, 1031. C. A. Browne, Jour. Am. Chem. Soc., 1899, 21, 991. EDIBLE OILS AND FATS. 23 is different from the normal. Calculate the specific refractive power from the N i a formula ^ > in which N equals the refractive index and D the specific gravity. Always state temperature at which the determinations were made. (a) ABBE'S REFRACTOMETER. A later and much improved model of the Abbe instrument, in which arrangements are made for controlling the temperature, the weakness of the older form,b is described in Benedikt. ° (b) ZEISS BUTYRO-REFRACTOMETER. (1 Place the instrument (fig. 1) upon a table where diffuse daylight or any form of artificial light can be readily admitted for illumination. Supply through nozzle D a FIG. 1.— Zeiss's butyro-refractometer. stream of water of constant temperature. Then open the prism casing by giving to the pin F a half turn. The surfaces of the prism must now be cleaned with the greatest care, which is best done by applying soft linen moistened with ether. Now »H. R. Procter, Jour. Soc. Chem., Ind., 1898, 17, 1021-1026, has shown that the Lorenz formula , and gives table for calculation. 1 tfi vcs much more satisfactory results than >>For a description of the older form of the Abbe instrument, see U. S. Dept. Agr., Div. Chem., Bui. •HI, revised, p. 49. An;il. di-r. Fette ii. \VnHi. .:',(] ed.. p. 105. •'Wiley, I'rin. mid I'rne. Airr. Anal., v« >].:{, pp. :t:>(.i-:{ll. Also description by manufacturer. 24 PROVISIONAL METHODS FOB ANALYSIS OF FOODS. melt the sample of fat and pour the clear fat through a filter, allowing the first two or three drops to fall on the surface of the prism contained in casing B (oils must be filtered if turbid) . For this purpose the apparatus should be. raised with the left hand, so as to place the prism surface in a horizontal position. Then press B against A and bring F back into its original position by turning it in the opposite direction. Adjust the mirror until it gives the sharpest reading. If the reading be not distinct after running water of a constant temperature through the instrument for some time, the fat is not evenly distributed on the surfaces of the prism and the process must be repeated. The instrument should be carefully adjusted by means of the standard fluid which is supplied. As the index of refraction is greatly affected by tempera- ture, care must be used to keep it constant. The following table can be used to convert the degrees of the instrument into refractive indices: Butyro-r efractometer readings and indices of refraction. a Reading. Index of refraction. Reading. Index of refraction. Reading. Index of refraction. Reading. Index of refraction. 40.0 .4524 50.0 1,4593 60.0 1,4659 70.0 1, 4723 40.5 ,4527 50.5 ,4596 60.5 1,4662 70.5 1, 4726 41.0 ,4531 51.0 ,4600 61.0 1,4665 71.0 1, 4729 41.5 ,4534 51.5 ,4603 61.5 1, 4668 71.5 1, 4732 42.0 ,4538 52.0 ,4607 62.0 1,4672 72.0 1,4735 42.5 ,4541 52.5 ,4610 62.5 1,4675 72.5 1,4738 43.0 ,4545 53.0 ,4613 63.0 ,4678 73.0 1, 4741 43.5 ,4548 53.5 ,4616 63.5 ,4681 73.5 1,4744 44.0 ,4552 54.0 ,4619 64.0 ,4685 74.0 1, 4747 44.5 ,4555 54.5 ,4623 64.5 ,4688 74.5 1,4750 45.0 ,4558 55.0 ,4626 65.0 ,4691 75.0 1,4753 45.5 ,4562 55.5 ,4629 65.5 ,4694 75.5 1, 4756 46.0 ,4565 56.0 ,4633 66.0 ,4697 76.0 1, 4759 46.5 ,4569 56.5 1,4636 66.5 ,4700 76.5 1, 4762 47.0 ,4572 57.0 1, 4639 67.0 ,4704 77.0 1,4765 47.5 ,4576 57.5 1,4642 67.5 ,4707 77.5 1,4468 48.0 ,4579 58.0 1,4646 68.0 ,4710 78.0 1, 4771 48.5 ,4583 58.5 1,4649 68.5 1,4713 78.5 1, 4774 49.0 ,4586 59.0 1, 4652 69.0 1,4717 79.0 1, 4777 49.5 ,4590 59.5 1,4656 69.5 1,4720 79.5 1,4780 b Winton, Conn. Expt. Sta., Rept., 1900, pt. 2, p. 143. 4. — DETERMINATION OF IODIN ABSORPTION, HUBL'S METHOD.* (a) PREPARATION OF REAGENTS. lodin solution. — Dissolve 25 grams of pure iodin in 500 cc of 95 per cent alcohol. Dissolve 30 grams of mercuric chlorid in 500 cc of 95 per cent alcohol. The latter solution, if necessary, is filtered, and/then the two solutions are mixed. The mixed solution should be allowed to stand twelve hours before using. Decinormal sodium thiosulfate solution. — Dissolve 24.8 grams of chemically pure sodium thiosulfate freshly pulverized as finely as possible and dried between filter or blotting paper, and dilute with water to 1 liter at the temperature at which the titrations are to be made. Starch paste. — One gram of starch is boiled in 200 cc of distilled water for ten min- utes and cooled to room temperature. Solution of potassium iodid. — One hundred and fifty grams of potassium iodid are dissolved in water and made up to 1 liter. Solution of potassium bichromate. — Dissolve 3.874 grams of chemically pure potas- sium bichromate in distilled water and make the volume up to 1 liter at the tempera- ture at which the titrations are to be made. The bichromate solution should be checked against pure iron. •U. S. Dept. of Agr., Div. of Chem., Bui. 4(1 revised, p. EDIBLE OILS AND FATS. 25 (b) DETERMINATION. (1) Standardizing the sodium thiosulfate solution. Place 20 cc of the potassium bichromate solution, to which has been added 10 cc of the solution of potassium iodid, in a glass-stoppered flask. Add to this 5 cc of strong hydrochloric acid. Allow the solution of sodium thiosulfate to flow slowly into the flask until the yellow color of the liquid has almost disappeared. Add a few drops of the starch paste, and with constant shaking continue to add the sodium thiosulfate solution until the blue color just disappears. The number of cubic centimeters of thiosulfate solution used multiplied by 5 is equivalent to 1 gram of iodin. Example: Twenty cubic centimeters of bichromate solution required 16.2 cc sodium thiosulfate; then 16. 2X5=81 = number cubic centimeters of thiosulfate solution equivalent to 1 gram of iodin. Then 1 cc thiosulfate solution =0.0127 gram of iodin. Theory for decinormal solution of sodium thiosulfate 1 cc =0.0127 gram of iodin. (2) Weighing the sample. a Weigh about 1 gram of fat or 0.500 gram of oilb on a small watch crystal0 or by other suitable means. The fat is first melted, mixed thoroughly, poured onto the crystal and allowed to cool. Introduce the watch crystal into a wide-mouth 16-ounce bottle with ground-glass stopper. ( 3 ) A bsorption of iodin. The fat or oil in the bottle is dissolved in 10 cc of chloroform. After complete solution has taken place, 30 cc of the iodin solution are added in the case of fats, or from 40 to 50 ccd in the case of oils. Place the bottle in a dark place and allow to stand, with occasional shaking, for three hours. e This time must be closely adhered to in order to get good results. The excess of iodin should be at least as much as is absorbed. (4) Titration of the unabsorbed iodin. Add 20 cc of the potassium iodid solution, and then 100 cc of distilled water to the contents of the bottle. Wash any iodin which may be noticed upon the stopper back into the bottle with the potassium iodid solution. Titrate the excess of iodin with the sodium thiosulfate solution, which is added gradually, with constant shak- ing, until the yellow color of the solution has almost disappeared. Add a few drops of starch paste, and continue the titration until the blue color has entirely disap- peared. Toward the end of the reaction stopper the bottle and shake violently, so that any iodin remaining in solution in the chloroform may be taken up by the potassium iodid solution. The excess of sodium thiosulfate solution should be sufficient to prevent a reappearance of any blue color in the flask for five minutes. (5) Setting the value of iodin solution by thiosulfate solution. At the time of adding the iodin solution to the fat, two bottles of the same size as those used for the determination should be employed for conducting the operation described above, but without the presence of any fat. In every other respect the "The writer has found it unsatisfactory to weigh so small amounts of fat in flask as directed in the A. O. A. C. methods. »> With drying oils which have a very high absorbent power, 0.100 to 0.200 gram should be taken. «See appendix, p. 150. •'F. Ulzer, Jour. Soc. Chem. Ind., 1898, 17, 276, says iodiu should be in excess about twice the amount that is absorbed. The solution loses strength with age, but can be used so long as 35 cc of decinor- mal thiosulfate neutralize 25 cc iodin solution. •The time allowed does not give the complete iodin absorption power of an oil or fat and can not be compared with determinations where six to twelve hours have been used. It tfivt-s very satisfac- tory comparative results, but the time factor nuM )„. very closely adhered to. 26 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. performance of the blank experiments should be just as described. These blank experiments must be made each time the iodin solution is used. Example blank determinations: Forty cc iodin solution required 62.05 cc of sodium thiosulphate solution. Forty cc iodin solution required 62.15 cc of sodium thiosul- phate solution. Mean, 62.1 cc. Per cent of iodin absorbed: Weight of fat taken grams. . 1. 0479 Quantity of iodin solution used cubic centimeters. . 40. 0 Thiosulfate equivalent to iodin used do 62. 1 Thiosulfate equivalent to remaining iodin do 30. 2 Thiosulfate equivalent to iodin absorbed do 31. 9 Per cent of iodin absorbed, 31. 9x0.0124x100-=-!. 0479=37.75. 5. — DETERMINATION OF SAPONIFICATION NUMBER AND SOLUBLE AND INSOLUBLE ACIDS. a The saponification number, and soluble and insoluble acids, are determined in one sample by the following method: (a) PREPARATION OF REAGENTS." Standard sodium hydroxid solution. — A decinormal solution of sodium hydroxid is used. Each cubic centimeter contains 0.0040 gram of sodium hydroxid and neu- tralizes 0.0088 gram of butyric acid (C4H8O2). Alcoholic potash solution. — Dissolve 40 grams of good potassium hydroxid in 1 liter of 95 per cent redistilled alcohol.0 The solution must be clear and the potassium hydroxid free from carbonates. Standard add solution. — Prepare accurately a half normal solution of hydrochloric acid. Indicator. — Dissolve 1 gram of phenol phthalein in 100 cc of 95 per cent alcohol. (b) WEIGHING OF SAMPLE. The saponification is carried on in a wide-mouth Erlenmeyer flask holding from 250 to 300 cc. These are cleaned by thoroughly washing with water, alcohol, and ether, wiped perfectly dry on the outside, and heated for one hour at the tempera- ture of boiling water. The flasks are then placed on a tray, covered with a silk handkerchief, and allowed to cool. They must not be wriped with a silk handkerchief within fifteen or twenty minutes of the time they are weighed. About 5 grams of the melted fat, which has been filtered, is run in by m ^ans of a pipette, and after cooling the flask and contents are again weighed. d (c) KOETSTORFER OR SAPONIFICATION NUMBER. e Measure 50 cc of the alcoholic potash solution into the flask by means of a burette or pipette, which is allowed to drain a definite time. Connect the flask with a reflux f condenser and boil for thirty minutes, when the fat is completely saponified. Cool the flask and titrate with half-normal hydrochloric acid, using phenolphthalein as indicator. The Koetstorfer number (milligrams of potassium hydroxid required to saponify 1 gram of fat) is obtained by subtracting the number of cubic centi- meters of hydrochloric acid used to neutralize the excess of alkali after saponification »U. S. Dept. of Agr., Div. of Chem., Bui. 46 revised, p. 47. b See appendix, p. 150. cThe alcohol should be redistilled from potassium hydroxid on which it has been standing for some time, or with which it has been boiled for some time, using a reflux condenser. dSee appendix, p. 150. • Chiefly of value in oil work in the detection of rape-oil, resin, and paraffin products. 'Almost any sort of a reflux condenser will do. A small funnel placed in the mouth of the flask is perfectly satisfactory and very convenient. EDIBLE OILS AND FATS. 27 from number of cubic centimeters necessary to neutralize the 50 cc of alkali added, multiplying the result by 28.06 (mg. potassium hydroxid per cubic centimeter) and dividing by the number of grams of fat used. To calculate the saponification equivalent a divide 56,100 by the saponification number, the saponification equivalent being the number of grams of fat saponified by one equivalent of potassium hydroxid, or 56.1 grams. There is no advantage in stating it in this way, and for sake of uniformity, the Koetstorfer number being more generally used, it would seem advisable to adopt it. (d) SOLUBLE ACIDS. Place the flask on a water bath and evaporate the alcohol. Add such an amount of half-normal hydrochloric acid that its volume plus the amount used in titrating for the saponiiication number will be 1 cubic centimeter in excess of the amount required to neutralize the 50 cc of alcoholic potash added. Connect the flask with a condensing tube 3 feet long made of small glass tubing and place it on the steam bath until the separated fatty acids form a clear stratum on the upper surface of the liquid. Fill the flask to the neck with hot water and cool it in ice water until the cake of fatty acids is thoroughly hardened. Pour the liquid contents of the flask through a dry weighed filter into a liter flask, taking care not to break the cake. Fill the flask again with hot water, set on steam bath until the fatty acids collect at the surface, cool by immersing in ice water, and filter the liquid again into the liter flask. Repeat this treatment with hot water, followed by cooling and filtration of the wash water three times, collecting the washings in the liter flask, and titrate with deci-normal alkali, using phenolphthalein as indicator. The number of cubic centimeters of deci-normal alkali used in this titration dimin- ished by 5 (corresponding to the excess of 1 cc of half-normal acid) and multiplied by 0.0088 gives the weight of butyric acid in the amount of fat saponified; dividing this by the weight of fat taken gives the percentage of soluble acids. (e) INSOLUBLE ACIDS OR HEHNER NUMBER. Allow the flask containing the cake of insoluble acids and the filter paper through which the soluble acids have been filtered to drain and dry for twelve hours in the air. Transfer the filter paper to the flask and dry the flask and contents for three hours in a water- jacketed oven, cool, and weigh. Then dry for another two hours, cool, and weigh. If there be any considerable decrease in weight, repeat the drying. The weight obtained less the weight of the filter paper gives weight of insoluble acids, from which the percentage can be easily calculated. 6. — DETERMINATION OF FREE FATTY ACIDS. b Weigh 20 grams of fat or oil into a flask, add 50 cc of 95 per cent alcohol which has been neutralized with weak caustic soda, using phenolphthalein as indicator, ui id heat to boiling point. Agitate the flask thoroughly in order to dissolve the free fatty acids as completely as possible. Titrate with deci-normal alkali, agitating thoroughly until the pink color persists after vigorous shaking. Express results either as percentage of oleic acid, as acid degree (cubic centimeters of normal alkali ivi|iiirvd to neutralize the free acids in 100 grams of oil or fat), or as acid value (milligrams of potassium hydroxid required to saturate the free acids in 1 gram of fat or oil). 1 cc deci-normal alkali =0.0282 grams oleic acid. 7. — DETERMINATION OF VOLATILE ACIDS OR REfcHERT-MEissL NCMHKK. Sec methods for dairy products p. 38. 'Allen, Com. Org. Anal., 3d ed., vol. 42, pt. 1. pp. '• Allen, Coin. Ortf. Anal., M «•«!.. vol. '2, p. 10V 28 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. 8. — FOR ESTIMATION OF LIQUID AND SOLID FATTY ACIDS, MUTER' s METHOD a MODI- FIED BY LANE.b Weigh 5 grams of oil or fat into an Erlenineyer flask, saponify, precipitate with lead acetate, and extract with ether, as directed under determination of arachidic acid. Filter the ether solution of soluble lead soap into a Muter tube or separatory fun- nel and decompose the soap by shaking with 40 cc of a 1 : 5 solution of hydrochloric acid. The soap is completely decomposed when the ether becomes clear and colorless. The lead chlorid is drawn off from the ether solution and the ether washed free from acid. An aliquot of this ether solution is evaporated free from ether in an atmosphere of carbon dioxid in order to prevent the oxidation of the oleic acid, and weighed to determine the per cent of liquid acids; .2 to .3 gram of this is weighed and the iodin number determined in the ordinary way. As it is very difficult to dry the oleic acid without very serious oxidation, it is just as satisfactory to determine the weight of insoluble acids by the following method: Wash the insoluble soap left on the filter into a flask, decompose with hydro- chloric acid, and heat until the fatty acids are melted. Fill the flask with hot water, cool, pour off the water, and wash again the solidified fatty acids. Dissolve them in hot 95 per cent alcohol, transfer to weighed dish, remove the alcohol by evaporation, dry, weigh, and calculate the percentage of solid fatty acids. 9. — DETERMINATION OF ACETYL VALUE.C Benedikt proposed to determine the hydroxy acids and" alcohols by the use of acetic anhydrid (C2H3O)20 as illustrated in the following reaction :d C17H32(OH)COOH-f(C2H30)20=C17H32(OC2H30)COOH+HC2H302 He proposed to work on the fatty acids, but the process was modified by Lewko- witsch e who works on the oils or fats directly, which gives more exactly the true content of hydroxy acids. f The procedure is as follows: Boil the oil or fat with an equal volume of acetic anhydrid (C2H3O)2O for two hours and pour the mixture into a large beaker containing 500 cc of water and boil for half an hour. To prevent bumping, a slow current of carbonic acid is passed into the liquid through a finely drawn out tube reaching nearly to the bottom. Allow the mixture to separate into two layers, siphon off the water, and boil the oily layer with fresh water until it is no longer acid to litmus paper. The acetylated fat is then separated from the water and dried and filtered in a drying oven. Weigh from 2 to 4 grams of the acetylated fats into a flask and saponify with alcoholic potash as in the determination of saponification equavalent. If the distil- lation process is to be adopted it is not necessary to work with a standardized alco- holic potash solution. In case the filtration method is used, which will be found much shorter, it is necessary that the alcoholic potash should be measured exactly. In either case evaporate the alcohol after saponification and dissolve the soap in water. Now two procedures are possible — either distillation or filtration. (a) DISTILLATION PROCESS. Acidify with dilute sulphuric acid (1-10) and distill the liquid as in the Reichert test. As several hundred cubic centimeters must be distilled, either a current of »J. Muter and L. L. De Koningh, Analyst, 1889, 14, 61. '• X. J. Lane, Jour. Am. Chem. Soc., 1893, 15, 110. c Lewkowitsch, Jour. Soc. Chem. Ind., 1897, 16, 503-506; Benedikt, Analyse der Fette u. Wach, 3d ed., p. 146; Allen, Com. Org. Anal., 3d ed., 2, pt. 1, pp. 66-67. (1 Benedikt and Lewkowitsch, Oils, Fats, and Waxes, p. 127. • .lour. S.>c. ('In-ill. Ind., 1897, 16, 503. f J. Lewkowitsch, Jour. Soc. Chem. Ind., 1890, 9, 846. EDIBLE OILS AND FATS. 29 steam in run through or portions of water are added from time to time. From 500 to 700 cc of distillate will be found to be sufficient. Filter the distillates to remove any insoluble acids carried over by the steam, and titrate the filtrate with deci-normal potassium hydroxid, using phenolphthalein as indicator. Multiply the number of cubic centimeters of alkali employed by 5.61 and divide by the weight of substance taken. This gives the acetyl value. (b) FILTRATION 1'KOCKSS. Add to the soap solution a quantity of standard sulphuric acid exactly correspond- ing to the amount of alcoholic potash added, warm gently, and the free fatty acids will collect on top. Filter off the liberated fatty acids, wash with boiling water until the washings are no longer acid, and titrate the filtrate with deci-normal potassium hydroxid, using phenolphthalein as indicator. Calculate the acetyl value as before. 10. — DETERMINATION OP PHYTOSTEROL AND CHOLESTEROL. a Boil 50 grams of fat or oil in a flask with reflux condenser with 75 cc of 95 per cent alcohol for five minutes and separate alcoholic solution. Repeat with another portion of alcohol and separate. Mix the alcoholic solution with 15 cc of 30 per cent sodium hydroxid and boil in a flask with a condensation tube until one-fourth of the alcohol is evaporated. Evaporate nearly to dry ness in porcelain dish and shake the residue with ether. The ethereal solution is evaporated to dryness, taken up with a little ether, filtered, again evaporated, dissolved in hot 95 per cent alco- hol and allowed to crystallize. Cholesterol can easily be distinguished from phytosterol by the form and group- ing of the crystals; also by the melting point, which is 14(>° C.,1' while that <>f phy- tosterol is from 130° to 137.5° C.c Phytosterol is found in most vegetable oils, with the notable exception of olive and palm oil. The crystals as separated from hot alcohol appear in tufts of needles. Cholesterol is characteristic of animal fats. It crystalli/es in thin rhombic tables. 11. — DETERMINATION OF THE UNSAPONIFIABLE Ki>nx K.' Saponify 5 grams" of oil or fat with alcoholic potassium hydroxid and remove the alcohol by evaporation. Wash into separatory funnel with from 70 to 100 cc of water and extract with from 50 to 60 cc of ether. In case the two liquids do not separate, a few cubic centimeters of alcohol may be added. Separate the water solution and wash the ether with water containing a few drops of sodium hydroxid. Again extract the soap solution and washings with ether and evaporate the combined extracts to dryness. In most cases it is advisable to add a little alcoholic potassium hydroxid to the residue and heat in order to saponify any traces of fats left unsaponified and extract again with ether. Transfer to a weighed dish and dry as quickly as possible in a water oven. Many of the hydrocarbon oils are volatile at 100° C., so that the drying should not In- carried any further than necessary. With resin oil, paraffin wax, and the denser mineral oils there is little danger of loss at 100°. On account of the solubility of soap in ether and petroleum ether it is well to wash the residue with warm water containing a little phenolphthalein. If it shows alka- line reaction there is soap present. •Forster and Reichelmann Analyst, 1897, 22, 131; E. Salkowski, Ztsch. anal. Chem., 1887. •-'»;. 687; K. You Kiimn.T, Ztsch. angew. Chem., 1898, 18, 555-566; Jour. Soc. Chem. Iiid., 1898, 17. 771. H. Kn-is mid O. Wolf, Jour. Soc. Chem. Ind., 1898, 17, 1075. '• K. Siilkmvski. Xtschr. anal. Chem., 1887, •-'«. 587. I'.r.in.T, y.tsHir. rntt-r. (1. Nahru. Gciiuss. iv.w, 1, 81. •Allen, com. OI-K. Anal., 3d Ed., Vol. 2, pp. land 118, 30 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. 12. — DETERMINATION OF MELTING POINTS OF FATS* — WILEY'S METHOD." (a) PREPARATION OF REAGENTS. Have a piece of ice floating in distilled water that has been recently boiled. Pre- pare a mixture of alcohol and water of the same specific gravity as the fat to be examined. This is done by boiling distilled water and 95 per cent alcohol for ten minutes to remove the gases which they may hold in solution. While still hot, the water is poured into the test tube described below (2) until it is nearly half full. The test tube is nearly filled with the hot alcohol, which is carefully poured down the side of the inclined tube to avoid too much mixing. If the alcohol is not added until the water has cooled, the mix- ture will contain so many air bubbles as to be unfit for use. These bubbles will gather on the disk of fat as the temperature rises and finally force it to the top. (b) APPARATUS. The apparatus for determin- ing the melting point consists of an accurate thermometer read- ing easily tenths of a degree; a cathetometer for reading the thermometer (but this may be done with an eyeglass if held steadily and properly adjusted) ; an ordinary thermometer; a tall beaker 35 cm high and 10 cm in diameter; a test tube 30 cm long and 3.5 cm in diameter; a stand for supporting the apparatus; some method of stirring the water in the beaker (for example, a blowing bulb of rubber, and a bent glass tube extending to near the bottom of the beaker ) . ( See fig. 2.) (c) DETERMINATION. w. SCKOLL a«i FIG. 2. — Apparatus for the determination of the melting point. The disks of fat are prepared as follows: The melted and fil- tered fat is allowed to fall from a dropping tube from a height of from 15 to 20 cm on a smooth piece of ice floating in distilled water that has been recently boiled. The disks thus formed are from 1 to 1.5 cm in diameter, and weigh about 200 mg. By pressing the ice under the water the disks are made to float on the surface, whence they are easily removed with a steel spatula, which should be cooled in the ice water before using. The disks must be allowed to stand for two or three hours in order to obtain the normal melting point. The test tube containing the alcohol and water is placed in a tall beaker contain- aSee Appendix, p. 151. 11 F. S. Dept. of Agr., Div. of Chem., Bui. 46 revised, p. 52. EDIBLE OILS AND FATS. 31 ing water and ice, until cold. The disk of fat is then dropped into the tube from the spatula, and at once sinks until it reaches a part of the tube where the density of the alcohol water is exactly equivalent to its own. Here it remains at rest and free from the action of any force save that inherent in its own molecules. The delicate thermometer is placed in the test tube and lowered until the bulb is just above the disk. In order to secure an even temperature in all parts of the alcohol mixture in the vicinity of the disk, the thermometer is moved from time to time in a circularly pendulous manner. The disk having been placed in position, the water in the beaker is slowly heated and kept constantly stirred by means of the blowing apparatus already described. When the temperature of the alcohol-water mixture rises to about 6° C. below the melting point, the disk of fat begins to shrivel and gradually rolls up into an irreg- ular mass. The thermometer is now lowered until the fat particle is even with the center of the bulb. The bulb of the thermometer should be small, so as to indicate only the temperature of the mixture near the fat. A gentle rotary movement should be given to the thermometer bulb. The rise of temperature should be so regulated that the last 2° C. of the increment require about ten minutes. The mass of fat gradually approaches the form of a sphere, and, when it is sensibly so, the reading of the ther- mometer is to be made. As soon as the temperature is taken the tube is removed from the bath and placed again in the cooler. A second tube, containing alcohol and water, is at once placed in the bath. The test tube (ice water having been used as a cooler) is of low enough temperature to cool the bath sufficiently. After the first determination, which should be only a trial, the temperature of the bath should be so regulated as to reach a maximum of about 1.5° above the melting point of the fat under examination. The edge of the disk should not be allowed to touch the sides of the tube. This accident rarely happens, but in case it should take place and the disk adhere to the sides of the tube a new trial should be made. Triplicate determinations should be made, and the second and third results should show a near agreement. Example: Melting point of sample of butter: Degrees. First trial ......................................................... 33. 15 C. Second trial ....................................................... 33. 05 C. Third trial ........................................................ 33.100. 13. — DETERMINATION OF MELTING POINT OF FATTY ACIDS. a Draw up the melted fatty acid into a very thin-walled capillary tube 1 or 2 inches long according to the length of bulb of the thermometer used. Seal one end of the tube and allow the fatty acid to cool on ice for from twelve to fifteen hours. Then attach to the bulb of a delicate thermometer graduated to one-fifth degree, immerse in a beaker of water, and warm up very slowly. The point where the acid becomes transparent is taken as the melting point. 14. — DETERMINATION OF MAIMKM': NIMBKR." The following apparatus has been largely used by the writer and has given very satisfactory results: A beaker, 5 inches by 1£ inches, is placed inside ot another 6 inches by 3 inches, and a wet mixture of asbestos and plaster of paris tightly packed around the inner l>eaker. This, when dried, makes a hard, solid packing which radiates heat very slowly. •r. S. I>»-pt. of AKF.. Div. of Clicin., Bui. i:?. pi. I. p. I Lv Bi-m-ilikt nn, 17. 721. »' Kenard, Comp. Kend., ls71, IX. i:',:;o. Benedikt and Lewkovvitseh, ( tils. Fats, and Waxes, p. 8(5. i Process u-ed by N. .1. Lane in his modification of Miner's method, .lour. Am. Chem. Soc.. l.x'.i:1,. K», 110. HUMS No. <;:>— 02 3 34 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. be dissolved, while in lards, where there is so much stearin, part will be left undis- solved. Cool the ether solution of soap down to from 15° to 17° C., and allow to stand until all the insoluble soaps have, crystallized out. It should stand about twelve hours. Now, filter and wash the precipitate with* ether. Save the filtrate for the deter- mination of the iodin number of the liquid fatty acids by the Muter method. * The soaps on the filter are washed back into the flask by means of a stream of hot water acidified with hydrochloric acid. Add an excess -of dilute hydrochloric acid, fill up the flask with hot water, allow the free fatty acids to harden and separate from the precipitated lead chlorid, wash, drain, and dissolve the fatty acids in 25 cc of boiling 90 per cent (by volume) alcohol. The crystals of arachidic acid separate out as the liquid cools. From 5 to 10 per cent of peanut oil can be detected by this method, as it effects a complete separation of the soluble acids from the insoluble, which interfere with the crystallization of the arai'hidic acid. Filter, wash the precipitate twice with 10 cc of 90 per cent (by volume) alcohol, and then with alcohol of 70 per cent (by volume). Dissolve off the filter with boiling absolute alcohol, evaporate to dryness in a weighed dish, dry and weigh. Add to this weight 0.0025 gram for each 10 cc of 90 per cent alcohol used in the crystallization and washing if done at 15° C., if done at 20°, 0.0045 gram for each 10 cc. The melting point of arachidic acid obtained in this way is between 71° and 72° C. Twenty times the weight of arachidic acid will give the approximate amount of peanut oil present. Another method a which gives as satisfactory an approximation of the amount of peanut oil present is to allow the arachidic b acid to crystallize in a 100 cc graduated cylinder and measuring the volume of the precipitate. This volume will have to be determined for the working temperature and the length of the time by use of known mixtures of peanut oil. Cotton-seed and lard oil give slight precipitates when treated by this method. Arachidic acid has a characteristic structure and can be detected by the microscope. No examination of olive oil is complete without making the test for peanut oil, which is probably a common adulterant, especially in French and Italian oils. 19. — BAUDOUIN TEST FOR SESAME OIL. Dissolve 0.1 gram of finely powdered sugar in 10 cc of hydrochloric acid (sp. gr. 1.20) , add 20 cc of the oil to be tested, shake thoroughly for a minute and allow to stand. The aqueous solution separates almost at once. In the presence of even a very small admixture of sesame oil, this is colored crimson. Some olive oils give a slight pink coloration with this reagent, but they are not hard to distinguish if comparative tests with sesame oil are made. 20. — VILLIVECCHIA c TEST FOR SESAME OIL. Mix 2 grams of furfurol with 100 cc alcohol (95 per cent), and take 0.1 cc of this solution, 10 cc hydrochloric acic (sp. gr. 1.20), and 10 cc of oil and mix thoroughly by shaking in a test tube and the same color is developed as when the sugar is used. Villivecchia attributed the Baudouin test to the formation of furfurol from the action of levulose and hydrochloric acid, and so substituted furfurol for sucrose. As furfurol and hydrochloric acid give a violet tint with hydrochloric acid, it is necessary to use the very dilute solution given in the method. •Suggested by W. D. Bigelow. b As the solubility of arachidic acid in 90 per cent alcohol increases very rapidly with the tempera- ture, care must be taken to keep the temperature of crystallization down to between 15° and 20° C., and to obtain satisfactory results the temperature must be same as used in the standards. = Villivecchia and Pabris, Journ. Soc. Chem. Ind., 1893, 12, 97 and 1894, 13, 69. Benedikt and Lew- kowitsch. Oils, Fats, and Waxes, p. 318. DAIRY PRODUCTS MILK AND CREAM. 35 21. — TOCHER" TEST FOR SESAME OIL. Dissolve 1 gram pyrogallol in 15 cc of concentrated hydrochloric acid. Mix this solution with 15 oc of oil in a separatory funnel and allow to stand for a minute. Draw off the aqueous layer and boil for five minutes. In the presence of sesame oil it becomes colored red by transmitted light and blue by reflected light. 22. — MICROSCOPICAL EXAMINATION. b Dissolve in a test tube from 2 to 5 grams of oil or fat in about 10 cc of ether, plug the test tube lightly with cotton and allow to stand 15 or more hours in a moderately cool place. The most characteristic crystals are obtained when the crystallization proceeds slowly and at temperature of from 22° to 24° C. The first crop of crystals may be examined and the mother liquor separated and set aside for further crystallization. In order to get rid of the oleins, Gladding0 has suggested the following: Dissolve in an Erlenmeyer flask 5 grams of melted fat in 10 cc of absolute alcohol and 5 cc of ether, stopper with cotton and place in ice water for about one-half hour, until the more crystallizable portions of the fat have separated. The crystalline part is separated by filtration through a filter paper moistened with alcohol, and washed with the alcohol-ether mixture. After drying in the air for some time the crystals are dissolved from the paper by means of ether and then treated in the same way as described in the first method. When the crystals are ready to examine a drop is removed with a pipette, placed on a slide, a drop of cotton oil or olive oil added, and a cover slip pressed gently down. III.— DAIRY PRODUCTS. By J. A. LECLERC, State Experiment Station, Geneva, N. Y. (A) MILK AND CHE AM. 1. — GENERAL DISCUSSION. There are three kinds of adulteration generally practiced with milk. First, addition of water, which is the simplest and the most common practice. Second, removal of fat or the removal of fat and addition of water. This double adultera- tion is used in order not to disturb the specific gravity. Third, the addition of preservatives, most commonly formaldehyde, boric acid, or borax. The determinations ordinarily made in the examination of milk and cream are specific gravity, fat, total solids, solids not fat, and the detection of preservatives and coloring matter. The specific gravity alone is of little value in judging the purity of milk, owing to the fact that the increase of specific gravity produced by the removal of cream may be reduced by the addition of water. One of the most important con- siderations is the relation of the solids not fat to the fat. In milk it has been found that this ratio does not vary wridely from 9:4. 2. — DETERMINATION OF TOTAL SOLIDS. (1 Heat at 100° C. to constant weight about 3 grams of milk in a tared platinum, aluminum, or tin dish' of 5 cm diameter, with or without the addition of 15 to 30 grains of sand. Cool and weigh. •Phnrr.i. .Tourn. mid Trans., 1891, 639. Chem. Zeit,, Rep., 1891, 5, 15-33. Bcncdikt and Lewko- \vitsrh, Oils, Fats, mid Wnx.-s. p. :tl'.». Wintmi. , :;n;. Win ton, Report Conn. Expt. Sta., 1900, pt. 2, p. M.\ "Jour. Am. ('hem. Soe., IS(.M>, IS, l,x«i. 11 T. S. I)ept. of Atfr., Div. of ('hem.. Hill. Hi revised, p. 54. Appendix, p. ! .1. 36 PROVISIONAL METHODS FOE ANALYSIS OF FOODS. 3. — DETERMINATION OF FAT. (a) OFFICIAL METHOD.* Dry about 5 grains of the sample on ignited asbestos in a Hofmeister schalchen or in a perforated metal cylinder (described by Babcock) and extract with ether in a continuous extraction apparatus. (b) BABCOCK'S METHOD. b This method is commonly used where a large number of samples is to be examined. Owing to the general use of this method and its wide publication it is not deemed advisable to introduce its description here. (c) GERBER'S METHOD. Where only occasional samples are to be examined Gerber's acid butyrometer is found to give results comparable with those of the Babcock apparatus and is much more convenient. Directions accompany the apparatus. 4. — DETERMINATION OF SOLIDS .NOT FAT. Deduct the percentage of fat from the percentage of total solids. 5. — DETECTION OF GELATIN. c "An acid solution of mercuric nitrate is prepared by dissolving mercury in twice its weight of nitric acid of 1.42 specific gravity, and diluting this solution to 25 times its bulk by the addition of water. Ten cubic centimeters of the milk or cream to be examined are mixed with an equal volume of the acid mercuric nitrate solution, the mixture is shaken, and then 20 cc of water are added. The liquid is again shaken, allowed to stand five minutes, and filtered. In the presence of much gelatin the filtrate will be opalescent and can not be obtained quite clear. To a por- tion of the filtrate contained in a test tube an equal volume of a saturated aqueous solution of picric acid is added. A yellow precipitate will be produced in presence of any considerable amount of gelatin, while smaller amounts will be indicated by the cloudiness produced by the picric acid solution. In the absence of gelatin the filtrate obtained will be perfectly clear, and will be unaffected by adding picric acid." 6. — DETECTION OF FORMALDEHYDE.*1 To the milk to be tested add strong commercial sulphuric acid without mixing, and at the junction of the two liquids a violet or blue color will appear if the milk contains one or more parts per 10,000 of formaldehyde. This color is supposed to be given only when there is a trace of ferric chlorid or other oxidizing agent present. Other methods of detecting formaldehyde are described on pages 79 and 107. 7. — DETECTION OF BORAX AND BORIC ACID. Use methods described on page 110. 8. — DETECTION OF FOREIGN COLORS. (a) LEACH'S METHOD. e Warm about 150 cc of milk in a casserole over the flame and add about 5 cc of. acetic acid, after which slowly continue the heating nearly to the boiling point while » U. S. Dept. of Agr., Div. of Chem., Bui. 46 revised, p. 54. >• Wis. Kxp. Sta. Bui. No. 24, and U. S. Dept. of Agr., Div. of Chem.. Bui. No.. 28, p. 34-42. «Allen, Com. Org. Anal., 2d ed., Vol. IV, pp. 181-182. d See Appendix, ]>. 151. «Jour. Am. Chem. Soc., 1900, 22, 207, DAIRY PRODUCTS — BUTTER. 37 stirring. Gather the curd, when possible, into one mass by the stirring rod, and pour off the whey. If the curd breaks up into small flecks, separate from the whey by straining through a sieve or colander. Press the curd free from adhering liquid, transfer to a small flask, and macerate for several hours (preferably over night) in about 50 cc of ether, the flask being tightly corked and shaken at intervals. (1) Detection of annatto (in the etfier extract). Decant the ether extract into an evaporating dish, place on the water bath, and evaporate off the ether. Make the fatty residue alkaline with sodium hydroxid, and pour upon a very small wet filter while still warm. After the solution has passed through, wash off the fat from the filter with a stream of water and dry the paper. If, after drying, the paper is colored orange, the presence of annatto is indicated, confirmed by applying a drop of stannous chlorid solution, which, in presence of annatto, produces a characteristic pink on the orange-colored paper. (2) Detection of aniline orange (in the curd) . The curd of an uncolored milk should be perfectly white after complete extraction with ether, as would also that of a rnilk colored with annatto. If the extracted fat-free curd is distinctly dyed an orange or yellowish color, aniline orange is indicated. To confirm the presence of this color, treat a lump of the fat-free curd in a test tube with a little strong hydrochloric acid. If the curd immediately turns pink, the presence of aniline orange is assured. (3) Detection of caramel (in the curd). If the fat-free curd is colored a dull brown, caramel is to be suspected. Shake a lump of the curd, as in (b), with strong hydrochloric acid in a test tube and heat gently. The acid solution of the caramel-colored curd will gradually turn a deep blue, as would also the white, fat-free curd of an uncolored milk, while the curd itself does not change color. a (b) LYTHGOE'S TEST FOR ANILINE ORANGE.** Treat about 10 cc of the milk with an equal volume of hydrochloric acid (sp. gr. 1 . 20) in a porcelain casserole, and give the dish a slight rotary motion. Ir aniline orange is present in appreciable amount a pink color will at once be imparted to the curd particles as they separate out. (B) BUTTER. 1. — GENERAL DISCUSSION. The most common adulteration of butter is the substitution of fat other than butter fat. This is effected either by oleomargarine or by mixtures of oleomargarine and butter. Within the last few years a new product, called process or renovate* 1 butter, has been sold extensively as butter. The process of its manufacture is, briefly, as follows: Poor and rancid butter is melted, the curd and brine are allowed to settle, the froth and scum skimmed off, after which the clear fat is drawn off and completely aerated so as to remove any unpleasant odors. Next, pure skimmed or whole milk is added and the mixture is thoroughly stirred so as to form a complete emulsion, ami is •It should be noted that it is only when this blue coloration of the acid occurs in connection with a hroii'n-c(if»r<'(t curd, which itself does not change color, that caramel is to be suspected, a« distin- guished from the pink coloration produced at once under similar conditions by aniline on in, ire. It is to be regretted that there are no such delinile confirmatory tesls for caramel as there are for annatto and aniline orange. See I'.Mli An. Rep. Mass. Stute Board of Health (l.ssTi. p. l,s;i. '•Jour. Am. Chem. Soc., I'.lOO, •_'•_', 81o. 38 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. finally sprayed into ice-cold water so as to give the product that granular appearance usually found in butter just from the churn. It is then treated and sold as butter. When this product, or its mixture with butter, is sold as butter it should be consid- ered an adulteration. In addition to the special methods given below for the detec- tion of process butter, the general methods described under Edible Fats and Oils must often be employed. Excessive amounts of water or of casein should be regarded as adulterations. Occasionally preservatives other than salt are added to butter, but they are generally the same as those found in milk. 2.— DETERMINATION OF WATER.* Place from 1.5 to 2.5 grams of the sample in a flat-bottomed dish having a surface of at least 20 square centimeters, and dry to constant weight at the temperature of boiling water. The use of clean, dry sand or asbestos with the butter is admissible, and is neces- sary if a dish with round bottom be employed. 3. — DETERMINATION OF FAT. a (a) DIRECT METHOD. Dry the butter on asbestos or sand to determine the water, and extract the fat by anhydrous alcohol-free ether. Evaporate the ether from the extract, heat to constant weight at the temperature of boiling water, and weigh. (b) INDIRECT METHOD. Dissolve the dry butter from the water determination in the same dish with absolute ether or with 76° C. petroleum ether. Then transfer the contents of the dish to a weighed Gooch crucible with the aid of a wash bottle filled with the solvent, and wash until free from fat. Heat the crucible and contents at the temperature of boiling water until the weight is constant, and calculate the weight of fat from the data obtained. 4. — DETERMINATION OF REICHERT-MEISSL NUMBER. Employ the official method of the association. b 5. — DETERMINATION OF SAPONIFICATION VALUE. Proceed as directed on page 26. 6. — THE WATERHOUSE TEST FOR OLEOMARGARINE. c Half fill a 100-cc beaker with sweet milk, heat nearly to boiling, and add 5 to 10 grams of butter or oleomargarine. Stir with a small rod, preferably of wood and about the size of a match, until the fat is melted. Then place the beaker in cold water and stir the. milk until the temperature falls sufficiently for the fat to congeal. At this point the fat, if oleo, can easily be collected into one lump by means of the rod, while if butter it will granulate and can not be so collected. The distinction is very marked. 7. — SPECIAL TESTS FOR PROCESS BUTTER. d (a) FOAM TEST. e Heat 2 or 3 grams of the sample, either in a spoon or dish, over a free flame. True butter will foam abundantly, whereas process butter will bump and sputter, »U. S. Dept. of Agr., Div. of Chem., Bui. 46 revised, p. 43. b U. S. Dept. of Agr., Div. of Chem., Bui. 46 revised, pp. 44-46. c Jour. Am. Chem. Soc., 1901, 23, 200; U. S. Dept. Agr., Farmers' Bui. 131, p. 7. dSee Appendix, p. 152. • Jour. Amer. Chem. Soc., 1900, 22, 150; U. S. Dept. of Agr., Farmers' Bui. No. 131. DAIRY PRODUCTS CHEESE. 39 like hot grease, without foaming. Oleo behaves like process butter, but chemical tests and the Waterhouse test described above will indicate whether the sample is oleo or butter, either genuine or process. (b) APPEARANCE OF MELTED BUTTER. a Melt from 50 to 100 grams of butter or process butter at 50° C. The curd from the butter will settle, leaving above it a clear, supernatant fat. On the other hand the supernatant fat in the case of process butter does not assume that clear appear- ance, but remains more or less turbid. (c) MICROSCOPIC EXAMINATION.11 Place a bit of the butter or process butter on a glass slide, cover it and press into a thin film with cover glass. Examine immediately with a polarizing microscope magnifying from 100 to 140 diameters. When a selenite plate is placed between the slide and the lower nicol a normal butter will give a uniformly blue colored field, showing the absence of fat crystals. On the other hand, process butter gives a blue field, mottled with yellow. 8. — DETECTION OP ANNATO AND SAFFRON IN BUTTER — CORNWALL'S METHOD. c Five grams fat are dissolved in 50 cc of ether in a wide tube and the solution is vigorously shaken with 12 to 15 cc of a very dilute solution of potassium hydroxid, which must still be alkaline after it separates from the ether solution. It is allowed to stand a few hours, when the aqueous layer is drawn off, evapo- rated to dryness, and tested with sulphuric acid, which in the presence of annato gives first a blue or violet blue, changing quickly to green, and finally to brown. Saffron which would be extracted at the same time acts differently when treated with sulphuric acid, not giving the green coloration. The aqueous solutions, if not clear enough to use, must not be filtered, as the filter paper will take up large amounts of the color, but can be shaken up again with fresh portions of ether. Martin'1 uses carbon disulphid as a solvent instead of ether, which is just as satis- factory. Genuine butters treated in this way give only a very slight trace of coloring matter. 9. — DETECTION OF ANILINE COLORS. e Follow methods described under Coloring Matter (p. Ill and following). (C) CHEESE. 1. — GENERAL DISCUSSION. There are two kinds of adulterations practiced with cheese. First, the use of fat other than milk fat, producing a product called filled cheese. Second, the removal of varying amounts of fat, producing skim cheese. The liquefied fats of swine or cattle intimately mixed with skim milk produce filled cheese; therefore the chemical methods for the examination of the fat of filled cheese are the same as are used for the detection of adulterated butter. Skim cheese is made from milk from which part or the whole of the fat has been removed; therefore the determination of fat and nitrogenous compound! will give a good indication as to whether the sample under examination is skim cheese. » Jour. Amer. Chem. Soe., 1900, 22, 327. Uour. AUNT. Cln-m. Sor.. I'.MMI. !>•_». :«7. "Chcin. News, vol. 1X.X7. ."».">, 49; U. S. Dept. of Agr., Div. of Chem., Bui. 13, pt. 1, p. 28. •'Analyst, INS:,. | <>. |,;;; \l>|.rn.lix, p. l.VJ. 40 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. 2. — SELECTION OF SAMPLE. a When the cheese can be cut take a narrow wedge-shaped segment reaching from the outer edge to the center of the cheese. Cut this into strips and pass through a sausage-grinding machine three times. When the cheese can not be cut take the sample with a cheese trier. If only one plug can be obtained take it per- pendicular to the surface of the cheese at a point one-third of the distance from the edge to the center and extending either entirely or only half way through it. When possible draw three plugs — one from the center, one from a point near the outer edge, and one from a point halfway between the other two. For inspection purposes reject the rind; but for investigations requiring the absolute amount of fat in the. cheese include the rind in the sample. It is preferable to grind the plugs in a sausage machine, but when this is not done they are cut very fine and carefully mixed. 3. — SEPARATION OF FAT FOR EXAMINATION^ (a) FIRST METHOD.0 Cut about 300 grams of cheese into fragments the size of a pea. Treat with 700 cc of potassium hydroxid (50 grams per liter) at 20° C. in a large wide-necked flask, and promote the solution of casein by vigorous shaking. In from 5 to 10 minutes the casein will be dissolved and the fat will come to the surface in lumps. Collect the lumps of fat into as large a mass as possible by a gentle shaking to and fro. Pour cold water into the flask until the fat is driven up into the neck and remove it by means of a spoon. Wash the fat thus obtained with as little water as will remove the residue of the lye which it may contain. Experience has shown that the fat is not perceptibly attacked by the lye in this treatment. By this method the fat is practi- cally all separated in a short time and is then easily prepared for chemical analysis by filtering and drying as directed in the official method/ (b) SECOND METHOD. Grind the cheese by passing it through a meat-cutting machine. Transfer it to a large flask and pour warm water upon it, using 1 cc for every gram of cheese. Shake thoroughly and add sulphuric acid (sp. gr. 1.82 to 1.825) slowly and in small quan- tities, shaking after each addition of acid. The total amount of acid used should be the same as the amount of water used. Remove the fat, which separates after stand- ing a few minutes, by means of a separatory funnel, wash it free from acid, filter, and dry. 4. — DETERMINATION OF WATER. e Place from 2 to 5 grains of cheese in a weighed platinum dish containing a small quantity of porous material such as ignited asbestos or sand, to absorb the fat which may run out of the cheese. Heat in a water-jacketed bath for ten hours and weigh; the loss in weight is considered as water. Or, if preferred, place the dish in a desic- cator over concentrated sulphuric acid and dry to constant weight. Renew the acid when the cheese has become nearly dry. 5. — DETERMINATION OF FAT. e Cover the perforations in the bottom of the extraction tube with dry asbestos, and on this place a mixture containing equal parts of anhydrous copper sulphate and » U. S. Dept. of Agr., Div. of Chem., Bui. 46 revised, p. 55. b See also Appendix, p. 152. CU. S. Dept. of Agr., Div. of Chem., Bui. 51. d U. S. Dept. of Agr., Div. of Chem., Bui. 46 revised, p. 44, 3 (a). «U. S. Dept. of Agr., Div. of Chem.. Bui. Id revised, p. 56. INFANT AND INVALID FOODS. 41 pure dry sand to the depth of about 5 cm. packing loosely. Cover the upper surface of this material with a film of asbestos and place on it from 2 to 5 grams of the sam- ple of cheese. Place the tube in a continuous extraction apparatus and treat for five hours with anhydrous ether. Remove the cheese and grind to a fine powder with pure sand in a mortar. Replace the mixed cheese and sand in the extraction tube, wash the mortar free of all matters with ether, add the washings to the tube, and continue the extraction for ten hours. 6. — DETERMINATION OF NITROGENOUS COMPOUNDS. Make a determination of nitrogen by the Kjeldahl or the Gunning method, using about 2 grams of cheese, and multiply the percentage of nitrogen found by 6.25. IT.— CEREAL PRODUCTS. By A. McGiLL, Chemist of Inland Revenue Laboratory, Ottawa, Canada. It has been found impossible to prepare the report on this subject this year. The heading has been inserted here to preserve its proper order. V.— INFANT AND INVALID FOODS. By H. W. WILEY, Chief of Bureau of CJiemistry, United States Department of Agriculture. 1. — GENERAL DISCUSSION. Under this head are included all prepared foods of every description, which are intended especially for the use of infants and invalids. » It is evident that foods for infants should be us nearly as possible similar in charac- ter to the natural food, viz, healthy human milk. All modified milk, of the cow and other animals, intended for infants, would be included in this class. If these milks be evaporated, they would differ from the original sample only in the loss of water, provided the evaporation be carried on in vacuum at low temperature. Many of the foods advertised for the use of infants, however, contain starch and other matters not usually found in healthy human milk. The number of foods advertised for the use of infants is legion. Many of them are "predigested," that is, they have the proteid matter reduced to the form of more or less soluble protein and the starchy matters converted more or less completely into soluble carbohydrates. Under the head of infant and invalid foods should also be considered the various products in which nitrogenous bodies are the most important ingredients. Infant foods may be divided into two classes: First, milk of cows and other ani- mals modified to resemble more or less completely healthy human milk; and, second, the foods in which carbohydrates are the predominating element. In this connection it may be stated that preparations of this nature are ordinarily used with milk, and may be considered in a sense as substitutes for milk sugar. The modification of milk consists as a rule in diminishing the proportion of the protein matter or casein and increasing that of milk sugar and fat. By chemical and other treatment, the ordinary average milk of the cow may thus be modified so as to resemble more or less completely the average healthy human milk. It is planned to examine a large number of infant and invalid foods during the coming year, and for that reason the writer had intended to defer his report until the com- pletion of the work mentioned. So many inquiries have recently been received regarding this subject, however, that ii was thought best to prepare for this bulletin a brief sum i nary of methods to 1 teem ployed with references to a previous publication of the writer's describing them. 42 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. 2. — METHODS OF DETERMINATION. Determinations in this case should consist of: (a) WATER. The water can be determined in the usual manner by evaporating a small quantity of the material in a flat dish, so that the film of solid matter may not be too thick. This is preferably done in vacuo or in an atmosphere of inert gas. See Principles and Practice of Agricultural Analysis, vol. 3, pages 13 and following; also Depart- ment of Agriculture, Division of Chemistry, Bulletin No. 46 revised, pages 27 and 43. (b) ASH. Burn the. dried sample at a low red heat, preferably in a muffle. See Principles and Practice of Agricultural Analysis, vol. 3, pages 36 and following; also Bulletin 46 revised, page 23. (C) FAT. Determine by one of the methods given in Principles and Practice of Agricultural Analysis, vol. 3, pages 480 and following, and Bulletin 46 revised, page 54. (d) SUGARS. The lactose may be determined both by reduction of copper salts and by optical processes. See Principles and Practice of Agricultural Analysis, vol. 3, pages 275 and following; and Bulletin 46 revised, pages 40 and following. (e) ADDED SUCROSE. Use method of Bigelow and McElroy, Principles and Practice of Agricultural Analysis, vol. 3, page 296; or that of Stokes and Bodmer, Analyst, 1885, 10, 62. (f) PROTEIN. Use methods described in Principles and Practice of Agricultural Analysis, vol. 3, pages 504 and following, for total protein and separation of protein matters; also Bul- letin 46 revised, pages 54 and 55. 3. — CONDENSED MILK. Mix the entire contents of the (tan, transfer 250 grams to a liter flask, dissolve in water and make the solution up to the mark. The solution should then be treated for various constituents as under dairy products on aliquot parts of the contents of the flask. 4. — CARBOHYDRATE FOODS. Another class of foods for infants and invalids, as intimated above, is chiefly com- posed of carbohydrate bodies. These foods should be examined microscopically to determine, if possible, the origin and character of the starch. The water and ash should be determined by the usual methods. The quantity of starch unchanged should be determined. See Principles and Practice of Agricultural Analysis, vol. 3, pages 201 and following; and Bulletin 46 revised, page 25. (a) DEXTRIN. This can be determined in the solution of the bodies after the fermentation of other sugars. Dextrin can then be determined by its opticity or by precipitation with alcohol. See Principles and Practice of Agricultural Analysis, vol. 3, pages 287 and following. SACCHARINE PRODUCTS. 43 (b) DEXTROSE. Determine dextrose by the methods given in Principles and Practice of Agricul- tural Analysis, vol. 3, pages 287 and following. (c) INVERT SUGAR. See Principles and Practice of Agricultural Analysis, vol. 3, pages 161, 162, 257 and following. (d) MALTOSE. For separation from dextrin and dextrose, see Principles and Practice of Agricul- tural Analysis, vol. 3, pages 287 and following; for estimation, see pages 165 and fol- lowing. The important point to be determined in these foods is the extent to wrhich the so-called predigestion has been carried, and this is done by ascertaining the condi- tion of the carbohydrate and proteid bodies. Attention should also be given to the nature of any ferments which have been employed in effecting the predigestion, or acids, if such have been used. Further, these foods should be examined for pre- servatives, which are sometimes added when the samples are in a liquid state, or are perishable in character. VI.— SACCHARINE PRODUCTS. By ALBERT E. LEACH, Analyst of State Board of Health, Boston, Mass. 1. — GENERAL DISCUSSION. This class of food products, from their nature and composition, is so closely allied to sugar and starch (methods for which have been already so fully studied by this association) that little remains of a purely distinctive character in their examination. Being, furthermore, composed almost exclusively of carbohydrates, it is doubtful if, as a rule, much attention need be given to the determination of nitrogen or fatty con- stituents, which occur in very minute quantities only, and chiefly in chocolate and flavoring material, or in the eggs and butter that enter incidentally into the manu- facture of confectionery. 2. — PREPARATION OF THE SAMPLE. (a) MOLASSES AND SIRUP. Insure a homogenous mixture by stirring with a rod till any crystallized sugar is evenly distributed throughout the mass. (b) HONEY. Treat the strained honey as in the case of molasses, 2 (a) . In the case of comb honey, cut across the top of the comb, if sealed, and sepa- rate completely from the comb by straining through a 40-mesh sieve. If the honey has become wholly or in part solidified by crystallization, use a gentle heat on a closed water bath to restore it to fluid form. (c) CONFECTIONERY. (1) Products of practically uniform composition throughout. (a) Lozenges and other pulverizable products. — Grind in a mortar or mill to a fine powder. 44 PROVISIONAL METHODS FOE ANALYSIS OF FOODS. (6) Semiplastic, sirupy, or pasty products, — Weigh 50 grams of the sample into a 250 -cc graduated flask, mix thoroughly or dissolve, if soluble, in water and fill to the mark. Be sure that the solution is uniform, or, if insoluble material is present, that it is evenly mixed by shaking before taking aliquot parts for the various determi- nations. (2) Confectionery in layers or sections of different composition. When it is desired to examine the different portions separately they should be separated mechanically with a knife when possible, and treated as directed under (1). (3) Sugar-coated fruit, nuts, etc. In case of a saccharine coating enclosing fruit, nuts, or any less readily soluble material, dissolve or wash off the exterior coating in water, which may, if desired, be evaporated to dry ness for weighing, and proceed as in (1). (4) Brandy drops and similar preparations. In case of a hard exterior coating enclosing a sirup or fluid which it is desired to examine, puncture the outer coating with a knife and pour out the fluid, using a sufficient number of the "drops" to yield enough fluid for examination (see page 49, sec. 14). (5) Candied or sugared fruits. Proceed as directed under Preserves and Canned Fruits, page 75. 3. — DETERMINATION OF TOTAL SOLIDS, (a) MOLASSES, SIRUPS, AND HONEY. (1) By direct determination. Weigh 20 grams into a 100-cc graduated flask, dissolve in water and make up to the mark. Insure a uniform solution by shaking. Measure 10 cc of this solution into a tared platinum dish containing about 5 grams of freshly ignited, finely divided asbestos fiber, and dry to constant weight at 70° in vacuo or in a McGill oven (see footnote on page 76). (2) By calculation from specific gravity. a Weigh 25 grams of the sample into a 100-cc graduated flask, dissolve in Water and make up to the mark. Determine the specific gravity of the diluted solution by means of a pycnometer or Westphal balance. Ascertain from Table VI the per- centage by weight of solids corresponding to the specific gravity of the diluted solu- tion and calculate the total solids in the original sample by the formula: Solids in original sample=4DS, D being the specific gravity of the diluted solution and S the per cent of solids in the diluted solution. (b) CONFECTIONERY. (1) Lozenges and other pulverizable products. Weigh from 2 to 5 grams of the powdered sample in a tared platinum dish and dry to constant weight at 70° C. in vacuo or in the McGill oven. (2) Semiplastic, sirupy, or pasty products. Measure 25 cc of the 20 per cent solution, or mixture— 2 (c) (1) (b) — into a tared platinum dish containing asbestos fiber and proceed as in 3 (a) (1). »U. S. Dept. of Agr., Div. of Chrm., Bui. 46 revised, p. -js. SACCHARINE PRODUCTS. 45 4. — DETERMINATION OF ASH. Weigh out from 5 to 10 grams of molasses, honey, or sirup, or weigh 5 grams of the pulverizable confectionery, or measure 50 cc of the 20 per cent solution — 2 (c) (1) (6) — into a tared platinum dish; evaporate to dryness on the water bath and burn slowly and cautiously over a low flame. After frothing has ceased, increase the flame and ignite to a white ash at a low, red heat. In igniting saccharine products, frothing .may be largely held in check by direct- ing the flame at first down upon the mass from above instead of from under the dish, as ordinarily, until the material is well charred. 5. — EXAMINATION FOR MINERAL ADULTERANTS. (a) REDUCING TO ASH. Comparatively large quantities of saccharine products may be readily and quickly reduced to an ash for mineral examination without the troublesome frothing that ordinarily ensues in igniting at once with a free flame by proceeding as follows:* Mix 100 grams of molasses, sirup, or honey, or of the confectionery solution (2 (c) (1) (&)) evaporated to sirupy consistency, with about 35 grams of concentrated sulphuric acid in a large porcelain evaporating dish. An electric current is then passed through it while stirring, by placing one platinum electrode in the bottom of the dish near one side and attaching the other to the lower end of the glass rod, with which the contents are stirred. Begin with a current of about 1 ampere and gradu- ally increase to 4.h In from ten to fifteen minutes the mass is reduced to a fine, dry char, which may then be readily burnt to a white ash in the original dish over a free flame or in a muffle. If an electric current is unavailable, treat in a large porcelain evaporating dish 100 grams of the saccharine solution to be ashed, which should be evaporated to sirupy consistency if not already such, with sufficient concentrated sulphuric acid to thor- oughly carbonize the mass, after which ignite in the usual manner. Among the suspected adulterants to be looked for in the ash are salts of tin, used in molasses to bleach or lighten the color, and mineral pigments such as chromate of lead in yellow confectionery, and oxide of iron, the latter being commonly used as an intensifier of or substitute for the natural color of chocolate. (b) DETERMINATION OF TIN IN MOLASSES0 AND OTHER SACCHARINE PRODUCTS.4 Fu.se the ash from a weighed portion of the sample with sodium hydroxid in a silver crucible, dissolve in water and acidulate with hydrochloric acid;6 filter and precipitate the tin from this solution with hydrogen sulphid; wash the precipitate on a filter and dissolve it in an excess of ammonium sulphid. Filter this solution into a tared platinum dish and deposit the tin directly in the dish by electrolysis, using a current of 0.05 ampere. This current may be readily reduced from an ordinary 110- volt street circuit by means of a series of lamps, or a rheostat may readily be improvised for this purpose, consisting of a long, vertical glass tube, sealed at the bottom, containing a column of dilute acid through which the current passes, the » Leach. 32.1 An. Rept. Mass, State Board of Health. (1900.) p. 663. Reprint, p. 37. This method is preferred to the ordinary method of heating with sulphuric: acid, especially in ease of molasses, because, if properly manipulated, it so quietly comes into the form of a very finely divided char or powder, especially adapted for subsequent quick ignition. ' Modified from method of Budde & Schou for determining nitrogen electrolytically. Ztschr.anal. Chem., Is'.i'i, :&S. :;(.-,. •Leach. :;ist An. Kept. Mass. State Board of Health, 1899, p. 625; Hilger & Laband, Ztschr. fvir Unter- snehniiK der Nahr.- u. (Jennss., 1X99, 2, 795. •»This method is npplieahle also to condensed milk, eanncd goods, etc. •See Methods for the .•\miiination of canned vegetables, p. 52. 46 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. resistance being changed by varying the length of the acid column contained between two electrodes immersed therein, one of which is movable. a 6. — DETERMINATION OF ETHER EXTRACT IN CONFECTIONERY. Measure 25 cc of the 20 per cent mixture or solution — 2(c)(l)(6) — into a very thin, readily frangible glass evaporating shell (Hoffmeitter's Schalchen), containing 5 to 7 grams of freshly ignited asbestos fiber; or, if impossible to thus obtain a uniform sample, weigh out 5 grams of the mixed, finely divided sample into a dish, and wash with water into the asbestos in the evaporating shell, using, if necessary, a small por- tion of the asbestos fiber on a stirring rod to transfer the last traces of the sample from dish to shell. Dry to constant weight at 100°, after which cool, wrap loosely in smooth paper, and crush into rather small fragments between the fingers, carefully transferring the pieces with the aid of a camel's hair brush to an extraction tube or a Schleicher and Schull cartridge for fat extraction. Extract with anhydrous ether or with petroleum ether in a continuous extraction apparatus for at least 25 hours. Transfer the solution to a tared flask, evaporate off the ether, dry in an oven at 100° C. to constant weight, and weigh. Unless the ether is absolutely anhydrous, sugar will be dissolved. Ether which gives off hydrogen when treated with metallic sodium is unfit to use without purification. To purify it, let it stand for some time with calcium chlorid in the container, then pour off and distill over metallic sodium. If petroleum ether is employed, it should be purified by fractional distillation so that it boils between 45° and 60° C. and leaves absolutely no residue. 7. — DETERMINATION OF PARAFFIN IN CONFECTIONERY. Add to the ether extract in the flask as above obtained, 10 cc of 95 per cent alco- hol and 2 cc of 1:1 sodium hydroxid solution, connect the flask with a reflux con- denser, and heat for an hour on the water bath or until saponification is complete. Remove the condenser, and allow the flask to remain on the bath till the alcohol is evaporated off and a dry residue is left. Treat the residue with about 40 cc of water and heat on the bath, with frequent shaking, till everything soluble is in solution. Wash into a separatory funnel, cool, and extract with four successive portions of petroleum ether, which are collected in a tared flask or capsule. Remove the petroleum ether by evaporation and dry in the oven to constant weight. It should be noted that any phytosterol or cholesterol present in the fat would come down with the paraffin, but the amount would be so insignificant that except in the most exacting work it may be disregarded. The character of the final residue should, however, be confirmed by determining its melting point and specific gravity, and by subjecting it to examination in the butyro-refractometer. The melting point of paraffin is about 54.5° C.; its specific gravity at 15.5° is from 0.868 to 0.915, and on the refractometer (Zeiss's scale) the reading at 65° C. is from 11 to 14.5. 8. — DETERMINATION OF NITROGEN. Use 5 grams of the sample for this determination, and follow the details of the regular Gunning method. b 9. — DETERMINATION OF STARCH IN CONFECTIONERY. c Measure gradually 25 cc of the 20 per cent solution or uniform mixture (2 (c) (1) (6)) into a hardened filter or Gooch crucible, or transfer by washing 5 grams of the finely powdered substance to the filter or Gooch, and allow the residue on the filter to become air-dried. Extract with 5 successive portions of 10 cc of ether, then wash a Wiley, Principles of Agricultural Analyses, vol. 3, p. 152. b U. S. Dept. of Agr., Div. of Chem., Bui. 46 revised, p. 16. CU. S. Dept. of Agr., Div. of Chem., Bui. 46 revised, p. 25. SACCHARINE PRODUCTS. 47 with 150 cc of 10 per cent alcohol, and finally with 20 cc of strong alcohol. Transfer the residue to a large flask and boil gently for 4 hours with 200 cc of water and 20 cc hydrochloric acid (specific gravity 1.125), the flask being provided with a reflux condenser. Cool, neutralize with sodium hydroxid, add 5 cc of alumina cream, and make up the volume to 250 cc with water. Filter, and determine the dextrose in an aliquot part of the filtrate by Allihn's method, as directed in 13, page 49. The weight of the dextrose multiplied by 0.9 gives the weight of the starch. 10. — POLARIZATION. (a) MOLASSES. Dissolve the normal weight of the sample (26.048 grams for the Schmidt and Haensch polariscope) in water in a 100-cc graduated flask, add an excess of lead sub- acetate solution,* and fill to the mark; shake to insure uniform solution, filter and polarize in a 100-mm tube, multiplying the reading by 2 for the direct polarization. To 50 cc of the filtrate add 5 cc of concentrated hydrochloric acid. Heat slowly to 68° and cool. Polarize in the same tube at the same temperature as before, add 10 per cent to the reading, and multiply by 2 for the invert polarization. The short tube (100-mm) is preferred for polarizing molasses not only on account of the more or less deep color of the clarified solution, but also because a molasses sample containing considerable commercial glucose would not read within the scale limits if the 200-nini tube were employed. It sometimes happens, especially with molasses containing much glucose sirup, that it is impossible to obtain a clear filtrate after clarification with lead subacetate, or that the filtrate, at first Hear, clouds up too quickly to admit of a satisfactory reading. In such cases weigh out a fresh portion of the sample, dilute, and add first the lead subacetate solution ami then enough sodium sulphate or common salt to pn-cipitate the excess of lead. Afterwards fill to the mark and proceed in the regular manner. For medium or light-colored grades of molasses which yield but a small precipitate with lead subacetate, the above method of simple polarization both direct and invert gives results sufficiently accurate for ordinary work. For dark-colored or "black strap" molasses, or wherever extreme accuracy is required, employ the double- dilution method — 10 (c). (b) HONEY, MAPLE SIRUP, AND WATER-SOLUBLE CONFECTIONERY. Follow directions given under "molasses," 10 (a), except that alumina creamb is employed in excess as a clarifier instead of subacetate of lead. (c) CONFK(TIOXEKY CONTAINING STARCH OR INSOLUBLE MATTER. Employ the double-dilution method, c thus making due allowance for the volume of the precipitate. Take half the normal weight of the sample and make up the solution to 100 cc, using the appropriate elarilier (subacetate of lead for dark-colored confectionery or molasses, and alumina cream for light -colored confectionery and honey) . Take the normal weight of the sample and make up a second solution with the clarifier to 100 cc. Filter and obtain direct polariscopic readings of both solu- tions. Invert each in the usual manner and obtain the invert readings of the two. The true direct polarization of the sample is the product of the two direct readings divided by their difference. The true invert polarization is the product of the two invert readings divided by their difference. » Sec footnote, page 84. 11 Prepare by dividing n cold saturated aqueous solution of iiluni into two unequal portions, to the larger of which add a slight excess of ammonium hydroxid. Then add by degrees t lie remaining portion to ;i faint acid reaction. I". S. Kept, of Agr., Div. of (.'hem., Bui. 40 revised, p. 39. • Wiley A: Kwell, Analyst, 1S%, -J|, 184. 48 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. 11. — DETERMINATION OF CANE SUGAR. Use Clerget's formula: s_(a—b] 100 144- 1 where $=per cent of cane sugar, a—direct polarization, 6=invert polarization, 2=temperature. 12. — DETERMINATION OF COMMERCIAL GLUCOSE IN MOLASSES, SIRUPS, AND HONEY. a As to preliminary indications of the presence of commercial glucose in these prod- ucts, a sample of molasses of light color whose normal weight made up to 100 cc and polarized in a 200-mm tube shows a reading much in excess of 60° on the cane- sugar scale is almost sure to contain commercial glucose, while a dark-colored sample of molasses should, if pure, polarize considerably below 50° C. A sample of maple sirup which polarizes much in excess of 65° C on the cane-sugar scale is to be sus- pected of containing commercial glucose, while a sample of honey that polarizes to the right of the zero point is apt to be adulterated either with cane sugar or commercial glucose or both. If any of these products show an invert reading much to the right of the zero point, commercial glucose is almost sure to be present. It is manifestly impossible to determine with absolute accuracy the amount of commercial glucose present by reason of the varying amount of dextrine, maltose, and dextrose present in the adulterant. It is possible, however, in molasses and maple sirup, wherein the amount of invert sugar is so small as not to appreciably affect the result, to estimate approximately the amount of commercial glucose by the following formula: (a-S) 100 175" where G = per cent of commercial glucose, a — direct polarization, S= per cent of cane sugar. In honey, which is composed largely of invert sugar, much closer results are attained by first inverting the sample and obtaining the polariscopic reading at 87° in a tube surrounded by hot water. This reading divided by 175 gives the approxi- mate percentage of commercial glucose in the sample. A large number of samples of commercial glucose have been procured by the department of food and drug inspection of the Massachusetts Board of Health directly from various manufacturers of compound or adulterated honey, molasses, and sirup, to ascertain the grade used by them for this purpose. AR a result of this investigation, it has been found that the grade best adapted by its consistency for admixture with these products, and, indeed, the grade largely, if not univer- sally, used for this purpose, has a density of about 42° Beaume and polarizes on the cane-sugar scale at or about 175° (26.048 grams made up to 100 cc and polarized in a 200-mm tube with the Schmidt & Haensch instrument). From repeated experi- ments made in the writer's laboratory on mixtures containing known proportions of commercial glucose, 175 has been adopted as the most satisfactory factor and has been found to give a very close approximation. b "Leach, 32d An. Kept. Mass. State Board of Health, 1900, p. 658. Reprint, p. 42. bAmong the samples of commercial glucose examined were several obtained from manufacturers of compound jellies and jams, and the examination of these would seem to show that the grade used mostly for this purpose polarizes at or about 150° C. If this is verified, 150 instead of 175 should be used in the above formula when applied to jellies and jams. Theeffectof high temperatures employed in the preparation of this class of goods should not be lost sight of, a factor that does not enter in to disturb the application of the method to adulterated molasses, sirups, and honeys which are mixed in the cold. For chewing gum a grade of commercial glucose is used polarizing at about 185°. SACCHARINE PRODUCTS. 49 For confectionery, as might be expected, from the wide variation in the character and consistency of candies, there is little uniformity in the grade of commercial glucose employed, so that it is not possible as in the case of molasses and honey to calculate the amount present, Nor is it so essential, in view of the fact that commer- cial glucose is rarely regarded as an adulterant of confectionery. 13. — DETERMINATION OF REDUCING SUGARS (ESTIMATED AS DEXTROSE). Treat 5 grams of molasses, sirup, or honey, or 25 cc of the 20 per cent solution or mixture (2 (c) (1) (6)) or 5 grams of the powdered confectionery, with water in a 100-cc graduated flask, using 2 to 5 cc, of lead subacetate solution in the case of molasses or sirup, and 5 cc of alumina cream in the case of honey or confectionery. Make up to 100 cc, filter, take an aliquot part of the filtrate (25 to 50 cc), and make this up to 100 cc, the amount taken being such that when diluted the solution will contain not more than one per cent of dextrose. If lead subacetate has been used to clarify, add to the aliquot part taken, and before dilution, enough sodium sulphate to precipitate the excess of lead, then filter, and make up to the 100-cc mark. Add 30 cc of Fehling's copper solution a to 30 cc of Fehling's alkaline tartarate solu- tion11 in a 250-cc Erlenmeyer flask. c Add 25 cc of the sugar solution (which must not contain more than 1 per cent of reducing sugar) with a burette, heat to boiling and boil exactly 2 minutes. Separate the precipitate as quickly as possible by filter- ing, with the aid of vacuum, through a layer of asbestos about 1 cm thick in a Gooch crucible (which with the asbestos has previously been ignited, cooled, and weighed), washing the cuprous oxide precipitate with boiling distilled water till the wash water ceases to be alkaline. To prepare the asbestos, first boil it with nitric acid (sp. gr. 1.05 to 1.10), washing out the acid with hot water, then boil with a 25 per cent solution of sodium hydroxid and finally wash out the alkali with hot water. Keep the asbestos in water in a wide-mouthed flask or bottle, and transfer it to the Gooch by shaking it up in the water and pouring it quickly into the crucible while under suction. Dry the Gooch with its contents in the oven, and finally heat it at dull redness for fifteen minutes. Transfer to the desiccator, cool, and weigh quickly as cupric oxid. A platinum Gooch may safely be used. If a porcelain (Jooch is employed, extra precautions are necessary in heating to avoid cracking. With porcelain use a muffle. Or, wash with alcohol and ether, dry for 20 minutes at 100° C. and weigh as cuprous ox id. In either case ascertain the weight of reducing sugar, in terms of dextrose, from Table VIII. Or, the copper may be determined from the cuprous oxid in accordance with the official methods. d 14. — DETERMINATION OF ALCOHOL IN SIRUPS USED IN CONFECTIONERY ("BRANDY DROPS").6 Open each drop by cutting off a section with a sharp knife and collect in a beaker the sirup of from 15 to 25 of the drops, which will usually yield from 30 to 50 grains of sirup. Strain the sirup into a tared beaker through a perforated porcelain filter »34.639 grams CuSo45H2O, dissolved in water and diluted to 500 cc. M73 grams of Rochelle salts and 125 grams of potassium hydroxid dissolved in water and diluted to 500 cc. •-• Dcfren, Jour. Am. Chem. Soc.,1896, 18, 749. <» U. 8. Dept. of Agr., Div. of Chcm., Bui. 46, p. 37. •Thirty-second An. Rep. Mass. Board of Health, 1900, p. 757. Reprint, p. 41. 16648— No. 65—02 4 50 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. plate in a funnel to separate from particles of the inclosing shell, and ascertain the weight of the sirup. Dilute with half its volume of water and determine alcohol as directed on page 82. 15. — DETECTION OF COLORING MATTER. Proceed as directed under Coloring matters (p. Ill and following). VII. CANNED VEGETABLES. By L. S. MUNSON, Bureau of Chemistry, U. 8. Department of Agriculture. 1. — GENERAL DISCUSSION. In the investigation of canned vegetables, the proximate analysis is, as a rule, of little value in determining quality; much more depends upon the size, age, and fresh and healthy condition of the vegetables at the time of canning, and the treat- ment during and subsequent to the processes of canning. Hence, methods for the proximate analysis have been given minor consideration to means of determining the quality of the various classes of vegetables and the detection of different forms of adulterants. Much still remains to be done with this class of food, as the time at the disposal of the writer was not sufficient to investigate thoroughly the various problems that presented themselves. 2. — MACROSCOPIC EXAMINATION. A careful macroscopic examination is often of material value in detecting inferior quality with certain classes of vegetables. Upon opening a can, carefully note the appearance of the contents as to quality, color, and size. Any undue corrosion, or blackening of the walls of the can, should also be observed. With mushrooms and capers, no further examination is necessary, as a rule, except the detection of sul- phites in the former. The most common form of mushrooms found upon the market is Agaricus cam- pestris, although different varieties of Boletus are occasionally found. The latter are particularly susceptible to attack by larvae and, except in a fresh state, are seldom free from them. These larva? may readily be seen with the naked eye, or by use of a small hand lens. Many of the mushrooms on the market are of inferior quality, and consist largely of old and broken fragments of tops and stems; occasionally diseased fungi are to be found in the inferior grades. Owing to the nature of this vegetable, only the fresh, healthy specimens should be passed as edible. Capers are the liower buds of Cappares spinosa and, so far as known, are but little liable to adulteration. Owing to their green color, it is always advisable to make a qualitative test for copper. Olives are to be judged entirely by general appearance and by taste. Gherkins and mixed pickles, while not strictly under this class of foods, are considered here along with olives for the sake of completeness; these also are to be judged largely macroscopically and by taste. The use of copper with this class is of frequent occurrence to produce the bright green color; with mixed pickles, where mustard is used, turmeric is frequently added as a coloring agent. It is also advisable to test for aniline dyes where turmeric is not detected. 3. — PREPARATION OF THE SAMPLED Weigh the full can; open, pour off the liquid portion, and reweigh the can; then empty out the solid contents of the can and weigh again. From these weights esti- mate the percentage of liquid and solid contents. By this means, any undue propor- •U. S. Dept. of Agr., Div. of Chem., Bui. 13, pt. 8, p. 1027. CANNED VEGETABLES. 51 tion of liquor, owing to excess of water added, will be detected. Then thoroughly grind the entire contents of the can, cither in a mortar or by means of a food chopper; mix thoroughly and preserve in a glass-stoppered bottle for analysis. Unless the analysis is to be completed within a reasonably short time it is best to dry the entire sample after the determination of moisture is made. After thorough drying, the material is allowed to stand exposed to the air for several hours, or until it has become air dry. A second moisture determination is necessary with this procedure. 4. — PROXIMATE ANALYSIS. For methods of proximate analysis, see Bulletin 13, part 8, U. S. Department of Agriculture, Division of Chemistry, page 1028. 5. — DETECTION OF SACCHARIN. Saccharin is quite extensively used in canned sweet corn as a sweetening agent. For its detection add from 25 to 40 cc of water to about 20 grains of the sample; macerate and strain through muslin; acidify with 2 cc of sulphuric acid (1 to 3) and extract with ether. Separate the ether layer, allow the ether to evaporate sponta- neously, and take up the residue with water. If saccharin lx> present its presence will be indicated by the sweet taste imparted to the water. To conlirm this test add from 1 to 2 grams of sodium hydroxid, and place the dish in an oil bath. Maintain the temperature of the oil at 250° C. for twenty minutes, when the saccharin will be converted into salicylic acid. After cooling and acidifying with sulphuric acid extract in the usual way and test for salicylic acid. This test, of course, presupposes the absence of salicylic acid in the original sample. If salicylic acid is present in the original sample it must be removed before making the test for saccharin. 6. — DETERMINATION OF SULPHITES. Sulphites are largely used with certain classes of vegetables, notably corn and asparagus, as a bleaching agent; they may also find use with this class of foods as a preservative. (a) DISTILLATION METHOD. For their determination place 50 grams of the material in a distilling flask, add about 5 cc of a saturated solution of glacial phosphoric acid, and proceed with the distillation and the titration of the sulphite as directed on p. 90. Where only a qualitative test is desired, take the first few cubic centimeters of the distillate, add a slight excess of iodin solution, boil to expel the excess of iodin, then acidify with hydrochloric acid and add barium chlorid solution. This test is verv delicate and is easily applied. (b) REDUCTION METHOD.* To about 25 grams of the sample placed in a 200-cc Erlenmeyer flask add some pure zinc and several cubic centimeters of hydrochloric acid. In the presence of sulphites, hydrogen sulphid will be generated and may be tested for with lead paper. Traces of metallic sulphids are occasionally present in vegetables, and by the above test will indicate sulphites. Hence positive results obtained by this method should be verified by the distillation method. It is always advisable to make the quantitative determination of sulphites, owing to the danger that the test may be due to traces of sulphids. A trace is not to be considered sufficient either as a bleaching agent or as a preservative. 7. — DETECTION OF PRESERVATIVES. See methods given under Preservatives (p. 107, and following). »I>ept. of Agr., Div. of Clu-m., Bui. 13, pt. «, p. 1032. 52 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. 8. — DETECTION OF COLORING MATTERS. (a) IN TOMATOES11 AND CATSUPS. Most of the coloring matter used in tomatoes is either of coal-tar origin or cochineal, and the general methods given under Coloring Matter (p. — ) maybe applied in these cases. Extract the color from the dried pulp with ordinary alcohol after acidifying with hydrochloric acid and filter. Eosin gives a characteristic fluo- rescent filtrate. Dilute the filtrate with water, extract with amyl alcohol and dye. Cochineal if present is in the form of a lake and will require strong hydro- chloric acid to decompose it. After extraction with amyl alcohol it may be tested with uranium acetate (p. 120). (b) IN PEAS, BEANS, GHERKINS, ETC. Copper salts are most commonly employed in this class of goods, although it is said that zinc is occasionally used. For the qualitative detection, ash from 15 to 20 grams of the sample, either with or without previous treatment with concentrated sulphuric acid (see Heavy Metals below), transfer the ash to a beaker and treat with nitric acid; filter, make the filtrate alkaline with ammonia, and if a precipitate forms filter again. Copper will be indicated by the blue color of the filtrate. If further test is desired acidify with acetic acid, and add potassium ferro-cyanide. Red coloration or precipitate verifies the test. (c) IN MIXED PICKLES, ETC. Turmeric is frequently used and may be identified by the method given under Coloring Matter (p. 120). 9. — DETERMINATION OF TOTAL AND VOLATILE ACIDITY. It is occasionally desirable to determine total acidity in tomatoes and catsups, and volatile acidity in the latter. For this purpose use methods described under Fer- mented and Distilled Liquors (p. 83). Express fixed acids as citric; one 1 cc of decinormal alkali equals .0070 gram of citric acid. Express volatile acids as acetic; 1 cc of decinormal alkali equals .0060 gram of acetic acid. 10. — DETERMINATION OF HEAVY METALS. Owing to the almost universal presence of tin, the frequent occurrence of lead and zinc, and the extensive use of copper as a coloring agent in this class of food materials, the determination of heavy metals is of particular value. The method described by Allen b and modified by Bigelow and Munson, has been used in the laboratory of the Bureau of Chemistry for the determination of heavy metals in canned meats, and may be applied as well to vegetables. Since the work on canned meats, how- ever, the writer has worked out a method that for accuracy and ease of manipulation is preferred to the modified Allen's method. (a) ALLEN'S METHOD, MODIFIED BY BIGELOW AND MUNSON.C Treat 100 grams of the moist material, or 25 grams of the dried material, with about 5 cc of concentrated sulphuric acid and 2 cc of nitric acid. After foaming has ceased add 3 grams of magnesium oxid and mix thoroughly. Then ignite over a Bunsen burner or, preferably, in a muffled furnace, until thoroughly charred. Grind in a mortar, and again ignite to complete combustion. The addition of a few drops of nitric acid may be necessary toward t"he end to complete the operation. Add •Girard and Dupre. Analyses des matieres nlimentaires.etc. b Allen's Coin. Organic Anal. 3d ed. Vol. IV, p. 299. «Jour. Ainer. Chcin. Hoc. Proc. 1900, 22, 32. CANNED VEGETABLES. 53 about 50 cc of hydrochloric; acrid (1:3) and heat to boiling or upon a steam bath for a half hour. Nearly neutralize the acid with sodium hydroxid dilute to 150 cc with water, precipitate with hydrogen sulphid, and filter, after heating fora few moments upon a steam bath to facilitate the separation of the precipitated sulphids. Dry the precipitate and insoluble ash residue, and then fuse in a porcelain crucible with a mixture consisting of one gram each of sodium carbonate, potassium carbonate, and sulphur. Dissolve the fused mass with hot water and filter. Sulphids of lead and copper remain upon the filter. Acidify the filtrate with acetic acid to precipitate the tin sulphid. Collect the tin sulphid upon a filter. Wash thoroughly, and then dis- solve by the aid of heat in a concentrated solution of ferric chlorid. The reduced iron salt is then titrated with potassium dichromate. a One cc of decinormal potas- sium dichromate equals 0.00295 grams of tin. The determination of the tin by ignit- ing and weighing as stannic oxid was found to be unreliable, owing to the precipitation of appreciable amounts of silica that was dissolved by the mixed carbonates from the porcelain crucible. Determine the copper and lead, which remain as insoluble sulphids after the fusion, and the zinc, which remains in the original filtrate, according to the scheme described under the following method. (b) MUNSON'S METHOD. Treat 100 grams of the moist sample after evaporation to dryness, or 25 grams of the dry sample in a four-inch porcelain evaporating dish with sufficient concentrated sul- phuric acid to thoroughly carbonize the mass. Usually from 10 to 15 cc are sufficient for this purpose. Gently heat over a Bunsen burner until all danger of foaming is past, which will require not more than three minutes; then transfer the dish to a muhMe furnace and keep it at a low red heat until all organic matter is destroyed. It is occasionally found necessary to add a few drops of nitric acid to completely destroy organic matter. When the material is completely ashed, allow the dish to cool; add 25 cc of hydrochloric; acid (1 to 8) and evaporate on a water bath to dryriess; take up with water and acidify with two or three drops of hydrochloric acid. Transfer to a beaker without filtering and treat with hydrogen sulphid. After heating upon a water bath for a few minutes the precipitate and the insoluble residue are col- lected upon a filter. The precipitate and residue may contain sulphids of tin, lead, and copper, and oxid of tin; the filtrate will contain any zinc that is present. Fuse the sulphid precipitate and insoluble ash residue with about three grams of caustic soda in a silver crucible fora half hour to render soluble any insoluble tin compounds. Dissolve the mass with hot water and slightly acidify with hydrochloric acid. Again treat with hydrogen sulphid without filtering. By this treatment all the tin is thrown down as sulphid with the sulphids of copper and lead. Collect the pre- cipitate upon a filter and wash thoroughly with hot water. The filtrate may be rejected. To separate the tin sulphid from those of copper and lead, wash several times upon the filter with separate portions of 10 cc of strong boiling ammonium sul- phid. Usually 50 cc of the ammonium sulphid will be found sufficient to completely dissolve all tin sulphid; but portions of the filtrate should be tested to make sure of this point. The filtrate is then made acid with hydrochloric acid to precipitate the tin sulphid, which, after standing for a few moments, is collected upon anashless fil- ter, ignited, and weighed as stannic oxid. Treat the insoluble residue remaining from the ammonium sulphid washing with nitric acid, filter, wash, nearly neutralize with ammonia the excess of mineral acid, and add ammonium acetate, as there is usually a small amount of iron present. If any iron salt precipitates, filter, wash and divide the filtrate for the determinations of copper and lead. In the absence of lead, copper may be determined electrolytic- ally, or it may he titrated with potassium cyanid. Unless added as a coloring agent, copper will seldom he present in sufficient quantity to warrant its determination. 'Suttnii, Voliimrtnr Analysis, sth i-d., p. 54 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. Precipitate lead with potassium chromate in an acetic acid solution; and weigh upon a tared filter as lead chromate. Evaporate the nitrate from the hydrogen sulphid precipitate to about 60 cc; add bromin water to oxidize the iron salts, and any remaining hydrogen sulphid. Boil off the excess of bromin and, unless the solution is distinctly yellow, add a few drops of concentrated solution of ferric chlorid to make it so. Nearly neutralize the mineral acid with ammonia, and add ammonium acetate to precipitate iron phosphate and excess of iron. Filter and thoroughly wash the precipitate. To the filtrate, made distinctly acid with acetic acid and boiled, add hydrogen sulphid to precipi- tate zinc. Unless the zinc sulphid comes down white, it should be dissolved, again treated with ammonium acetate to remove traces of iron, and re-precipitated as sul- phid. Finally collect the zinc sulphid upon an ashless filter, ignite and weigh as zinc oxid. 11. — "SOAKED" VEGETABLES. A class of canned vegetables commercially known as " soaked" goods is now very commonly founcl upon the market, and constitutes the cheapest grade of vegetables sold. So far as the writer's experience goes, only peas, beans, and corn, or combina- tions of these three, are found in this class. The material used for ''soaked" prod- ucts are the ordinary matured peas and beans, such as are used for seed, or are sold dried upon the market, and corn that has passed the stage when it can be supplied for the green market. The particular advantage in canning these goods is that the season for green vegetables passes rapidly, and in case the supply is greater than the canneries can handle, recourse is made to the packing of the matured product. Besides, these dried materials may be kept for some time, and thus serve to keep the canneries in operation during the less busy season. So far as the composition of this class of canned vegetables is concerned, it prob- ably varies but little from that of the younger vegetables, yet it does not possess the value as a relish that the former has. In the mature vegetables the percentage of total solids is much higher than in the young and more succulent vegetables, and this condition holds in the canned goods if only the solid contents of the can are con- sidered. However, in a large number of samples of "soaked" goods examined, the proportion of liquid to solid portion was exceedingly high; so that when the entire contents of the can were taken the per cent of total solids was about normal for the green vegetables. The detection of "soaked" vegetables is not a difficult matter for one who has had experience with this class of goods, but for a layman the task may not be so easy. As stated above, the high percentage of solids in the solid portion of the can is characteristic. Soaked peas and beans lose much, if not all, of their green color, and have the general appearance of the well-matured product. Their cotyledons are well formed, firm and mealy. With the pea the caulicle is particularly prominent, the process of soaking having been sufficient to start its development. With corn, the kernel is plump and hard and lacking in milky consistency. The succulence so characteristic of the green pea, bean, and corn is entirely lacking. The sense of taste may also be applied in the detection of this class of goods. From their nature it is difficult to apply specific tests, but a little practice will enable the analyst to detect them with reasonable certainty. VIII.— COCOA AND ITS PREPARATIONS. By F. T. HARRISON, District Analyst, London, Ontario. It has been found impossible to prepare the report on this subject this year. The heading is inserted here to preserve its proper order. SPICES. 55 IX.— TEA AND COFFEE, By W. H. ELLIS, District Analyst, Toronto, Canada. It has been found impossible to prepare the report on this subject this year. The heading is inserted here to preserve its proper order. X. SPICES. By A. L. WINTON, Oiemist of State Experiment Station, New Haven, Conn. 1. — GENERAL DISCUSSION. The microscope is a most valuable means of detecting adulterants of vegetable origin in spices, as it usually discloses the particular adulterant present, even when in small amount. Quantitative determinations are made, either to corroborate the results of the micro- scopical examination, or to detect exhausted spices, mineral matter, and other adul- terants which do not have distinctive microscopic characters. a 2. — PREPARATION OK SAMPLES. Grind the sample so as to pass a sieve with round holes one millimeter in diameter. For the determination of starch in pepper by the diastase method, reduce a portion of the sample to an impalpable powder, by grinding in a mortar. 3. — DETERMINATION OK WATER." Dry two grams at 110° C. to constant weight. From the loss in weight thus sustained subtract the amount of volatile ether extract determined as below described. This method, described by Richardson,1' gives a close approximation to the true percent- age of moisture. 4. — DETERMINATION OF TOTAL ASH. Follow the method of the Association.0 If calcium carbonate is present, care must be taken to burn the material and also the residue after exhaustion with water, at a heat below redness, thus avoiding loss of carbonic acid of the carbonate. When leaching with water is necessary, it is advisable to add a few drops of ammonium carbonate solution before evaporation. 5. — DKTKKM i NATION OF ASH SOLUBLE IN WATER. Boil the ash prepared as above with 50 cc of water, collect the insoluble portion in a Gooch crucible, wash with hot water, dry, ignite, and weigh. d Subtract the percentage of insoluble ash thus determined from the percentage of total ash, thus obtaining the percentage of water-soluble ash. 6. — DETERMINATION OF "SAND" OR ASH INSOLUBLE IN HYDROCHLORIC ACID. Incinerate 2 grams of the material as above directed, boil with 25 cc of 10 per cent hydrochloric acid (sp.gr. 1.050) for 5 minutes, collect the insoluble matter in a Gooch crucible, wash -with hot water, ignite, and weigh. • See also Appendix, p. !.>_'. *U.S.Dept.Agr..l>iv.rhrm..Bul. lit. I'art 2, p. ir..\ "U.S. Dept.of Agr.,I>iv.nf Chcni., Bui. If. revised, p. 23. dConn. Agr. Kxpt.Sia. IN-pi. iv.is, p. IN;. 56 PROVISIONAL METHODS FOE ANALYSIS OF FOODS. 7. — DETERMINATION OF LIME. Calcium sulphate and carbonate are frequently used as adulterants, and are also present in appreciable amount in limed nutmegs, ginger, etc. In the presence of calcium sulphate, the water solution gives tests for both lime and sulphuric acid. Samples containing a considerable amount of carbonate effervesce on addition cf 10 per cent hydrochloric acid. Determine lime in the ash, after separation of iron and alumina phosphates, as described under Baking Powder (p. 106.) 8. — DETERMINATION OF TOTAL SULPHUR. a (For mustard and samples adulterated with calcium sulphate.) Convert about 10 grams of sodium peroxid into hydroxid in a nickel crucible by adding a little water and boiling over a low flame until the excess of water is expelled. Stir 1 gram of the material into the slightly cooled hydroxid and oxidize by gradually raising the heat and adding small portions of sodium peroxid until the oxidation is complete. Dissolve the fused mass in 400 cc of water, acidify strongly with hydrochloric acid, boil until the excess of peroxid is destroyed and chlorin expelled, filter through pure paper, make neutral with ammonia, and add an excess of 4 cc of concentrated hydrochloric acid. From the boiling solution pre- cipitate sulphuric acid by gradually adding a solution containing 1 gram of barium chlorid. After standing over night, in a warm place, filter the barium sulphate, wash, ignite, and weigh. Osborne has found commercial sodium peroxid to be freer from sulphur than most preparations of so-called chemically pure sodium hydroxid made from the metal, and as the former is very much cheaper than the latter, it is advantageous to use it as here described. 9. — DETERMINATION OF CARBON DIOXID. ( For samples adulterated with calcium carbonate. ) Proceed as directed under total carbon dioxid in Baking Powder (p. 98 and following). 10. — DETERMINATION OF VOLATILE AND NONVOLATILE ETHER EXTRACT. b Extract 2 grams of the ground material for 20 hours, in a continuous extraction apparatus, with absolute ether. c Transfer the ethereal solution to a tared capsule and allow to evaporate at room temperature. Let stand 18 hours over sulphuric acid and weigh the total ether extract. Heat the extract gradually to 100° C. , continue the heating at that temperature for 6 hours, and then at 110°, until the weight becomes constant. The loss is volatile oil; the residue, nonvolatile ether extract. 11. — DETERMINATION OF ALCOHOL EXTRACT. d Place 2 grams of material in a 100-cc flask and fill to the mark with 95 per cent alcohol by volume (sp. gr. 0.815 at 15.5° C. ). Stopper, shake at intervals of 30 minutes for 8 hours, and allow to stand 16 additional hours without shaking. Filter the extract through a dry filter, evaporate 50 cc to dryness in a flat-bottomed dish on a water bath, and heat to constant weight at 110° C. The result is practically the same when the time of extraction is 48 instead of 24 hours. Win ton, Ogden, and Mitchell, c who describe this method, do not claim that it extracts all matter soluble in alcohol; in fact, the residue separated from the solutions by filtration, when » Osborne, Conn. Agr. Expt. Sta. Kept., 1900, p. 445. b Richardson, U. S. Dept. ot Agr., Div. of Chem., Bui. 13, Part 2, p. 165. c See Appendix, pp. 153 and 154. dSee Appendix, p. 154. •Conn. Agr. Kxpt. Sta. Ilcj»t., ISM, p. 187. or THE . UNIVERSITY , Kn SPICES. \ or / 57 FQ> treated for 24 additional hours with a fresh portion of alcohol, yielded, in their experience, small additional amounts of extract. The method, however, gives nearly the full amount of extract and the results are concordant; whereas, extraction in a Soxhlet apparatus, if continued until no more extract is removed, is an interminable operation, and, as it is difficult to keep the strength and temperature of the extract- ing alcohol constant, gives results far from satisfactory. 12. — DETERMINATION OK COPPER-REDUCING MATTERS BY DIRECT INVERSION. a Extract 4 grams of the material on a Schleicher and Schuell's No. 589 blue-ribbon washed filter, or some other filter that will completely retain the smallest starch granules, with five successive portions of 10 cc of ether. After the ether has evap- orated, wash with 150 cc of 10 per cent (by volume) alcohol. Weak alcohol is employed instead of water, because, as pointed out by Lindsey, it is not so liable to carry starch granules through the paper. Since it is not possible to wash samples of Batavia cassia with water or dilute alco- hol, owing to the formation of a glutinous mass which clogs the filter, for the sake of uniformity, all preliminary washing is best omitted in determinations made on all varieties of cassia, as well as on cassia buds and cinnamon. Carefully wash the residue from the paper into a 500-cc flask, with 200 cc of water, using a small wash bottle, and~gently rubbing the paper with the tip of the finger. Convert the starch into dextrose by the Sachsse method,1' as follows: Add 20 cc of 25 per cent hydrochloric acid (sp. gr. 1.125) and heat for three hours on a boiling water bath. Cool the solution nearly, but not quite, neutralize with sodium hydroxid solution, make up to 500 cc, and filter through a dry paper. Determine reducing matters by the Allihn method,0 as follows: Mix 30 cc of a solution containing 17:5 grams of Rochelle salts and 125 grains of caustic potash in 500 cc of water, and .">0 cc of a solution of 34.69 grams of pure crystal- lized copper sulphate in 500 cc of water, in a beaker of 200 cc capacity and heat to boiling. To the boiling liquid, without delay, add 25 cc of the solution to be exam- ined, and continue the heating until boiling logins again. After the reduced copper suboxid has settled, collect on a < Jooch crucible, dry at a moderate heat, and finally heat for three to five minutes at dull redness, taking care to avoid a bright red heat and to allow access of sufficient air to complete the oxidation to copper ox id (after Bartlettd). After weighing, repeat the heating to make certain that the oxidation is complete. From the weight of copper oxid calculate the weight of metallic copper, using the factor 0.7986, and find the corresponding amount of dextrose in Table VIII. To obtain the corresponding weight of starch, multiply the weight of dextrose by 0.9. If desired, the copper may be weighed as Cu.2O after washing with alcohol and drying at 100° C., or it may be determined electrolytically by one of the official methods. To prepare asbestos pulp for use in the Gooch crucible, cut woolly asbestos (best quality) into small pieces, boil with hydrochloric acid, and wash free from acid and tine particles on a sieve with one-mm meshes. Woolly asbestos of suitable quality, when packed in the crucibles with the aid of a blunt glass rod, retains completely the finely divided copper suboxid, which is not true of the variety usually employed in filtering coarser precipitates. Copper-reducing matters by direct inversion was first determined in pepper by » U. S. Drpt. of Atfr., Div. of Chrin., Bui. 13: p. 166. Conn. Agr. Expt. Sta. Kept., 1898, p. 187. Srr also Appendix, p. 1 .">•!. bChcin. < 'rut rail)!. 1S77, 8, T.\'l. ••Jour, prakl. Chcm.. ISSO. N. F., 22, .VJ. •' Maine A.^r. Kxpt. Sta. lii-p;.. is.s.s, p. 207. 58 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. Lenz. a Although useful, the results are not of as great value as those by the dias- tase method. 13. — DETERMINATION OF STARCH BY DIASTASE METHOD. b Extract 4 grams of the finely pulverized material with ether and 10 per cent alcohol, as described in the preceding section. Carefully wash the wet residue from the paper into a beaker with 100 cc of water, heat on an asbestos plate to boiling with constant stirring, and continue the boiling and stirring thirty minutes. Replace the water lost by evaporation, and immerse the beaker in a water bath kept at from 55 to 60°. When the liquid has cooled to the temperature of the bath, add 10 cc of fresh extract of malt (prepared by digesting for two or three hours 100 grams of p,>wdered fresh malt with 1,000 cc of water and filtering), and digest the mixture for one hour, with occasional stirring. Boil a second time for fifteen minutes, cool, and digest as before with another 10-cc portion of malt extract. Heat to boiling the third time, cool, and make up the liquid to 250 cc in a graduated flask, filter through a dry paper, and remove 200 cc of the filtrate to a 500-cc flask. Conduct the inversion with acid, and determine the reducing power of the solution, as already described under "Copper-reducing matters by direct inversion," making a correction for the copper reduced by the added malt extract, as determined by blank analyses. The residue after the malt digestion, when examined microscopically, must be entirely free from starch. Results by Winton, Ogden, and Mitchell c show that cayenne pepper, mustard, and certain other materials, which are practically free from starch, yield very little or no copper-reducing matter, when treated by the method just described. This treatment is, therefore, without effect on the cellulose, pentosans, or other matters in the spices named, although they yield copper-reducing material on treatment with acid. On the other hand, in decorticated white pepper and Jamaica ginger, which con- tain little besides starch that is affected by acid, practically the same results are obtained by the diastase method as by direct inversion with acids. This determination of starch is very valuable as a means of detecting starchy adulterants in spices normally free from starch and nonstarchy adulterants in spices which contain starch. 14. — DETERMINATION OF CRUDE FIBER. d The method is that adopted by the Association of Official Agricultural Chemists for the analysis of cattle foods, except that the fiber is filtered and weighed on a paper rather than on a Gooch crucible, since the latter is liable to clog, rendering filtration impossible. Place the residue from the determination of ether extract in a 500-cc Erlenmeyer flask, and add 200 cc of boiling 1.25 per cent sulphuric acid. Loosely cover the flask, heat at once to gentle boiling, and continue the boiling thirty minutes. Filter on a paper, wash with hot water, and rinse back into the same flask with 200 cc of boiling 1.25 per cent sodium hydroxid solution, nearly free from carbonate. After boiling, as before, for thirty minutes, collect the fiber on a weighed paper, thoroughly wash with hot water, and finally with a little alco- hol and ether. Dry to constant weight at 100° C., and weigh. Deduct the amount of ash in the fiber, as determined by incineration, from the total weight. Determine the loss in weight sustained by the paper on treatment with sodium- hydroxid solution, alcohol and ether, and introduce the necessary correction. »Ztschr. anal. Chem., 1884, 23, 501. '•Maercker, Handbuch der Spiritusfabrikation, 7th ed., 1898, p. 109; Wiley, Principles and Practice of Agricultural Analysis, 1898, Vol. Ill, p. 198. «Conn. Agr. Expt. Sta. Kept., 1898, p. 189. d See Appendix, pp. 154 and 155. SPICES. 59 15. — DETERMINATION OF NITROGEN. (a) KJELDAHL METHOD. ( For all spices except black and white pepper. ) See methods of the Association of Official Agricultural Chemists. a (b) GUNNING-ARNOLD METHOD. ( For black and white pepper. ) Owing to the presence of piperine, the Gunning- Arnold method b must be used to determine nitrogen in both black and white pepper. Mix 1 gram of the material in a 600-cc Jena0 flask with 1 gram of copper sulphate, l.gram of mercuric oxid, 15 to 18 grams of potassium sulphate, and 25 cc of sulphuric acid. After heating gently until frothing ceases, boil the mixture from two to four hours. When nearly cool, add about 300 cc of water, 50 cc of potassium sulphid solution (40:1,000), and sodium hydroxid solution to alkaline reaction. Distill into standard acid and titrate with standard alkali, as usual. 16. — DETERMINATION OF NITROGEN IN NON- VOLATILE ETHER EXTRACT. — WINTON, OGDEN, AND MITCHELL METHOD. (For black Jour. Am, Chern. Soc., 1898, 20, 5. 64 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. 8. — DETERMINATION OF VOLATILE AND FIXED ACIDS. (a) VOLATILE ACIDS. Heat 15 cc of the vinegar to boiling in a flask, adding a little tannin if foaming occurs; then lower the flame and pass a current of steam through the vinegar to a condenser. Continue the operation until 15 cc of distillate shows no acidity upon a test with sensitive litmus paper. Titrate the combined distillate with half-normal sodium hydroxid, using phenolphthalein as indicator. The number of cubic centi- meters of alkali required, multiplied by 0.03, gives the weight of volatile acids, expressed as grams of acetic acid. (b) FIXED ACIDS. Deduct volatile acids from total acids and multiply the remainder by 0.817 for sulphuric acid, or 1.117 for malic acid. Or dilute the nonvolatile residue from the distillation with water until the solution appears nearly clear against a white back- ground. Titrate with half-normal sodium hydroxid, using phenolphthalein as indi- cator, as in case of the volatile acids. The weight of fixed acids, calculated to sul- phuric or malic, is calculated by the factors given above. When 15 cc are taken, multiply the number of cubic centimeters of half-normal alkali solution employed by 0.163 for the percentage of fixed acids expressed in terms of sulphuric acid (H2SO4), or by 0.223 to express in terms of malic acid. 9. — DETECTION OF FREE MINERAL ACIDS. (a) FIRST METHOD. a Prepare an extract of logwood by pouring 100 cc of boiling water upon 2 grams of fresh logwood chips, allowing the decoction to stand for a few hours and filtering. Separate drops are spotted on a porcelain surface and dried over a water or steam bath. Add to one of the spots a drop of the vinegar to be tested (after concentration, if thought desirable); again evaporate to dryness. A yellow tint remains if free mineral acids are absent, a red tint if present. (b) SECOND METHOD. To 5 cc of vinegar add 5 or 10 cc of water; after mixing well, add 4 or 5 drops of an aqueous solution of methyl-violet (one part of methyl- violet 2B in 10,000 parts of water). The occurrence of a blue or green color indicates the presence of a free mineral acid. 10. — DETERMINATION OF FREE MINERAL ACIDS. (a) IIILGER'S METHOD. Neutralize 20 cc of the vinegar exactly with half normal alkali, the end reaction being determined by the action of drops of the liquid upon sensitive violet litmus paper. Evaporate the neutral liquid to one-tenth volume in a porcelain dish, add a few drops of methyl- violet solution (that mentioned in paragraph 9), dilute with 3 or 4 cc of water, if needful, to secure a clear solution, bring to boiling, and titrate with half normal sulphuric acid till a green or blue color begins to appear. The difference, in cubic centimeters, between the seminormal alkaline and acid reagents added, multiplied by the factor 0.1225, expresses the percentage of mineral acid present, in terms of sulphuric acid (H2SO4). (b) HEHNER'S METHOD. To a weighed quantity of the sample add excess of decinormal alkali, evaporate to dryness, incinerate and titrate the ash with decinormal acid. The difference between 'Ashby, Allen's Com. Org. Anal. 2d ed., vol. I, p, VINEGAR. 65 the number of cubic centimeters of alkali added in the first place and the number of cubic centimeters needed to titrate the ash represents the equivalent of the free acid present. 11. — DETERMINATION OF OXALIC ACID. The presence of oxalic acid may be detected and its quantity determined by addition of a solution of calcium sulphate to a measured quantity of the vinegar. 12. — DETERMINATION OF ALCOHOL. Domestic fruit vinegars are often incompletely acetified; if the specific gravity be abnormally low, a determination of the alcohol present is desirable. Owing to the small quantities usually present, it is best to concentrate the distillates. Carefully neutralize 100 cc of the vinegar and distill over 40 cc; redistill the distillate until 20 cc has passed over; cool to 15.5° C. and make up to 20 cc with distilled water. Determine the specific gravity by means of a pycnometer and calculate the percentage by weight, by Table II. The percentage in the last distillate, divided by 5, represents the amount in the original vinegar. 13. — DETECTION OF COLORING MATTERS. The principal coloring matter used for tinting imitation vinegars in America is caramel. To detect this use Amthor's method (p. 120) . A further test of the caramel may be made by boiling the aqueous solution of a portion of the precipitate obtained by Amthor's method, with Fehling's solution; caramel has a reducing action. In the case of wine vinegars, test for foreign red colors may be made according to the methods given on p. Ill and following. 14. — DETECTION OF FOREIGN PUNGENT MATERIALS. Exactly neutralize a portion of the vinegar (the residue from determination of total acidity may be used), evaporate off a portion of the water, and test the concen- trated solution by taste for pungent substances; then agitate the liquid with ether, in a separatory funnel, remove and evaporate the ethereal layer, and apply the same test to the residual ethereal extract. The perfect identification of the specific substance employed is rarely attained. 15.— DETECTION AND DETERMINATION OF METALLIC POISONS. Evaporate from 200 to 500 cc to dryness. In case of cider, malt, and other vine- gars rich in solids, add a little sodium hydroxid and potassium nitrate, and incinerate. The ash thus obtained, or the solids themselves, in case of vinegars low in extract, is carefully dissolved in hydrochloric acid and the solution subjected to examination by methods indicated for the analysis of canned vegetables (p. 52). 16. — DETECTION OF PRESERVATIVES. Preservatives are sometimes, though rarely, added to vinegar. Salicylic and ben- zoic acids may be separated by agitation with ether and detected in the residue left upon evaporation of the ether. Boric acid may be detected in the ash left upon the evaporation and incineration of the vinegar after neutralization by alkali. Most of the tests for the detection of formaldehyde are excluded from use in test- ing vinegars, since the indicative reactions are usually produced by acetaldehyde also, which is frequently present in normal vinegar. From 100 cc of the vinegar distill 20 cc. To a portion of the distillate add a few drops of milk; float the liquid upon 90 to 94 per cent sulphuric acid to which a little ferric chlorid has previously been added. A violet ring appears at the point of separation of the liquids, if formaldehyde is present. Acetaldehyde does not produce this reaction, the color being yellowish green changing to brown. 16648— No. 65—02 5 66 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. A portion of the distillate prepared as above may, after the addition of a few drops of milk, be treated with a drop of concentrated aqueous ferric chlorid solution, agi- tated and well mixed with a nearly equal volume of concentrated hydrochloric acid. Warm below boiling with constant agitation. Shortly before ebullition a purple coloration of the casein appears, if formaldehyde be present; it is not produced by acetaldehyde. 17. — DETERMINATION OF THE SOURCE OF A VINEGAR. It is not always possible to make this distinction with entire certainty. The prin- cipal vinegar of the United States is cider vinegar, though malt vinegar finds prefer- ence with many. The substitutes are chiefly (a) low wine vinegar, either sold under the name "white wine vinegar" or colored by addition of caramel, or even given color and body by addition of cheap apple jelly; (b) vinegar from sugarhouse wastes; (c) wood vinegar, or preparations from vinegar essence, with or without coloring matters. Grape, or true " wine vinegar, " is important in few localities outside of California. Glucose vinegar is sometimes found. The nature of the vinegar is commonly indicated, if it be pure of its kind, by its flavor and odor. The fruity quality of cider vinegar is usually very conspicuous; the odor of malt vinegar is characteristic; and impure wood vinegar often shows a very perceptible empyreumatic quality. Even when these qualities are distinctly indic- ative of the source of the vinegar, additional evidence is desirable for legal proof; often slight impurities mask them. The quantity of the solids is often distinctive. The range for the principal vinegars is: Cider vinegar, 1.18 to 8.04; average, about 2.5. Malt vinegar, 1.75 to 6.0; average, about 3.0. Spirit vinegar, 0.13 to 0.78; average, about 0.3. Wine vinegar, 1.38 to 3.19; average, 1.9. a The quantity of solids in sugar and glucose vinegars varies with the conditions of manufacture, sometimes corresponding closely with that of fruit vinegars. That of wood vinegar resembles the quantity in spirit vinegars. By the addition of foreign solids to spirit or wood vinegar the value of this criterion is often destroyed. The quality of the vinegar solids, as a whole, is usually characteristic. The consistency of that from cider is thick and viscid or mucilaginous; that from sugar, glucose, or malt is somewhat more glutinous. The odor of baked apples is notable in cider- vinegar solids, that of molasses is often apparent in sugar-house vinegar, and that of malt vinegar is usually distinctive. The flavor of cider-vinegar solids is acid and somewhat astringent; in these respects wine vinegar resembles it. The bitter taste of caramel is usually observed in sugar-house vinegar solids and in those from col- ored spirit and wood vinegars. On burning the solids, the apple odor is developed by cider vinegar, that of burnt sugar by sugar-house vinegar, and that of scorched cornb by glucose vinegar. The solubility of the solids in alcohol marks fruit vinegars — except a granular residue of tartar in grape vinegar — while the solids of malt and glucose vinegars are only very slightly dissolved. c By addition of cheap cider jelly to spirit or wood vinegar, the characteristic apple quality is, however, given to the vinegar solids. d The quantity of the ash is useful in distinguishing spirit and wood vinegars from fruit and malt vinegars, the quantity in the former case rarely exceeding 0.1 per cent; in the latter rarely falling below 0.2; the range for pure cider vinegar is 0.19 to 0.57; average about 0.35 per cent. The quality of the ash is far more indicative. That of fruit vinegars and malt vine- gars is distinctly alkaline; that of spirit and wood vinegars very slightly so. The 'According to Blyth. Eckenroth gives 0.35 to 1.51 per cent. i> Davenport, 26th Ann. Kept. Milk Inspector, City of Boston, 1885. "Allen, Com. Organic Anal., Vol. I, p. 389. a Frear, Kept. Pa. Dept. of Agr., 1898, p. 138; Leach, Kept. Mass. State Bd. of Health, 1898, p 633. VINEGAR. 67 expressed in terms indicated in the previously described methods is, for cider vinegar 26 to 65, average 39; for malt vinegar 5.5, and for spirit vinegar 1.1. '/'///• (jii(ii//it>i of frfiosp'lioric s7; Hehner, Vtjschr. Chem., Nahr, 1893,7, 194. '• Davenport, 26th Ann. Kept. Milk Inspector, City of Boston, 1885. "Frear, Kept. Pa. of Dept. of Agr., 1898, p. 145; C. A. Browne, jr., Kept. Pa. State College Agr. Exp. Station, 1900, p. 2<;n; also Bulletin 58, Pa. Dept. of Agr., p. 43; Doolittle & Hess, Jour. Am. Chem. Soc., 1900, 22, 19; Allen, Com'l Organic Analysis, second edition, Vol. I, p. 81; Von Bitteryst, Rev. nils, internal., 1894, 7, 151. •i Wiley, Agricultural Analysis, Vol. Ill, p. LW. •Kept. Pa. State College Agr. Kxpt. sta.. I'.xx), p. 269-274; Cf. also, Frear, Kept. Pa. Dept. of Agr., 1898, p. 138 and following, and Browne, Bui. 58, Pa. Dept. of Agr., for comparative data. 68 PEOVISIONAL METHODS FOK ANALYSIS OF FOODS. 4.6 to 17.1, average 9.0; that of pure spirit — malt and wine vinegar— averages 5 to 8; but upon addition of cider jelly to a vinegar, low in solids, the ratio becomes 17.1 to 80. The quantity of nitrogen serves to distinguish malt vinegars from such as are derived from saccharine liquids, low wines, or wood acids. Calculated as albuminoids, the amount in malt vinegars is 0.65 to 0.7 per cent;a in cider vinegars, 0.006 to 0.024 per cent;b in sugar, glucose, spirit, and wood vinegars, much less. The presence of alcohol in vinegars derived from alcoholic liquids often serves to distinguish them from wood vinegar; its absence is not conclusive against their deri- vation from the former class of materials. The presence of tartar distinguishes wine vinegar, though its absence is not con- clusive of other origin. c Allen's method for this test is as follows: d Treat the residue left from evaporation of the vinegar, with alcohol; a granular residue of tartar re- mains undissolved; to prove its character, pour off the alcohol and dissolve the residue in a small quantity of hot water. On cooling the aqueous solution, and stirring the sides of the vessel with a glass rod, the acid tartrate of potassium will be deposited in streaks on the track of the rod. An addition of an equal bulk of alcohol makes the reaction more delicate. The adulteration of wine vinegar by addition of free tartaric acid is proved in a similar manner, the alcoholic solution of the extract is treated with an alcoholic solution of potassium acetate; upon stirring the mixture with a glass rod in a beaker, streaks and probably a distinct precipitate of tartar will be deposited. Quantitative results can be obtained upon titration of the precipitate by standard alkali. • The presence of malic acid distinguishes cider vinegars, though the quantity is often small. Failure to obtain a precipitate upon the addition of a few drops of neutral lead acetate to 10 cc of a vinegar, proves it not to be cider vinegar; if a precipitate be obtained, parallel tests with silver nitrate and barium chlorid to determine the absence of chlorids and sulphates should be made, before the presence of malic acid be considered proved. Dextrin is often found in glucose vinegar and is precipitated from the concentrated vinegar upon addition of three or four four volumes of strong alcohol; the precipitate may be identified by the physical properties and by its color reaction with iodin solution. Dextrin is also of general occurrence in malt vinegar. Wood vinegar is quite commonly marked by the presence of empyreumatic matters; these are sometimes sufficient to impart their characteristic flavor to the vinegar. It has been recommended that the method of Cazeneuve and Cotton e be used for their detection; this depends upon the immediate reduction of 1 cc of a 0.1 per cent solu- tion of potassium permanganate when added to 10 cc of the liquid to be tested. Obviously this test is not applicable in the presence of caramel or the reducing sugars of fruit and malt vinegars; both the distillate and the ether extract of cider vinegars cause rapid reduction. The test is not applicable therefore to mixtures of wood vine- gar with that from other sources, but may be useful in completing the examination of a vinegar shown by other evidence to be wood vinegar. Microscopic examination may establish the absence of alcoholic and acetic ferments; in such event, the article is shown to be distilled vinegar. •Blyth, Foods, Their Comp. and Anal., 4th edition, p. 587. »>Frear, Kept. Pa. Dept. of Agr., 1898, p. 145. 'Tretzol (Forschungsber, 1896, 3, 186: Vtjschr. Chem. Nahr., 1898, 11, 257) states that true wine vine- gars are occasionally found without tartar or more than traces of it. H. Eckenroth (Pharm. Ztg., 1889, 34, 14; Vtjschr. Chem. Nahr., 1891, 4, 88) claims that it is always found, if from 500 cc to 1 liter of the vinegar be used for the test. Von Bitteryst (Op. cit., 1896, 9, 425) gives 0.04 gram per 100 cc as a minimum. ''Commercial Organic Analysis, 2d ed., vol. 1, p. 389. « Vereinbarungen zur einheitlichen Untersuchung und Beurtheilung von Nahrungs— und Genussimitteln, II, 83. Bui. soc. chim., 1881, [2], 36, 102. FLA YOKING EXTAKCTS. 69 XII.-FLA YOKING EXTRACTS. By A. S. MITCHELL, Chemist of State Dairy and Food Commission, Milwaukee, Wis. Flavoring extracts consist of three classes of preparations — tinctures, spirits, and artificial essences. Each class needs specific treatment, varying in detail with the object sought. In quantitative examination of either tincture of vanilla or spirits of lemon, it is essential to carry out comparative tests upon similar products of known purity and strength. Many of the methods recommended for lemon may be readily adapted to the examination of other spirits containing volatile oils. (A) VANILLA AND ITS SUBSTITUTES. 1. — DETERMINATION OF TOTAL SOLIDS. Weigh 25 grams of the extract into a large, flat-bottomed dish which contains enough freshly ignited asbestos to absorb it; dry from twenty to twenty-four hours in a water-jacketed oven. 2. — DETERMINATION OF ASH. Weigh about 10 grams of the extract in a flat-bottomed platinum dish, evaporate to dryness on a water bath, heat slowly until intumescence ceases, and ignite in a muffle at a low red heat until a white ash is obtained. 3. — EXAMINATION OF ASH. Proceed as directed on page 106. 4. — DETECTION AND DETERMINATION OF COUMARIN AND VANILLIN.* Dealcoholize 50 grams of the extract in a glass evaporating dish upon a water bath at a temperature of about 80° C. ; add water from time to time to retain the original volume. After removal of the alcohol, add normal lead acetate solution, drop by drop, until no more precipitate forms. Stir with a glass rod to facilitate flocculation of the precipitate. Filter through a moistened filter; wash three times with a few cubic centimeters of hot water. Cool the filtrate and extract with ether by shaking out in a separatory funnel. Use 15 to 20 cc of ether at each separation and repeat the shaking out three or four times, or until a few drops of the ether evaporated upon a watch glass leaves no residue. Place the combined ether extracts containing all of the vanillin and coumarin in a clean separatory funnel and shake out repeatedly with from 5 to 10 cc of 7 per cent ammonia. b Repeat the treatment with ammonia once or twice after the fractions cease to be colored yellow. Set asr-idi' the combined ammoniacal solutions for the determination of vanillin. Wash the ether solution into an evaporating dish and allow the ether to evaporate at ordinary temperature. Extract the residue by treating it at room temperature with 5 to 10 cc of a petroleum fraction boiling between 30° and 40° C. ; allow it to stand several minutes and then decant into a dried, weighed evaporating dish. Repeat the extraction with petroleum ether until a drop evaporated on a watch glass leaves no residue. Allow the petroleum ether to evaporate at room temperature; dry in a dessicator over sulphuric acid and weigh as coumarin. The residue should be crystalline and have a melting point of 67° C. This, with the characteristic odor of coumarin, obtained by warming slightly, is sufficient for its identification. »Hess:m) Place a few drops of the oil obtained above in a Zeiss butyro-refractometer at a temperature of 30°. Normal oil when treated under these conditions will have a refraction of 67° to 72° and a dispersion of 2°. Limonene and most commercial adulterants give a higher reading, with the excep- tion of citronella aldehyde and oil of turpentine. !l 9. — DETECTION OF COLORING MATTERS. Follow directions given under coloring materials (p. 111*). For Arata's test (see page 112) the ' ' total residue ' ' may be used after the solution in water. Upon the addi- tion of hydrochloric acid in the determination of oil by precipitation, valuable indi- cations as to the color are frequently given. Tartrazin, napthol yellows, and curcuma retain their color, a pink or red coloration indicates a tropaeolin, while Martius' yellow and salts of di-nitrocresol are precipitated with decolorization of the extract. XIII.— FRUITS AND FRUIT PRODUCTS. By L. S. MUNSON and L. M. TOLMAN, Bureau of Chemistry, U. S. Department of Agriculture. 1. GENERAL DISCUSSION. In the examination of fruits and fruit products, much depends upon the object in view; and the preparation of samples, and the determinations made will depend largely upon the judgment of the analyst. For example, in the determination of heavy metals in canned fruits, one would not be justified in using the liquor, but should work on the pulped contents of the can, while for the detection of glucose, •Jour. Amor. Chein. Soc., 1899, 21, 1132. FRUITS AND FRUIT PRODUCTS. 75 preservatives, or coloring matter, examination of the liquor would be sufficient. The relative weights of liquor and fruit may be of value in detecting the presence of an excessive amount of water. A. S. Mitchell* has noted the presence of free sul- phuric acid in jellies. The methods for determination of mineral acids in vinegar can be readily applied to fruit products. The presence of phosphoric acid would be shown in the examination of the ash. The determination of solids by drying at 100° C. gives lower results than drying in vucuo at lower temperature, or calculation from the specific gravity of the solution, the reason undoubtedly being that levulose is dehydrated at 100° C.1' But as few laboratories are equipped to use the drying in vacno method, and as it is not possible to determine specific gravity in all cases, it is necessary to adopt some method which will give uniform results. In such a method the empirical rules have to be followed closely in order to obtain comparative results. 2. PREPARATION OF SAMPLE. (a) JUICES, JELLIES, AND SIRUPS. Prepare the fresh juices by pressing in a jelly bag the well pulped fruit and filter- ing through muslin. In the case of fresh fruit juices and fresh fruits the determina- tion of total and volatile acids and sugars, and the polarization should be made at once, as fermentation takes place in a very short time. Portions for polarization and reducing sugar may lie weighed out and an excess of lead sub-acetate added. They can then be kept for several days, if denied, without fermentation. All samples must be transferred without delay to glass-stoppered bottles and kept in a cool place. In the case of jellies, thoroughly mix to ensure uniformity in sampling. Weigh 60 grams into a 300-cc flask, dissolve in water by means of frequent shaking, make up to the mark with water, and use aliquot portions for the various determinations. With jellies that contain starch or other insoluble material, thoroughly mix before taking aliquot portions for the various determinations. 1 >ealcoholize sirups by evaporation to one-third their volume and dilute with water till they contain from 15 to 20 per cent of solids. (b) FUKSII nirns. Pulp the whole, well-cleaned fruit in a large nun-tar or by means of a food chopper and mix thoroughly. Incase of stone fruits remove the pits and determine their proportion in a weighed sample. (C) JAMS, MARMALADES, I'KKSKKYES, AND CANNED FRUITS. Thoroughly pulp the entire contents of the jar or can, as directed under fresh fruits; with stone fruits remove the pits, and if desired determine their proportion in a weighed sample. In the examination of canned fruits it is often sufficient to merely examine the sirups in which the fruits are preserved. In such cases the liquor may be separated and treated as is prescribed for juices. 3. — DETERMINATION OF TOTAL SOLIDS, (a) IN JUICES, JELLIES, AND SIRUPS. (1) By direct cfetmrnnotfon.— Measure 25 cc fl of a 20 percent solution [see 2 (a)] of jelly, or weigh 25 grams of juice, into a large flat-bottomed dish which contains •Coiiiiiiuniented hy letter. bCarr >md Sunburn, r. S. Dept. of \KT.. Division of Chemistry, llnl. 17. j>. i:il. •It'll pipette )>e used it must lie ^radiiMted so us to deliver M definite volume of a 20 per cent sugar solution lifter draining M delinite time. 76 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. about 4 or 5 grams of freshly ignited asbestos to absorb it; dry for from 20 to 24 hours in a water-jacketed oven. a If care is taken in measuring, this method will be found to be as accurate as weighing. In case of jellies that contain starch or insoluble matter, solids may be determined as directed below under (b) . (2) By calculation from specific gravity. — Determine the specific gravity of the solu- tion of jelly or diluted sirup, or of the juice, by means of a Westphal balance, picno- meter, or specific-gravity spindle, and calculate the solids from Table IV. b (b) IN FRESH FRUITS, JAMS, MARMALADES, PRESERVES, AND CANNED GOODS. Weigh about 20 grams of pulped fresh fruit, or such an amount of fruit products as will give not more than 3 to 4 grams of dried material, into a large flat-bottomed dish containing ignited asbestos; add a few cubic centimeters of water, mix thoroughly, and dry as in [(a) 1]. 4. — DETERMINATION OF INSOLUBLE SOLIDS. (a) KREMLA'S METHOD MODIFIED. Weigh 50 grams of the sample; transfer by the aid of warm water to a mortar and thoroughly macerate, c then transfer to a muslin filter and wash thoroughly with warm water, care being taken at each addition of water to thoroughly stir the pulp. Collect the filtrate in a 500-cc flask, cool and make up to volume. Usually this amount is sufficient to remove all soluble material. In extreme cases increase the washings to 1000 cc: transfer the insoluble residue to an evaporating dish, dry, and weigh. (b) GERMAN OFFICIAL METHOD. Transfer a weighed portion of the fruit product to a graduated flask, add water, shake thoroughly and make up to volume. Allow this to settle and either filter or decant off the supernatant liquid. Take an aliquot for the determination of soluble solids. Total solids less soluble solids equals insoluble solids. The fruit must be thoroughly macerated and the use of a mechanical shaker would be advisable. 5. — DETERMINATION OF ALCOHOL. Determine alcohol in 50 grams of the original material according to the method prescribed on page 82. 6. — DETERMINATION OF ASH. Evaporate to dryness 50 cc of the solution of jelly or diluted sirup [see 2 (a)], 25 grams of juice or fresh fruit, or 10 grams of jam, marmalade, preserves, or canned fruit in a large platinum dish; then thoroughly char at as low a heat as possible, extract with water, filter, and wash. Return the filter paper and insoluble material to the dish and thoroughly ignite; add the soluble portion and evaporate the whole to dry ness after add ing a few cubic centimeters of a solution of ammonium carbonate; then heat for a moment to very low redness; cool in a desiccator and weigh. The weighing must be made as quickly as possible, as the ash absorbs moisture very rapidly. » A. McGill, Laboratory of Internal Revenue, Ottawa, Canada, has devised a forced draft water oven for drying at temperatures between CO0 and 90° C. The oven is heated by means of ordinary gas burn- ers, and the temperature is controlled by introducing at the bottom of the oven a blast of air from a blower run by a small water motor. Before discharging into the oven the air tube enters the water chamber and is coiled a number of times in order to sufficiently warm the water before it enters the oven. The exit end of the air tube is covered with a concave-convex disc in order to distribute the blast and to prevent harmful currents. By regulating the burners and the flow of air a fairly con- stant temperature can be obtained. The bottom of the oven is curved instead of flat, to prevent bumping when the water is boiling; a perforated plate serves as a false bottom. »>Ztschr. Nahr. Hyg. Wtuir. 1892, 6, 483. c McGill, by letter, recommends the use of a mechanical shaker to obtain complete solution of the soluble material. FRUITS AND FRUIT PRODUCTS. 77 7. — EXAMINATION OF ASH. (a) ALKALINITY OF THE ASH. Into the platinum dish containing the ash run an excess of fifth-normal nitric acid and add a few drops of methyl orange. Carefully rub up the ash with a rubber tipped stirring rod and titrate the excess of acid with decinormal potassium hydroxid. Calculate the alkalinity to per cent of potassium carbonate in the original substance. One cubic centimeter of decinormal acid equals 0.00691 gram of potassium carbonate. (b) SULPHATES AND CHLORIDS. Wash the ash into a 50-cc flask and make up to the mark with water. In 25 cc of this solution determine the sulphates by precipitation with barium chlorid. The weight of barium sulphate times 0.7478 gives the weight of sulphates calculated as potassium sulphate. In the other portion of the solution determine the chlorids by the Volhard* method for chlorin. The nitric acid added before making the titration will, if it contain enough nitrous oxid, completely destroy the red color of the methyl orange and leave a clear solution for the titration. Calculate the chlorid as per cent of sodium chlorid. .Pure fruit jellies and jams give practically no chlorids or sulphates in this amount of ash, but glucose goods give appreciable amounts. If it is desired to make a complete ash analysis of juices or fresh fruits much larger amounts will have to be ashed. 8. — DETERMINATION OF TOTAL ACIDITY. Take 25 cc of the solution of jelly or diluted sirup [see 2 (a)], 10 grams of juice or fresh fruit, or 50 cc of the washings from the determination of insoluble solids, and dilute with recently boiled distilled water to about 250 cc, or less if the jelly be not highly colored; add phenolphthalein and titrate the acid with decinormal potassium hydroxid. In case of highly colored products litmus paper may be used instead of phenolphthalein. Calculate the results as sulphuric acid.b It is very desirable that acidity be so expressed as to allow of comparison. This end is not attained by expressing the acidity in terms of the dominant acid of the various fruits; hence H2S04 has been suggested, and already a number of laboratories have used this as a basis. 9. — DETERMINATION OF VOLATILE ACIDS. The determination of volatile acids in fruit products may be desirable in cases where fermentation or the use of decayed fruit is suspected. Dissolve 25 grams of sub- stance, dilute to 50 ce, and distill in a current of steam until about 200-cc have passed over. Titrate the distillate with decinormal potassium hydroxid and express the results as acetic acid. Each cubic centimeter of decinormal alkali is equivalent to 0.006 gram of acetic acid. 10. — DETECTION OF FREE MINERAL ACIDS. A. S. Mitchell and A. E. Leach have both called attention to the presence of free sulphuric and phosphoric acid in jellies. For method of detection see Hehner's method, page 64. 11. — DETERMINATION OF NITROGEN. Use*grams of jelly or other fruit product or 10 grams of juice or fresh fruit for the determination of nitrogen according to either the Gunning or the Kjeldahl method. Kxpivss results as protein (nitrogen multiplied by 6.25). •Ann. (1. Chcm. 1877, 190, 1. Sutton, Volumetric Analyses, eighth edition, p. 165. hSee Composition of Jellies and Jams. Tolman, Munson, and Bigelow. Jour. Am. Chem. Soc. 1901, 23, 348. 78 PEG VISIONAL METHODS FOR ANALYSIS OF FOODS. 12. — POLARIZATION. Dissolve half the normal weight of jelly or other fruit product, or the normal weight of juices or fresh fruits, in a sufficient quantity of water in a 100-cc sugar flask, add an excess of lead subacetate (from 5 to 10 cc, see footnote, p. 84), filter, and polarize in a 200-mm tube, observing the temperature of the solution. Invert 50 cc of this solution using 5 cc of hydrochloric acid and heating to 68° C. in 15 minutes. Polarize in a 220-mm tube at the same temperature as was employed in making the direct reading. On account of the large amounts of invert sugar usually found in these products it is necessary that the direct and invert readings should be made at the same tem- perature. 13. — DETERMINATION OF CANE SUGAR. (a) BY POLARIZATION. Calculate cane sugar from the direct and the invert readings according to Clerget's formula: g 100 (a -b) 144- 1 (b) BY INVERSION. Where only a small amount of cane sugar is present it is best determined by calcu- tion from the increase in reducing sugars after inversion. For this purpose treat 5 grams of jelly, sirup, or other fruit product, or 25 grams of juice or fresh fruit with lead subacetate in excess, and after making up to 100 cc and filtering invert 50 cc in a 100-cc flask with 5 cc of hydrochloric acid. After inversion neutralize the acid writh sodium hydroxid, precipitate excess of lead with sodium sulphate and increase in volume to 100 cc. Filter and dilute so that the solution does not contain more than 1 per cent of reducing sugar. The per cent increase in reducing sugar after inversion multiplied by 0.95 equals per cent of cane sugar. 14. — DETERMINATION OF REDUCING SUGARS. Treat 5 grams of jelly (25 cc of a 20 per cent solution [2 (a)] may be employed), sirup, or other fruit product, or 25 grams of juice or fresh fruit with lead subacetate in excess (2 to 5 cc); make up to 100 cc and filter. Transfer from 25 to 50 cc — depending upon the per cent of reducing sugar present — to a 100-cc flask and add a saturated solution of sodium sulphate in sufficient amount to precipitate the excess of lead; complete the volume to 100 cc and use the filtered solution for the determina- tion of reducing sugars. The approximate amount of reducing sugar present may be readily ascertained from the polarizations and from the percentage of solids. Use Allihn's method for the determination (p. 49). a 15. — DETERMINATION OF DEXTRIN. Dissolve 10 grams of the sample b in a 100-cc flask; add 20 mg of potassium fluorid and then about one-quarter of a cake of compressed yeast. c Allow the fermentation to proceed below 25° C. for 2 or 3 hours to prevent excessive foaming, and then place in an incubator at a temperature of from 27° to 30° C. for 5 days. At the end of that time, clarify with lead subactetate and alumina cream; make up to 100 cc and polarize in a 200-mm tube. A pure fruit jelly will show a rotation of not more than a few »U. S. Department of Agriculture, Division of Chemistry, Bulletin 46 revised, page 35. bln the case of jellies, 50 cc of a 20 per cent solution, prepared as directed under 1 (a), may be used. e Bigelow and McElroy. Jour. Am. Chem Soc. 1893, 16, 668. FRUITS AND FKUIT PRODUCTS. 79 tenths of a degree either to the right or to the left.a If a Schmidt and Hacnscli polariscope be used and a 10 per cent solution be polari/ed in a 200-mm tube, the number of degrees read on the sugar scale of the instrument multiplied by 0.8755 will give the percentage of dextrin, or the following formula1' may be used: 0X1,000 XV Percentage of dextrin = 19g ^ L x~^ in which C=degrees of circular rotation, V=volume in cubic centimeters of solution polarized, L= length of tube in centimeters, W= weight of sample in solution in grams. 16. — DETERMINATION OF ALCOHOL PRECIPITATE. Take 100 cc of a 20 per cent solution of jelly [see 2 (a)], diluted sirup, or of the washings from the determination of insoluble solids, and evaporate to 20 cc; then add slowly and with constant stirring 200 cc of 95 to 96 per cent alcohol and allow the mixture to stand overnight. Filter and wash with 80 per cent alcohol by volume. Wash this precipitate off the filter paper with hot water into a platinum dish; evap- orate to dry ness; dry at 100° C. for several hours and weigh; then burn off the organic matter and weigh the residue as ash. The loss in weight upon ignition is called alcohol precipitate. The ash should be largely lime and not more than 5 per cent of the total weight of the alcohol precipitate. If it is larger than this some of the salts of the organic acids have been brought down. Titrate the water-soluble portion of this ash with decinormal acid, as any potassium bitartrate precipitated by the alcohol can" thus be estimated. The general appearance of the alcohol precipitate is one of the best indications as to the presence of glucose and dextrin. Upon the addition of alcohol to a pure fruit product a flocculent precipitate is formed with no turbidity, while in the presence of glucose a white turbidity appears at once upon adding the alcohol, and a thick, gummy precipitate forms. 17. — DETERMINATION OF TARTARIC, CITRIC, AND MALIC ACIDS. c Use the filtrate from the alcohol precipitate in the determination of the organic acids. After evaporating off the alcohol and taking up the acids with water add lead subacetate until the solution is alkaline, then filter and wash the precipitate until only a slight amount of lead remains in the washings. Wash the precipitate off the filter paper into a beaker with hot water, precipitate the lead by hydrogen sulphid and filter off the lead sulphid while hot, washing with hot \vater. Evaporate the filtrate which contains the free organic acids to about 50 cc, neutralize exactly with potassium hydroxid, add an excess of strong solution of neutral calcium acetate with constant stirring, and allow to stand from 6 to 12 hours. Throw the precipitate of calcium tartrate on a filter paper and -wash until filtrate and washings make exactly 100 cc; ignite the filter paper and precipitate, and determine the lime and tartaric acid by titration. A correction of 0.0286 grams of tartaric acid, which is held in solution in the 100 cc of washings as calcium tartrate, must be added. Now evaporate the filtrate down to about 20 cc, and. if a precipitate of calcium citrate is formed tilter it off hot, wash with hot water, ignite, and titrate the lime. From » r. s. I )(-]>». of AKI-., Div. of Chem., Bui. 66. »• Wiley, Chem. News, issii, 4(>, 17.r>. cAiiMHlilirntion of Schmidt ^ Hu-pr's method. U.S. Dept. of Agr., Div.of Chem., Bui. 4« revised. p. 67; Ztschr. anal. Chem., 1882, 21, 634-641. 80 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. this calculate the citric acid. Again evaporate the filtrate to about 20 cc and add 3 volumes of 96 per cent alcohol by volume, which will throw down the calcium salt of tartaric acid held in solution, the rest of the citrate, and the malateand succinate. Filter this off, ignite, titrate,, and calculate as malic acid, after subtracting the tartaric acid present, as the amount of citric and succinic acid present is very small. 18. — DETERMINATION OP TARTARIC ACID. a To 100 cc of the fruit juice add 2 cc of glacial acetic acid, 2 or 3 drops of a 20 per cent potassium acetate solution and 15 grams of pure finely powdered potassium chlo- rid, dissolve this by shaking, and then add 20 cc of 96 per cent alcohol. Then stir vigorously for one minute, rubbing the walls of the beaker with the glass stirring rod to start the crystallization of the potassium bitartrate. Allow to stand 15 hours at room temperature. Filter and wash the precipitate onto a Gooch crucible with a thin asbestos felt, using the vacuum pump. Wash with a mixture of 15 grams of potassium chlorid, 20 cc alcohol, and 100 cc water. The beaker is rinsed three times with a few cubic centimeters of this solution. The precipitate is also washed with a few cubic centimeters, but so that not more than 20 cc in all of the wash solu- tion is used. The precipitate and asbestos filter are washed back into the beaker and heated to boiling. While still hot the solution is titrated with decinormal alkali, using phenolphthalein as indicator. To the amount of alkali used must be added 15 cc for the potassium bitartrate remaining dissolved in the solution. One cubic centimeter of decinormal alkali is equivalent to .0150 grams potassium bitartrate. 19. — DETERMINATION OF CITRIC Acm.b Fifty cubic centimeters of the fruit solution is evaporated on the water bath to a sirupy condition. To the residue add, very slowly at first, stirring constantly, 95 per cent alcohol until no further precipitate is formed; 70 to 80 cc are generally enough. Filter and wash the residue with 95 per cent alcohol. Evaporate the filtrate to elim- inate the alcohol, take up the residue with a little water and transfer to a graduated cylinder, making up to 10 cc. To 5 cc of this solution add half a cubic centimeter of glacial acetic acid, and to this add, drop by drop, a saturated solution of lead acetate. The presence of citric acid is shown by the appearance of a precipitate which pos- sesses the property of disappearing on being heated and reappearing on cooling. In order to separate the citric acicl from other acids, heat to boiling, filter, and wash with boiling water; then allow to cool and the precipitate of lead citrate will re-form. This lead precipitate may be filtered off, washed into weak alcohol, dried, weighed, and the citric acid calculated. It is necessary that there shall be no tartaric acid present. If the tartaric acid has been estimated, any error on this account may be avoided by adding enough decinormal potash to neutralize the tartaric acid before the alcohol is added. 20. — DETECTION OF PRESERVATIVES. Dissolve about 25 grams of the sample in water, acidify, and extract with ether. Remove the ether layer and allow it to evaporate spontaneously. Take up the residue, which may contain salicylic and benzpic acids and saccharin, with water. For detecting preservatives so senarated, and to test further for preservatives, use methods described by the referee on that subject (p. 107). 21. — DETECTION OF COLORING MATTER. Follow directions given on pages 111 and following. 22. — DETECTION OF ARTIFICIAL SWEETENING MATERIALS. Follow directions given on page 89. •Halenke & Moslingcr, Ztschr. anal. Chem., 1895, 34, 283. bMoslinger, Ztschr. Untcr. Nahr. u. Genuss., 1899, 2: 93. FERMENTED AND DISTILLED LIQUORS. 81 23. — DETECTION OF STARCH. First destroy the color of the jelly by treatment with sulphuric acid and potassium permanganate and then test with iodin. Bring the solution of jelly nearly to the point of boiling, add several cubic centimeters of dilute sulphuric acid and then potassium permanganate until all color is destroyed. By this treatment the starch remains unaffected. The test for starch is not necessarily an indication of its addition as an adulterant. It is almost always present in the apple, and occasionally in other fruity, and unless it is present in the jelly or other fruit product in considerable amounts it may be due to that source. 24. — DETECTION OF GELATIN. The presence of gelatin in jellies and jams is shown by a higher content of nitrogen. Precipitate a concentrated solution of jelly or jam with 10 volumes of absolute alcohol and determine nitrogen in dried precipitate by the Gunning method. a 25. — DETECTION OF AGAR AGAR." Cook the jelly with 5 per cent sulphuric acid, add a crystal of potassium perman- ganate and allow to settle. If agar is present the sediment will be rich in diatoms, which can be detected by use of microscope. 26. — THE DETERMINATION OF HEAVY MKTALS. Treat 100 grams of the preserve directly in a large porcelain evaporating dish with sufficient concentrated sulphuric acid to thoroughly carbonize the mass. If much water is present evaporate the material to a sirupy consistency before treating with the acid. From 15 to 25 cc of strong acid has been found sufficient to thoroughly carbonize the amount specified. Then ash the material, transfer the ash to a beaker of about 400-cc capacity, slightly acidify it with hydrochloric acid, and boil for a few moments. Methods for separation and determination of metals are given on page 52. XIV.-FERMENTED AND DISTILLED LIQUORS. By W. D. BIGELOW, In charge of Food Laboratory, Bureau of Chemistry, U. S. Department of Agriculture. (A) WINE. The determinations of most value in judging the purity of wine are alcohol, gly- cerol, extract, ash, total and volatile acids, and reducing sugar. The actual percent- age of these substances present is of interest, but much more important are certain relations between them, such as ash to extract, extract to alcohol, alcohol to glycerol, alcohol to acids, and volatile acids to total acids. Examination for preservatives and foreign coloring matter must also be made. Search is sometimes made for lead, which may result from cleansing bottles with the aid of shot; for copper and arsenic, which sometimes result from the use of insecticides and fungicides on the grapes; and for barium and strontium, which are sometimes used in southern Europe to remove the excess of sulphate introduced by plastering. A qualitative test is often made for nitrates to detect the addition of (impure) water, and for dextrin to determine whether glucose has been used in the preparation of the wine. Information regarding the manner of preparing the wine is often afforded by the determination of tannin, potassium sulphate (for plastered wines), and of phos- phoric acid. •A. Boemer, Chem. Ztg., 1895, 1», 552. *>C. Marpmann. Ztschr. f. angew. Mikrosk. 1896, 2, 260. Hi»-48— No. 65—02 6 82 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. For the various determinations, a measured volume can be taken more conveniently than a weighed quantity. The results can be calculated to per cent by weight by dividing the results expressed as grams per 100 cc by the specific gravity. 1. — DETERMINATION OF SPECIFIC GRAVITY. Determine specific gravity at the temperature of 15.6° C. by means of the pycnom- eter, small accurately graduated hydrometer, Westphal balance, or a Westphal plum- met on the analytical balance. The pycnometer, when used, should be heated quickly to room temperature after filling and before weighing, to prevent the error due to the collection of moisture on the outside. A small hole filed in the cap will permit the necessary expansion in the volume of liquid. 2. — DETERMINATION OF ALCOHOL. Measure 100 cc of the liquid into an Erlenmeyer flask of from 250 to 300-cc capacity ; add 50 cc of water; attach the flask to a vertical condenser by means of a bent tube and distill 100 cc. Foaming, which sometimes occurs, especially with new wines, may be prevented by the addition of a small amount of tannin. If it be desired to deter- mine alcohol in wines which have undergone acetic fermentation and contain a large amount of acetic acid, 0.1 or 0.2 gram of precipitated calcium carbonate should be added. This is unnecessary, however, in wines of normal taste and odor. Where only occasional determinations of alcohol are made it is found convenient to use an alembic Saleron. This apparatus is made of copper, and it can be readily taken apart and placed in a small box. No rubber connections are necessary, and the setting up requires but a few minutes. Determine the specific gravity of the distillate as directed under Specific Gravity, and obtain the corresponding percentage of alcohol, by vol- ume and grams per 100 cc, from Table II. 3. — DETERMINATION OF GLYCEROL. Evaporate 100 cc of winea in a porcelain dish on the water bath to a volume of about 10 cc and treat the residue with about 5 grams of fine sand and with from 1.5 to 2 cc of milk of lime (containing about 40 per cent of calcium hydroxid or 30 per cent of calcium oxid) for each gram of extract present, and evaporate almost to dry- ness. Treat the moist residue with 5 cc of 96 per cent alcohol (sp. gr. 0.81), remove the substance adhering to the sides of the dish with a spatula, and rub the whole mass to a paste, with the addition of a little more alcohol. Heat the mixture on the water bath, with constant stirring, to incipient boiling, and decant the liquid into a flask graduated at 100 and 110 cc. Wash the residue repeatedly by decantation with 10 cc portions of hot 96 per cent alcohol. Cool the contents of the flask to 15°, dilute to the 110-cc mark with 96 per cent alcohol, and filter through a folded filter. Evaporate 100 cc of the filtrate to a sirupy consistency in a porcelain dish, on a hot, but not boiling, water bath, transfer the residue to a small glass-stoppered graduated cylinder with 20 cc of absolute alcohol, and add three portions of 10 cc-each of absolute ether, mixing after each addition. Let stand until clear, then pour off through a filter, and wash the cylinder and filter with a mixture of one part absolute alcohol to one and one-half parts of absolute ether, pouring the wash liquor also through the filter. Evaporate the filtrate to a sirupy consistency, dry for one hour at the temperature of boiling water, weigh, ignite, and weigh again. The loss on ignition increased by one-tenth gives the glycerol expressed in grams per 100 cc. "With wines whose extract exceeds 5 grams per 100 cc, heat to boiling in a flask the portion to be used in the determination of glycerol, and treat with successive small portions of milk of lime until it becomes, first, darker, and then light in color. When cool, add 200 cc of 96 per cent alcohol (sp. gr. 0.8118), allow the precipitate to subside, filter, and wash with 96 per cent alcohol (sp. gr. 0.8118). Evaporate the filtrate to about 10 cc, add about 5 grams of sand and from 1.5 to 2 cc of milk of lime and proceed as directed above. FERMENTED AND DISTILLED LIQUORS. 83 4. — DETERMINATION OF EXTRACT. (a) FROM SPECIFIC GRAVITY OF DEALCOHOLIZED WINE. Preliminary to its exact determination, the extract should be calculated by the formula: in which sp is the specific gravity of the dealcoholized wine, x the specific gravity of the wine, .»y the specific gravity of the alcoholic distillate obtained in the estima- tion of alcohol. Illustration. — A sample of Catawba is examined with the result: Specific gravity of wine (#) ...................................... 1. 0402 Specific gravity of alcoholic distillate (:i-/) .......................... 9857 Difference (x— x/ ) ................................................ 0545 Specific gravity dealcoholized wine (1-f-a;— x'} ..................... 1 . 0545 Extract (from Table V) .......................... 14. 48 grams per 100 cc. The extract content equivalent to sp is obtained from table. (b) BY EVAPORATION. (1) In dry wines. (Having an extract content of less than 3 grams per 100 cc). Evaporate 50 cc of the sample on the water bath to a sirupy consistence in a flat- bottom platinum dish about 85 mm in diameter and capable of holding about 75 cc Heat the residue for two and a halt' hours in a drying oven at the temperature of boiling water and weigh. This weight multiplied by 2 gives grams of total residue in 100 cc. The sugar-free extract is found by deducting the weight of sugar in excess of 0.1 gram per 100 cc from the total residue. In the case of plastered wines, the potassium sulphate in excess of 0. 1 gram is also deducted. (2) In sweet wines. When the extract content is between 3 and 6 grams per 100 cc treat 25 cc of the sample as described under dry wines. When the extract exceeds 6 grams per 100 cc, however, the result obtained under (a) is accepted, and it is not attempted to deter- mine it gravimetrically. This is because of the serious error connected with drying levulose at high temperature. The table referred to here was obtained by drying at 75° C. in vacuo. 5. — DETERMINATION OF ASM. Ignite at low redness, until thoroughly charred, the residue from the determina- tion of extract,* exhaust with water, filter, and wash. Return the filter paper and insoluble material to the dish and burn to a white ash, add the soluble portion and evaporate the whole to dryness, heat to a low redness, cool in a desiccator, and weigh. With dry wines complete combustion can often be obtained without leaching. 6. — DETERMINATION OF TOTAL ACIDS. Expel any carbon dioxid that is present by continued shaking. Transfer 25 cc of the sample to a beaker, heat to incipient boiling, and, in the case of white wines, add about 10 drops of a neutral litmus solution and titrate while still hot with decinormal sodium hydroxid solution. With red wines, add dirinorinal sodium hydroxid solution until the red color changes to violet, and continue adding a few drops at a time until a drop of the mixture placed on delicate neutral litmus paper ceases to show an acid reaction.15 The result is expressed in terms of tartaric acid. •Employ the residue obtained by evaporating 25 co of the \\inc -when tin- extract lias beencalcu- ItUfil from specific gravity. bSei; Appendix, p. 1 >•>. 84 PROVISIONAL METHODS JOB ANALYSIS OF FOODS. One cubic centimeter of decinormal sodium hydroxid solution is equivalent to 0.0075 gram tartaric acid. 7. — DETERMINATION OF VOLATILE ACIDS. Distill, in a current of steam, 50 cc of wine, to which a little tannin has been added to prevent foaming. Heat the flask containing the sample until the liquid boils, lower the flame under it and pass the steam through until 200 cc have been collected in the receiver; titrate the distillate with decinormal sodium hydroxid solutic-n, using phenolphthalein as indicator, and express the result as acetic acid. One cubic centimeter of decinormal sodium hydroxid solution is equivalent to 0.006 gram acetic acid. 8. — DETERMINATION OP FIXED ACIDS. The amount of fixed acids is ascertained by subtracting 1.25 times the volatile acids from the total acids expressed as tartaric. 9. — DETERMINATION OF UNDETERMINED EXTRACT. The amount of undetermined extract is ascertained by subtracting the sum of the glycerol, ash, protein, and fixed acids from the weight of the sugar-free extract. 10. — DETERMINATION OF SUGAR.* (a) PREPARATION OF SOLUTION. Place 200 cc of wine in a porcelain dish, exactly neutralize with an approxi- mately normal solution of sodium hydroxid, using litmus paper as indicator, and evaporate to about one-fourth the original volume. Transfer to a 200-cc flask, add sufficient basic lead acetateb to clarify, dilute to the mark with water, shake, and filter through a ribbed filter. Transfer 100 cc of the filtrate to a flask graduated at 100 and 110 cc, fill to the upper mark with a saturated solution of sodium sulphate, shake and filter. (b) POLARIZATION. (1) Direct. Polarize part of the filtrate in a 200-mm tube, in a Schmidt and Haensch polari- scope, and increase the reading by one-tenth for the polariscope reading. In case the reading is taken on some other instrument than the Schmidt and Haensch it may be calculated by the following data: 1° Ventzke =0.3468° angular rotation D. 1° angular rotation D =2.8835° Ventzke. 1° Ventzke =2.6048° Wild (sugar scale). 1° Wild (sugar scale) =0.3840° Ventzke. 1° Wild (sugar scale) =0.1331° angular rotation D. 1 ° angular rotation D =0.7511° Wild (sugar scale) . 1° Laurent (sugar scale) =0.2167° angular rotation D. 1° angular rotation D =4.6154° Laurent (sugar scale). (2) Invert. In order to determine the presence or absence of sucrose it is necessary to subject the sugars to inversion. The filtrate from the lead sulphate obtained in (a) may be 'See Appendix, p. 156. b Prepared by boiling for half an hour 430 grains of normal lead acetate, 130 grams of litharge, and. 1000 cc of water. The mixture is allowed to cool and settle, when the supernatant liquid is diluted to 1.25 specific gravity with recently boiled water FERMENTED AND DISTILLED LIQUORS. 85 conveniently employed for this purpose. Fill a flask graduated at 50 and 55 cc to the 50-cc mark with the filtrate, add 5 cc of concentrated hydrochloric acid, invert; polarize in a 220-mrn tube, and increase the reading one-tenth to allow for dilution. (3) After fermentat ion . In the case of wines polarizing between +2.3° and +0.9° the use of glucose in their preparation can be proved or disproved after fermentation by the presence or absence of certain unfermentable constituents. Dealcoholize 200 cc of wine by evaporating to about one-fourth its volume, and add enough water to the residue to make its sugar content less than 15 per cent. For the purpose of this operation the sugar content of the wine may be assumed to be 2 per cent less than the extract. Add 2 or 3 grams of compressed yeast, let stand at about 25° C. for four or five days, when fermentation will be complete. Evaporate the fermented liquid in a porcelain dish to a thin sirup after the addi- tion of a little sand and a few drops of a 20 per cent solution of potassium acetate. To the residue add 200 cc of 90 per cent alcohol with constant stirring. Separate the alcoholic solution by filtration and evaporate until about 5 cc remain. Mix the residue with washed boneblack, filter into a graduated cylinder, and wash until the filtrate (cooled to 15° C. ) amounts to 30 cc. When the filtrate shows a dextrorota- tion of more than 1.5° it indicates the presence of the unfermentable constituents of commercial glucose. Results by this method are not reliable with wines that are heavily preserved. (c) REDUCING SUGARS. Dilute a portion of the solution prepared as directed under (a) until it does not contain more than 1 per ceftt of sugar. In making this dilution the sugar-free extract of a wine may be taken as 2 per cent. The number of volumes of water to be added to the filtrate is thus determined by deducting 2 from the total extract. If the wine is not to be polarized, or for any reason a separate portion is to be pre- pared for the reduction, the dilution may be conveniently made prior to the clarifi- cation. Use Allihn's method, expressing the results as dextrose (see p. 49). (d) CANE SUGAR. ( 1 ) By reduction. Invert a portion of the filtrate obtained in (a) as directed under (b) (2) ; determine reducing sugars according to (c) ; deduct from the figure thus obtained the reducing sugars originally present, and multiply the result by 0.95 for conversion into cane sugar. (2) By polarization. Calculate from the direct and invert polarizations by the Clerget formula: Per cent sucrose 144- -£ (e) COMMERCIAL GLUCOSE.* (1) Wine with not more than 0.1 per cent of reducing sugar, and which polarizes to the left or not more than 0.9° to the right, has not been treated with glucose. (2) Wine with not more than 0.1 per cent of reducing sugar, and which polarizes 0.9° or more to the right, may contain dextrin and the unfermentable constituents of commercial glucose. In such a case, examine according to 10 (3) and 11. (3) If the reducing sugar exceeds 0.1 per cent, examine according to 10 (3) for the unfermentable constituents of commercial glucose. • Borgmann, Analyse des Weines, 2d ed., p. 77. 86 PROVISIONAL METHODS FOB ANALYSIS OF FOODS. 11. — DETERMINATION OF GUM AND DEXTRIN. Evaporate 100 cc of wine to about 10 cc and add 10 cc of 96 per cent alcohol (sp. gr. 0.81). If gum or dextrin be present (indicated by the formation of a voluminous precipitate) , continue the addition of alcohol slowly and with stirring until 100 cc have been added. Let stand over night, filter, and wash with 80 per cent alcohol by volume (sp. gr. 0.84). The precipitate may then be dried and weighed, or it may be treated according to Sachsse's method for the determination of starch. 12. — DETERMINATION OF TANNIN AND COLORING MATTER. a Dealcoholize 100 cc by evaporation and dilute with water to the original volume. Transfer 10 cc to a porcelain dish of about 2 liters capacity; add about a liter of water and exactly 20 cc of indigo11 solution, measuring the latter by means of a burette. Add decinormal potassium permanganate solution, which has been stand- ardized against decinormal oxalic acid, a cubic centimeter at a time, until the blue color changes to green; then a few drops at a time until the color becomes bright yellow. Designate the number of cubic centimeters of permanganate solution employed by (a). Treat 10 cc of the dealcoholized wine, prepared as above, with carefully purified boneblack for fifteen minutes; filter and wash the boneblack thoroughly with water. Add a liter of water and 20 cc of indigo solution and titrate with perman- ganate as above. Designate the number of cubic centimeters of permanganate solution employed by (b). Then a — b = c = the number of cubic centimeters of permanganate solution required for the oxidation of the tannin and coloring matter in 10 cc of wine. Multiply (c) (corrected to cubic centimeters of decinormal solution, if the solution employed is not exactly decinormal) by 0.04157 for tannin and coloring matter, expressed in grams per 100 cc. One cubic centimeter of decinormal permanganate solution is equivalent to 0.004157 gram tannin. 13. — DETERMINATION OF SODIUM CHLORID. Sodium chlorid is obtained by dissolving the ash in water, slightly acidifying with nitric acid, neutralizing with calcium carbonate, and titrating with silver nitrate, using normal potassium chromate as indicator. 14. — DETERMINATION OF POTASSIUM SULPHATE. Precipitate sulphuric acid directly in 50 cc of wine by means of barium chlorid, and determine the resulting barium sulphate by the ordinary method. Express the result in grams of potassium sulphate per 100 cc. In all cases this determination should be made in the original wine, as results obtained with the ash are always low. 15. — DETERMINATION OF PHOSPHORIC ACID. Determine phosphoric acid in the ash by the official volumetric method. In case the ash has been used for other determinations, and it is necessary to begin with the original wine, evaporate 100 cc of dry wines and ignite directly. With sweet wines, evaporate 100 cc to a sirupy consistency in a flask of about 250-cc capacity, add 25 cc of concentrated sulphuric acid and heat with a low flame till the evolution of g;as "Neubauer-Lowenthal method. Annalen der Oenologie, 2, 1. b Instead of the indigo-carmin called for by the original method, sodium sulphindigotate maybe employed, as suggested by Schroeder (Ztfcchr. anal. Chem., 1886, 25, 112). To prepare the solution, dissolve 6 grams of sodium stilphindigotate m 500 cc of water with aid of heat; cool; add 50 cc of con- centrated sulphuric acid; dilute to 1 liter and filter. (U. S. Dept. of Agr., Bui. 46 revised, p. 66.) FERMENTED AND DISTILLED LIQUORS. 87 ceases. Add about 75 cc concentrated nitric acid, warm gently, and finally evaporate almost to dryness. Then add 10 cc of concentrated sulphuric acid and a little mer- cury and boil till the solution clears. a Employ the official volumetric method for phosphoric acid, as stated above. 16. — DETERMINATION OF TARTARIC ACID AND TARTRATES. (a) TOTAL TARTARIC ACID.b To 100 cc of wine add 2 cc of glacial acetic acid, 3 drops of a 20 per cent solution of potassium acetate, and 15 grams of powdered potassium chlorid, and stir to hasten solution. Add 15 cc of 95 percent alcohol (sp. gr. 0.81) and rub the side of the beaker vigorously with a glass rod for about 1 minute to start crystallization. Let stand at least 15 hours at room temperature; decant the liquid from the separated acid potassium tartrate as rapidly as possible (using vacuum) through a Gooch cru- cible prepared with a very thin film of asbestos, transferring no more of the precipi- tate to the crucible than necessary. Wash the precipitate and filter three times with a small amount of a mixture of 15 grams potassium chlorid, 20 cc of 95 per cent alco- hol (sp. gr. 0.81), and 100 cc water, using not more than 20 cc of the 'wash solution in all. Transfer the asbestos film and precipitate to the beaker in which the precipi- tation took place, wa«h out the Gooch crucible with hot water, add about 50 cc of hot water, heat to boiling, and titrate the hot solution with decinormal sodium hydroxid, using delicate litmus tincture or litmus paper as indicator. Increase the number of cubic centimeters of decinormal alkali employed by 1.5 on account of the solubility of the precipitate. This figure multiplied by 0.015 gives the amount of total tartaric acid in grams per 100 cc. (b) CREAM OF TARTAR. Ignite the residue obtained from the evaporation of 50 cc of wine as directed under the determination of ash. Exhaust the ash with hot water, add to the filtrate 25 cc of decinormal hydrochloric acid, heat to incipient boiling and titrate with decinor- mal alkali solution, using litmus as indicator. Deduct from 25 cc the number of cubic centimeters of decinormal alkali employed and multiply the remainder by 0.0188 for potassium bitartrate expressed in grams. (C) FREE TARTARIC ACID. Add 25 cc of decinormal hydrochloric acid to the ash of 50 cc of wine, heat to incipient boiling and titrate with decinormal sodium hydroxid, using litmus as indi- cator. Deduct the number of cubic centimeters of alkali employed from 25 and multiply the remainder by 0.0075 to obtain the amount of tartaric acid necessary to combine with all the ash (considering it to consist entirely of potash). Deduct the figure so obtained from the total tartaric acid for the free tartaric acid. 17. — DETERMINATION OF PROTEIN. Determine nitrogen in 50 cc of wine by the Kjeldahl or the Gunning method, and multiply the result so obtained by 6.25. 18. — DETERMINATION OF HEAVY METALS. Lead is often found in wine as a result of the use of shot in cleaning bottles, and copper and arsenic may occur in wine made from grapes sprayed with insecticides. Lea. '• Halt-tike mid Mosliiitfcr, Ztschr. anal, Clu-in.. l.v.tfi, 84, 263. 88 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. Arsenic may be detected or determined by the Marsh apparatus if combustion be effected by the method given under the determination of phosphoric acid (p. 86). Copper may be precipitated electrolytically a in 500 cc of the undiluted wine by using as electrodes pieces of platinum foil 3 by 15 cm. 19. — DETERMINATION OF BARIUM AND STRONTIUM. b Evaporate to dryness 100 cc of wine, incinerate as directed under the determina- tion of ash (p. 83), dissolve in dilute hydrochloric acid, evaporate to dryness, and examine the residue spectroscopically. If barium or strontium be present, fuse with sodium carbonate0 to decompose silicates, dissolve in water and determine by precipitation with sulphuric acid. 20. — DETECTION OF FOREIGN COLORING MATTER. Follow directions given under Coloring Matter (pp. Ill and following). 21. — DETECTION OF NITRATES. (a) WHITE WINE. Treat a few drops of the wine in a porcelain dish with 2 or 3 cc of concentrated sulphuric acid which contains about 0.1 gram of diphenylamind per 100 cc. The deep blue color formed in the presence of nitrates appears so quickly that it is not obscured, even in sweet wine, by the blackening produced by the action of sulphuric acid on the sugur. (b) RED WINE. Clarify with basic lead acetate and remove the excess of lead with sodium sulphate, as directed under the determination of sugar (p. 84). Filter, and treat a few drops of the filtrate as directed under (a). 22. — DETECTION OF PRESERVATIVES. The preservatives to be tested for in wines are salicylic acid, benzoic acid, saccharin, abrastol, hydronaphthol, boric acid, borofluorids, and silicofluorids. Of these the salicylic and benzoic acids are both somewhat commonly employed. Abrastol is said to be used to some extent in Europe, but has not yet been reported in American wines. Hydronaphthol has been used in rare instances, and is still used with suffi- cient frequency to warrant more consideration than it usually receives from food laboratories. Boric acid is better known as a preservative for milk and meat prepara- tions than for fruit and fruit preparations. It is sometimes used, however, in both wine and beer. Its detection is a somewhat more complicated matter than is the case with the other preservatives, because a small amount of boric acid is normal to wines. It is sometimes a difficult matter to fix the amount which may naturally occur. In order to make this test of practical value, therefore, it is essential that the determination of boric acid should be quantitative. The alkaline fluorids, as well as the alkaline borofluorids and silicofluorids, are coming into somewhat general use now as food preservatives, although they have not been frequently reported in wines. •Fruhauf and Ursic, Bericht u. die Versammlung Oesterreichischer Oenomiker in Bozen, 1886, p. 66; Borgmann, Anal, des Weines, 2d ed., p. 146. bBorgmann, Anal, des Weinea, 2d ed., p. 143. «R. Fresenius, Ztschr. anal. Chem., 1890, 29, 20, 143 and 413; 1891, 30, 18, 452 and 583; 1893, 32, 189 and 312. •JEgger, Arch. Hyg., 2, 373. FERMENTED AND DISTILLED LIQUORS. 89 (a) SALICYLIC ACID. Treat about 75 cc of wine with sufficient basic lead acetate a to clarify, and filter through a ribbed filter paper. Add from 5 to 10 cc of dilute sulphuric acid ( 1-3) , allow the precipitated lead sulphate to subside, and decant about 50 cc of the supernatant liquid into a separatory funnel. Extract with ether or chloroform and test for salicylic acid as directed under Food preservatives (p. 108). The writer has obtained much more satisfactory results by extracting after clarification as directed above, than by extracting the wine directly with a mixture of ether and petroleum ether, or by extracting the evaporated residue from the ether extract with petroleum ether. In no case should the volume of wine extracted for the detection of salicylic acid greatly exceed 50 cc. A similar reaction (with ferric chlorid) is said to be obtained sometimes from wines which contain no salicylic acid when a large volume of the wine is employed. b (b) BENZOIC ACID. Acidify about 100 cc of wine with dilute (1-3) sulphuric acid, extract with ether and detect by Mohler's method, as described under Food preservatives (p. 109). The presence of benzoic acid may be confirmed by neutralizing the aqueous solu- tion of the extracted benzoic acid with sodium hydroxid, evaporating to a very small volume, and acidifying with sulphuric acid, when the presence of a large amount of benzoic acid is indicated by the formation of a white flocculent precipitate. The concentrated polution of the sodium salt may be further tested by adding a few drops of phenolphthalein solution, and then a very dilute solution of sodium hydroxid drop by drop, till an alkaline reaction is obtained, and a drop of a 0.5 per cent ferric chlorid solution, which should decolorize the phenolphthalein, when ferric benzoate is precipitated. The appearance of ferric benzoate is markedly different from that of ferric hydroxid, in that it is almost white when viewed by transmitted light and brown by reflected light, whereas ferric hydroxid has a brown color in both cases. (c) DETECTION OF SACCHARIN. Proceed as directed on page 109. (d) SUCROL OR DULCIN. (1) Morpurgo's method.0 Evaporate about 100 cc of wine to a sirupy consistency after the addition of about 5 grams of lead carbonate, and extract the residue several times with alcohol of about 90 per cent; evaporate the alcoholic extract to dry ness; extract the residue with ether, and allow the ether to evaporate spontaneously in a porcelain dish. Now add 2 or 3 drops each of phenol and concentrated sulphuric acid and heat for about five minutes on the water bath; cool; transfer to a test tube and pour ammo- nia or sodium hydroxid over the surface with the least possible mixing. The presence of dulcin is indicated by the formation of a blue zone at the plane of contact. (2) Jorisson's method.* Suspend the residue from the ether extract obtained as directed above in about 5 cc of water; add from 2 to 4 cc of an approximately 10 per cent solution of mercuric nitrate, and heat from 5 to 10 minutes on the water bath. In the presence of sucrol, a violet blue color is formed, which is changed to a deep violet by the addition of lead peroxid. •See footnote on page 84. Xi-chr. anal. Chem., 18%, «*">, 104. *>Medicus, Ztschr. anal. Chem., 1896, 85, 398. *Ib., G2«. 90 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. (e) DETERMINATION OF TOTAL SULPHUROUS ACID. Distill 100 cc of wine in a current of carbon dioxid, after the addition of about 5 cc of a 20 per cent solution of glacial phosphoric acid, until 50 cc have passed over. Collect the distillate in a decinorinal iodin solution in a flask closed with a stopper perforated with two holes, through one of which the end of the condenser passes and through the other a U-tube containing a portion of the standardized iodin solu- tion. Twenty-five cc of decinormal iodin solution may be employed, diluted with water to give the desired volume. The method and apparatus may be simplified without material loss in accuracy by omitting the current of carbon dioxid, adding 10 cc of phosphoric acid instead of 5 cc, and dropping into the distilling flask a piece of sodium bicarbonate weighing not more than a gram immediately before attaching to the condenser. The carbon dioxid liberated is not sufficient to expel the air entirely from the apparatus, but will prevent oxidation to a large extent. The U-tube trap may also be omitted if the end of the condenser tube be made to extend below the surface of the iodin solution, and the distillation conducted with a steady flame. When the distillation is finished, wash the contents of the U-tube into the flask and determine the excess of iodin with standardized thiosulphate solution. On account of its lack of permanence, the iodin solution employed should be titrated from time to time with a decinormal thiosulphate solution (containing 24.8 grams Na2S2O3.5 H2O per liter). The number of cubic centimeters of decinormal iodin solution employed, less the number of cubic centimeters of thiosulphate solution required at the end of the determination, is multiplied by 0.0032 for the grains of sulphur dioxid per 100 cc of wine. Fairly accurate results may also be obtained by the following method: Place 25 cc of a solution of potassium hydroxid containing 56 grams per liter in a flask of approximately 200-cc capacity. Introduce 50 cc of wine by means of a pipette, mix with the potassium hydroxid, and allow the mixture to stand for fifteen minutes with occasional agitation. Add 10 cc of 1-3 sulphuric acid and a few cubic centimeters of starch solution, and titrate the mixture with a N/50 iodin solution. Introduce the iodin solution as rapidly as possible and continue the addition until the blue color will last for several minutes. One cubic centimeter of N/50 iodin solution is equivalent to 0.00064 gram of sulphur dioxid. The number of cubic centimeters of the iodin solution employed, multiplied by 0.00128, gives the weight of the total sulphur dioxid expressed in grams per 100 cc. (f) DETERMINATION OF FREE SULPHUROUS ACID. Treat 50 cc of wine in a flask, having a capacity of approximately 200 cc, with about 5 cc of 1-3 sulphuric acid, add a small piece of sodium carbonate (about 0.5 gram) to expel the air, and titrate the sulphurous acid with N/50 iodin solution, as directed under total sulphurous acid. One cubic centimeter of N/50 iodin solution is equivalent to 0.00064 gram of sul- phur dioxid. The number of cubic centimeters of iodin solution employed, multiplied by 0.00128, gives the weight of the free sulphurous acid expressed as sulphur dioxid in grams per 100 cc. (g) DETECTION OF BETA-NAPHTHOL. Extract 200 cc of wine with 10 cc of chloroform in a separatory funnel, add a few drops of alcoholic potash to the chloroform extract in a test tube, and place in a boiling water bath for two minutes. The presence of beta-naphthol is indicated by the formation of a deep blue color, which changes through green to yellow. FERMENTED AND DISTILLED LIQUORS. 91 (h) DETECTION OF ABRASTOL. (1) Sinabaldi's method.* Make 50 cc of the sample alkaline with a few drops of ammonia and extract with 10 cc of amyl alcohol (ethyl alcohol is added if an emulsion be formed). Decant the amyl alcohol, filter if turbid, and evaporate to dryness. Add to the residue 2 cc of a mixture of equal parts of strong nitric acid and water, heat on the water bath until half of the water is evaporated, and transfer to a test tube with the addition of 1 cc of water. Add about 0.2 gram of ferrous sulphate and an excess of ammonia, drop by drop, with constant shaking. If the resultant precipitate be of a reddish color, dissolve it in a few drops of sulphuric acid, and add ferrous sulphate and ammonia as before. As soon as a dark-colored or greenish precipitate has been obtained, introduce 5 cc of alcohol, dissolve the precipitate in sulphuric acid, and shake the fluid well and filter. In the absence of abrastol this method gives a color- less or light-yellow liquid, while a red color is produced in the presence of 0.01 gram of abrastol. (2) Sangte-Ferr£reb method. Boil 200 cc of wine with 8 cc of concentrated hydrochloric acid for one hour in a flask with reflux condenser attached. Abrastol is thus converted into beta-naphthol and is detected as directed under (g) . (i) BORIC ACID. Boric acid is a normal constituent of wine and its qualitative detection in wine is therefore of little value unless a very heavy reaction is obtained. For methods of detection and estimation, see page 110. (j) DETECTION OF FLUORIDS. (1) Firxt method.0 Heat to boiling about 100 grams of wine, made slightly alkaline with ammonium carbonate and precipitate the fluorin with 2 or 3 cc of an approximately 10 per cent solution of calcium chlorid. Continue the boiling for five minutes, separ- ate the precipitate by filtration, wash with a little water, dry, and ignite in a platinum crucible. Add 1 cc of strong sulphuric acid, cover the crucible with a watch glass coated with paraffin or wax, with a character marked through the wax so as to permit the watch glass to be etched at some point, and heat on a water bath for an hour at a temperature of from 75° to 80° C. One milligram can be readily detected by this method. The delicacy of the method is impaired by the presence of a small amount of silica in the ash of the wine. (2) Second method. If it is desired, the preceding method may be varied by mixing a small amount of precipitated silica with the precipitated calcium fluorid and placing it in a crucible covered by a watch glass which is not coated with paraffin, and to which a drop of water is suspended on the underside. Add 1 cc of concentrated sulphuric acid to the crucible, and heat for an hour at the temperature of 70° or 80° C. The silicon fluorid which is formed is decomposed by the water, leaving a gelatinous deposit of silica, while a ring is frequently etched at the circumference of the drop of water. Any fluosilicates and llnoborates present will also be indicated by this reaction. » MOD. Sri.. 1M»:', [ I] . 7, M-J. o Neviere and Hubert, Mon. Sci., 1895 [A], 9, 324. 1 cunil>. ivmi. i.v.i:;. 1 17, y:5. 92 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. (k) DETECTION OF FLUOBORATES AND FLUOSILICATES. Make about 200 cc of wine alkaline with limewTater, evaporate to dryness, and incinerate. Extract the crude ash first obtained with water, to which sufficient acetic acid has been added to decompose carbonates, filter, burn the insoluble por- tion, extract with dilute acetic acid, and again filter. The insoluble portion now contains calcium silicate and fluorid, while the filtrate will contain all the boric acid present. (1) First method.* Incinerate the filter containing the insoluble portion, mix with a little precipitated silica, and place, with the addition of 1 or 2 cc of concentrated sulphuric acid, in a short test tube which is attached to a small U-tube containing a few drops of water. The test tube is now placed in a beaker of water, which is kept hot on the steam bath for from 30 to 40 minutes. If any fluorid be present the silicon fluorid gener- ated will be decomposed by the water in the U-tube and will form a gelatinous deposit on the walls of the tube. The filtrate is now tested as directed under boric acid. If both hydrofluoric and boric acids be present, it is probable that they were combined as borofluorid. If, however, silicon fluorid be detected and not boric acid, the operation is repeated without the introduction of the silica, in which case the formation of the silicon skeleton is conclusive of the presence of fluosilicate.b (2) Second method. Incinerate the filter containing the insoluble portion in a platinum crucible, mix with a little precipitated silica, and add 1 cc of concentrated sulphuric acid. Cover the crucible with a watch glass to whose underside a drop of water is suspended, and heat an hour at the temperature of 70° or 80° C. The silicon fluorid which is formed is decomposed by the water, leaving a gelatinous deposit of silica. Test the filtrate for boric acid as described above. (B) BEER. 1. — PREPARATION OF SAMPLE. Transfer the contents of bottle or bottles into a large flask and shake vigorously to hasten the escape of carbon dioxid. The beer may then be poured into a second receptacle from under the foam. 2. — DETERMINATION OF SPECIFIC GRAVITY. Follow the directions given for the determination of specific gravity in wine (p. 82). 3. — DETERMINATION OF ALCOHOL. Follow the directions given for the determination of alcohol in wine (p 82). 4. — DETERMINATION OF EXTRACT. Ascertain the extract content corresponding to the specific gravity of the dealco- holized beer according to Table III. For this purpose employ the formula: sp=g+(l— a) 'Neviere and Hubert, Mon. Sci., 1895 [/>], 9, :W4. b It mast be remembered that in an ash that contains an appreciable amount of silica, sulphuric acid will liberate silicon fluorid rather than hydrofluoric acid. The presence of a fluosilicate is indicated, therefore, and not of a fluorid. FERMENTED AND DISTILLED LIQUORS. 93 in which sp is the specific gravity of the dealcoholized beer, g the specific gravity of the beer, and a the specific gravity of the distillate obtained in the determination of alcohol. In place of this formula, the residue from the distillation of alcohol is sometimes diluted to the original volume, and its specific gravity taken. This is often impracticable owing to the necessity of employing tannin to prevent foaming in the distilling flask, and owing to the coagulation of proteids during the distillation. The extract of beer can not be accurately determined by evaporation and drying at the boiling point of water because of the dehydration of the maltose. 5. — DETERMINATION OF ORIGINAL GRAVITY OF WORT. The various methods employed to obtain this figure depend on the fact that the sugars yield about half their weight of alcohol when fermented. Employ the formula: G=sp+si in which G is the specific gravity of the original wort, sp the specific gravity of the dealcoholized beer (see 4), and si the amount of saccharine matter destroyed by fermentation — obtained from the following table: Saccharine matter lost by fermentation. * 1— a 0 1 2 3 4 5 6 7 8 9 0.000 0.0003 0.0006 0.0009 0. 0012 0.0015 0.0018 0.0021 0.0024 0.0027 .001 0.0030 .0033 .0037 .0041 .0044 .0048 .0051 .0055 .0059 .0062 .002 .0066 .0070 .0074 .0078 .0082 .0086 .0090 .0094 .0098 .0102 .003 .0107 .0111 .0115 .0120 .0124 .0129 .0133 .0138 .0142 .0147 .004 .0151 .0155 .0160 .0164 .0168 .0173 .0177 .0182 .0186 .0191 .005 .0195 .0199 .0204 .0209 .0213 .0218 .0222 .0227 .0231 .0236 .006 .0241 .0245 .0250 .0255 .0260 .0264 .0269 .0274 .0278 .0283 .007 .0288 .0292 .0297 .0302 .0307 .0312 .0317 .0322 .0327 .0332 .008 .0337 .0343 .0348 .0354 .0359 .0365 .0370 .0375 .0380 .0386 .009 .0391 . 0397 .0402 .0407 .0412 .0417 .0422 .0427 .0432 .0437 .010 .0442 .0447 .0451 .0456 .0460 .0465 .0476 .0475 .0480 .0485 .011 .0490 .0496 .0501 .0506 .0512 .0517 .0522 .0527 .0533 .0538 .012 .0543 .0549 .0554 .0559 .0564 .0569 .0574 .0579 .0584 .0589 .013 .0594 .0600 .0605 .0611 .0616 .0622 .0627 .0633 .0638 .0643 .014 .0648 .0654 .0659 .0665 .0671 .0676 .0682 .0687 .0693 .0699 .015 .0705 .0711 .0717 . 0723 .0729 .0735 .0741 .0747 .0753 .0759 In this table, 1 — a is found by deducting from 1.0 the specific gravity of the alcohol distillate obtained in the determination of alcohol. In case of beer of high acidity, it must be increased by the value of 6 in the formula &= 0.9* -0.14, in which I is the percentage of acid calculated to lactic acid. The figure 0.14 is taken as the alcoholic equivalent of the average acid content of beer (ordinarily about 0.15 percent lactic acid), and is deducted for that reason. The table here given is that of Graham, Hofmann, and Redwood, b except that it is expressed here as •Alien, Com. Org. Anal., Vol. I. b Report on Original Gravities, 1852; Allen, Commercial Organic Analysis, 3d edition, Vol. I, p. 136. 94 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. specific gravity instead of parts per thousand. It has been adopted by the English excise. The metho.d outlined above was employed by the same authors, except that they determined the specific gravity of the dealcoholized beer, directly on the residue from the alcohol determination after diluting to the volume of beer employed. 6. — DETERMINATION OF THE DEGREE OF FERMENTATION. Calculate from the formula jy_ 100 sp G in which D is the degree of fermentation, sp the specific gravity of the dealcoholized beer, and G the gravity of the original wort. 7. — DETERMINATION OF TOTAL ACIDS. Heat 20 cc of the sample to incipient boiling to liberate carbon dioxid, and titrate with decinormal sodium hydroxid, using neutral litmus paper as indicator. Each cubic centimeter of decinormal alkali employed is equivalent to 0.009 grams of lactic acid. The number of cubic centimeters of decinormal alkali employed in titrating 20 cc of beer is multiplied by 0.045 for the acidity expressed as grams of lactic acid per 100 cc. 8. — DETERMINATION OF VOLATILE ACIDS. Follow the directions given for the determination of volatile acids in wine (p. 84) . This determination is rarely of value in sound beer. 9. — DETERMINATION OF REDUCING SUGAR. Proceed as directed on page 85, but boil four minutes instead of two. Express the result in terms of maltose equivalent to copper reduced, according to Table IX. 10. — DETERMINATION OF DEXTRIN. Deduct from the extract the sum of the maltose, protein, glycerol, total acids, and ash. While this method is only approximate, it is sufficiently accurate for most purposes. If a more accurate determination is desired, 50 cc may be treated by Sachsse's method for the hydrolization of starch, and dextrose determined by copper reduc- tion, according to Allihn's method. From the amount of dextrose so found, 95 per cent of the amount of maltose present in the beer is deducted (20 parts maltose are equivalent to 19 parts dextrose) and the remainder multiplied by 0.9. 11. — DETERMINATION OF GLYCEROL. Proceed as directed on page 82. The milk of lime is added during evaporation after the carbon dioxid has been expelled. 12. — DETERMINATION OF ASH. Evaporate 25 cc to dryness, ignite as directed on page 83, and weigh. 13. — DETERMINATION OF PHOSPHORIC ACID. Employ the official gravimetric or volumetric method,0 using the residue obtained in the determination of ash. 14. — DETERMINATION OF PROTEIN. Employ the Kjeldahl or the Gunning method for the determination of nitrogen, and multiply the result by 6.25. • U. S. Dept. of Agr., Div. of Chem., Bui. 46, p. 13. FERMENTED AND DISTILLED LIQUOKS. 95 15. — DETERMINATION OF CARBON DIOXID. (a) BOTTLED GOODS. Pierce the cork with a champagne tap. a Connect with a suitable absorption appa- ratus, placing an Erlenmeyer flask between the bottle and absorption tubes to allow the bubbles to break and prevent them from passing beyond it. The accompanying illustration (fig. 3) of an apparatus devised by Crampton and Trescotb answers admi- rably for this purpose. Immerse the bottle in water in a suitable vessel — such as an ether can with the top cut away, as shown in the cut — allow the gas to escape slowly, and when it ceases to flow spontaneously heat gradually to about 80° C. and maintain this temperature for about half an hour, shaking the bottle from time to time. Then disconnect the bottle, replace it with a soda-lime tube and draw a current of air through the apparatus. The increase in weight of the absorption tube gives the amount of carbon dioxid. The volume of beer employed is also weighed or measured. FIG 3.— Apparatus for the determination of carbon dioxid. When the bottle containing the sample is closed with a patent stopper, the latter may sometimes be replaced by a rubber stopper fitted with stopcock tube. Where the pressure is so great that this is not practicable, such samples may be treated as directed under "Bulk Goods." (b) BULK GOODS. Close a round-bottom flask of about 700-cc capacity with a two-hole rubber stop- per fitted with two stopcock tubes bent at right angles —one passing to the bottom of the flask and the other ending just below the stopper. c Produce a partial vacuum in the flask by means of an aspirator, and weigh the flask. Dip the end of one of the stopcock tubes below the surface of the beer, or, better, attach it by means of a rubber tube to a champagne tap or small faucet screwed into the cask, and allow about 300 cc of the sample to enter the flask. Weigh the flask and contents, and proceed as directed under "Bottled Goods." Somewhat better results may be •Hassall, Food Adulteration S. & C. Used by Wiley (Am. Chem. .Jour., ISSti, 8, 200) in the examina- tion of koumiss, and by Crampton in the examination of beer. Crainpton found.it necessary to reurind the cocks and ream off the thread, leaving a smooth tube. U. S. Dept. of Agr., Div. of Chem., Ilul. i:i, pt. 3, p. 294. ' T. S. Dept. of Atfr., Div. of Chem., Bui. 13, pt. 3, p. 293. '•Windisoh ( Das chemische Laboratorium des Brauers, p. 247), employs ordinary glass tubes pro- vided with rubber tubing and screw cocks. 96 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. obtained by placing a reflux condenser between the flask and absorption apparatus, and heating the flask over a burner to the boiling point. Attach the other stopcock tube to a soda-lime guard tube and pass a current of air through the apparatus. The amount of carbon dioxid is ascertained by the increase in weight of the absorption tube. 16. — DETECTION OF PRESERVATIVES. Proceed as directed on pages 88 and 107. (C) DISTILLED LIQUORS. 1. — DETERMINATION OF SPECIFIC GRAVITY. Proceed as directed on page 82. Owing to the high alcohol content of distilled liquors, care must be exercised that the temperature at which specific gravity is determined be as nearly 15.6° C. as possible. 2. — DETERMINATION OF ALCOHOL. Measure 50 cc of the sample (at 15.6° C.) into a distilling flask, dilute with 100 cc of water, and proceed as directed on page 82. The sample of distilled liquor taken for the determination of alcohol is diluted more than in the case of wine because of the errors attending distillates high in alcohol, errors due to evaporation and to making up to volume at temperatures varying slightly from 15.6° C. All measure- ments must be made at about that temperature. 3. — DETERMINATION OF EXTRACT. Evaporate 100 cc to sirupy consistency and proceed as directed on page 83. 4. — DETERMINATION OF ASH. Proceed as directed on page 83. 5. — DETERMINATION OF ACIDITY. Titrate 100 cc with decinormal sodium hydroxid using phenolphthalein as indi- cator. The number of cubic centimeters employed is multiplied by 0.0060 for the acidity expressed in grams of acetic acid per 100 cc. 6. — DETERMINATION OF SUGAR. Proceed as directed on page 85. 7. — DETERMINATION OF FUSEL OIL. a The apparatus recommended for this determination is Brom well's modification of Roese's fusel-oil apparatus. (See fig. 4.) The reagents required are fusel-free alcohol that has been prepared by fractional distillation over caustic soda or caustic potash, rejecting the first one-fifth and the last three-fifths of the distillate, and diluted to exactly 30 per cent by volume (sp. gr. 0.96541 at 15.6° C.), chloroform, freed from water and redistilled, and sulphuric acid (sp. gr. 1.2857 at 15° C.). Distill slowly 200 cc of the sample under examination till about 175 cc have passed over, allow the distilling flask to cool, add 25 cc of water, and distill again till the total distillate measures 200 cc. Dilute the distillate to exactly 30 per cent by volumeb (sp. gr. 0.96541 at 15.6°). •Windisch, Arb. kais. Gesamt., Vol. V, p. 390. t> The following is an accurate method for diluting any given alcohol solution to a weaker solution of definite percentage: Designate the volume percentage of the stronger alcohol by V and that of the FERMENTED AND DISTILLED LIQUORS. 97 Now prepare a water bath, the contents of which are kept at exactly 15° C., and place in it the apparatus (covering the end of the tube with a rubber cap to prevent wetting the inside of the tube) and flasks containing the 30 per cent fusel-free alcohol, chloroform, sulphuric acid, and the distillate diluted to 30 per cent by volume. When the solutions have all attained the tem- perature of 15° C., fill the apparatus to the 20-cc mark with the chloroform, drawing it through the lower tube by means of suction, add 100 cc of the 30 per cent fusel-free alcohol and 1 cc of the sulphuric acid, invert the apparatus and shake vigorously for two or three minutes, interrupting once or twice to open the stopcock for the purpose of equal- izing pressure. Allow the apparatus to stand for one hour in water that is kept at the temperature51 of 15° C., turning occasionally to hasten the settling of the chloroform and note the volume of the chloroform. After thoroughly cleansing and drying the apparatus repeat this operation, using the diluted distillate from the sample under examina- tion in place of the fusel-free alcohol. The increase in the chloroform volume with the sample under examination over that with the fusel-free alcohol is due to fusel oil, and this difference (expressed in cubic centimeters) multiplied by the factor 0.663 gives the volume of fusel oil in 100 cc, which is equal to the percentage of fusel oil by volume in the 30 per cent distillate. This must be calculated to the percentage of fusel oil by volume in the original liquor. I''.rfi'.— \ sample of liquor contains 50 per cent of alcohol by volume. The increase in the chloroform volume with the 30 per cent fusel-free alcohol is 1.42 cc. The in- crease in the chloroform volume with the distillate from the liquor under examination diluted to 30 per cent is 1.62 cc; difference, 0.20 cc. The volume of fusel oil in 100 cc of the 30 per cent distillate, then, is 0.20 X 0.663=0.1326, and by the proportion 30:f>0::0.132l>:0.221 we obtain the per- centage of fusel oil by volume in the original liquor. 8. — DKTKKMIN >N OK ALDEHYDES.1 FIG. 4.— Bromwell's fusel-oil apparatus. Dissolve 0.5 grams of fuchsin in about 100 cc of water; add a solution containing the same weight of sulphurous acid (H2SOS); dilute to a liter and filter. With 1 volume of this reagent mix 2 volumes of the 30 percent distillate obtained in the determination weaker alcohol by v. Mix v volumes of the stronger alcohol with water to make V volumes of the product. Allow the mixture to stand till full contraction has taken place and till it has reached the temperature of the original alcohol and water and make up any deficiency in the V volumes with water. ]-:.raiin>lt. H is desired to dilute a distillate containing 50 percent of alcohol by volume until it contains :;<) percent. To 30 volumes of the 50 percent alcohol add enough water to make 50 volumes, or place 150 ce of the distillate in a 250-cc. flask, fill to the mark with water, mix, cool, and till to the mark again. Owing to the extreme diHiculty of preparing distillates of exactly :i() percent, slight variations may he corrected by increasing or decreasing the chloroform reading, as suggested l>y Sell, O.OtWcc for each 0.01 percent variation in strength of alcohol from 30 per cent. Such variation, however, should not d o.irj per cent. »The temperature must be held as nearly 15" ('. ;is possible. If any variations occur the eh!6ro- form must he. increased or. decreased 0.0-lf, cc for every degree above or below that temperature «;.-bck A: Stiit/.er, /.tschr. ang. Chem., ls;«, 132). '• Mfdicus Korscli. nber Lebeiism., |,v.i5. 2, 299. NO. <;:, <>t> 98 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. of fusel oil. Treat in the same manner and at the same time a solution of 30 per cent (by volume) aldehyde-free alcohol containing 0.05 grams of acetic aldehyde per liter. After two minutes, match the colors of the two mixtures by dilution of the stronger with 30 per cent aldehyde-free alcohol, or by means of a colorimeter, and express the result as acetic aldehyde. 9. — DETERMINATION OF ETHEREAL SALTS. After the determination of the volatile acids the neutralized distillate is transferred to a flask connected with a reflux condenser, treated with 25 cc of tenth normal sodium hydroxid, and boiled one-half hour. The flask and contents are then cooled, 25 cc of decinormal hydrochloric acid added, and the excess of acid titrated with sodium hydroxid, using phenolphtalein as indicator. The number of cubic centimeters of decinormal alkali used in this titration, multiplied by 0.0088, is equal to the weight in grams of ethereal salts (calculated as ethyl acetate) in the volume of liquor taken for the determination. 10. — DETERMINATION OF FURFUROL. a Treat 5 cc with 5 drops of colorless anilin and 8 drops of acetic acid. After fifteen minutes, compare colorometrically with 5 cc of a solution containing 0.05 grams of furfurol per liter which has been subjected to the same treatment. 11. — DETERMINATION OF COLORING MATTER. Proceed as directed under methods for the detection of coloring matter, (p. 111). For the detection of caramel use the method of Crampton and Simons, b which depends on the insolubility of caramel in ether. Evaporate 50 cc of the sample nearly to dryness on the water bath, wash into a 50-cc flask, add 25 cc of absolute alcohol, cool to a definite temperature, and dilute to mark with water. Transfer 25 cc to an apparatus of the general description of Brom well's fusel-oil apparatus (page 97), but graduated so that the lower bulb holds 25 cc to a definite mark on the stem, which may be of larger tare than in Brom well's apparatus. Add 50 cc of ether and shake at intervals for half an hour, let settle, and siphon water through the lower tube until the aqueous layer reaches the 25-cc mark. Mix the whole, remove the aqueous layer, and compare by means of a tintometer with the 25 cc of the solution which were 'not treated with ether. Express the amount of color removed on the percentage basis. XT.— BAKING POWDERS AND BAKING POWDER CHEMICALS. By A. L. WINTON, CJiemist of State Experiment Station, New Haven, Conn. All the processes hereafter described, except determination <>f acidity, may be employed in the analysis of baking powders, and all the processes, except deter- mination of carbonic acid, in the analysis of cream of tartar and its substitutes. The sample under examination is entirely removed from the package, carefully mixed, and passed through a sieve without grinding. 1. — DETERMINATION OF TOTAL CARBON DIOXLD.C This determination is made by the absorption method, and any apparatus may be employed which gives accurate results when checked with pure calcite. What- ever apparatus is chosen the tubes and materials used for absorbing and drying the carbon dioxid may be varied according to the preference of the analyst. Those "Windisch. Forsch. uber Lebens., 1897, 4, 369. "See Appendix, p. 156. 11 Jour. Am. Chem. Soc., 1890, 22, 810. BAKING POWDERS. 99 mentioned below are selected because the details have been carefully worked out by the originators. According to the amount of absorbent employed the weight of sodium carbonate or calcium carbonate may vary from 0.25 to 1.00 gram, and about twice as much baking powder may be used. The corrections for temperature and pressure given with the Heidenhain apparatus may ordinarily be disregarded. (a) KNORR'S APPARATUS. (1) Description of apparatus. This apparatus (fig. 5) employs only ground -glass joints, and maybe quickly made ready for use or taken to pieces and packed away. On the other hand, it is inflexible FIG. 5.— Knurr's apparatus for the determination of carbon dioxid: A, Distilling flask fitted to con- denser by a ground-glass stopper. H. Reservoir containing acid. C, Soda-lime tube fitted to acid reservoir by a ground-glass s'topper. 1), Condenser. E, Liebi'g bulb filled with sulphuric acid. F, Liebig bulb filled with a solution of potassium hydroxid for tin- absorption of carbon dioxid and followed by a calcium-clilorid tube-. An additional guard tube filled with soda lime should follow the tube F, though not shown in the cut. and must he «-an 'fully handled, and has the additional disadvantage that broken parts can not n-adily In- replaced. Therefore it is of more value for occasional determinations than for a long series. :i •The small calcium ehlorid tube shown in the cut attached to the potash bulb F is usually replaced by a second Liebig bulb filled with sulphuric acid. Better results are obtained if the same drying tubes aiv used before and after the potash bulb. Many analysts prefer to replace the bulb F and attached calcium ehlorid tube by two U-tubes filled with sifted soda liine. When the second tube shun - a material increase in weight it is placed first, and the first tube refilled and placed in the second position. 100 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. (2) Materials. The potassium hydroxid solution usually employed for absorbing carbon dioxid has a specific gravity of about 1.27. Many analysts, however, prefer a solution naving a specific gravity of 1.55. The calcium chlorid and soda lime employed should be finely granulated and freed from dust with a sieve. (3) Manipulation. The quantity of baking powder to be examined is placed in a distilling flask, which must be perfectly dry. a The flask is closed with a stopper carrying the tube connecting with the absorption apparatus and also with the funnel tube. The tubes in which the carbon dioxid is to be absorbed are weighed and attached to the apparatus. In case two Liebig bulbs are employed, one for potassium hydroxid and the other for sulphuric acid, to absorb the moisture given up by the potassium hydroxid solution, it will be necessary to weigh them separately. If two soda-lime tubes are employed it will be found advantageous to weigh them separately and fill the first tube anew when the second tube begins to increase in weight materially. The tube B is nearly filled with hydrochloric acid (sp. gr. 1.1), and the guard tube C placed in position. The aspirator is now started at such a rate that the air passes through the Liebig bulbs at the rate of about two bubbles per second. The stopper of the funnel tube is opened and the acid allowed to run slowly into the flask, care being taken that the evolution of gas shall be so gradual as not to materially increase the current through the Liebig bulb. After the acid has all been introduced, the aspiration is continued, when the contents of the flask are gradually heated to boiling, the bulb in tube B being closed. While the flask is being heated the aspirator tube may be removed, although many analysts prefer when using ground-glass joints to aspirate during the entire operation. The boiling is continued for a few minutes after the water has begun to condense in D, when the flame is removed, the valve in the tube B opened, and the apparatus allowed to cool with continued aspiration. The absorption tubes are then removed and weighed, the increase in weight being due to carbon dioxid. (b) HEIDENHAIN'S APPARATUS. (1) The apparatus. This was originated by G. J. Mulder and recommended and improved by Kolbe, Stolba, and Fresenius, b and has been modified by H. Heidenhain, c as shown in Fig. 6, which is drawn on a scale of 1 : 12. It consists of— A. A cylinder filled with soda-lime to free the air from carbon dioxid. A thick layer of cotton prevents soda-lime dust from being carried over. B. Glass cock to regulate the air current, which finds resistance at C. C. A capillary contraction. D. Funnel tube of peculiar shape. The funnel is cylindrical, three-fourths of an inch wide and 4 inches long, and is reduced to half its width at the bottom, so as to make a neck for a perforated rubber stopper into which— E. A glass tube is tightly fitted, allowing the stopper to be taken out and put in by the glass tube. F. Evolution flask, ordinarily of 150-cc capacity, for foaming liquids of 300-cc capacity. G. Return condenser, simply a glass tube of one-foarth of an inch bore, around which a small lead pipe is wound. The tube following the condenser con- tains a few pieces of calcium chlorid, to retain the bulk of the moisture. It is refilled when contents are liquefied. •Sec Appendix, p. 157. «> Quant. Anal., vol, 1, p. 449, and vol. 2, p. 308, German edition. cJour. Am. Chem. Soc., 1896, 18, 1. BAKING POWDERS. 101 H. TJ-tube filled with coarse calcium chlorid. K. Filled at I with a 3-inch long column of pumice stone impregnated with copper sulphate completely dehydrated at 150° C. The rest is filled with fine calcium chlorid. L. Cock to close the apparatus when not in use. M. First absorption tube about one-half inch in diameter and 5 inches long, filled mainly with soda-lime, with a little calcium chlorid at the side at which the air current enters. N. Second absorption tube of same size as M, filled half with soda-lime and half with calcium chlorid. Place the side containing calcium chlorid toward the end of the apparatus where the air current leaves. O. Guard-tube containing calcium chlorid toward N and soda-lime toward P. P. Indicator tube trapped with glycerin. R. Safety bottle to receive water which may be sucked back from — S. The aspirator, which is a Mariotte's bottle of about 4 liters capacity. (2) Materials. Use calcium chlorid dehydrated at 200° C, not fused. Grind it coarsely in a coffee mill and sift through No. 18 wire gauze to remove the extremely coarse, and through No. 30 wire gauze to remove the very fine. Prepare a large quantity of such calcium chlorid at the beginning and use this for the tubes K, M, and N. The reason for this is that the current of air must leave the weighed tubes with the same content of moisture as it entered them, which only can be attained if the absorbent in K and N is of the same nature and quality. The soda-lime* for the weighed tubes is ground and sifted in the same way. It should not be too dry, as it must not absorb moisture to a higher degree than calcium chlorid. The tubes M and N should hold about 20 grams filling each, making M's capacity for carbon dioxid almost 1 gram and N's capacity for moisture 0.2 gram. M should be refilled when its weight has increased 0.75 gram, and N after an increase of 0.1 gram in weight. Use best rubber for all connections, applying a trace of castor oil as lubricator. For connections of the weighed tubes use rubber tubing boiled in weak lye, washed and dried. Apply also a little castor oil, which is thoroughly wiped off again before connecting the tubing. Before using the apparatus fill H and K with carbon dioxid, in order to saturate the alkalinity of the calcium chlorid, and exhaust after several hours. (3) Manipulation. Weigh M and N, taking precaution that they are of the same temperature as the air in the balance-room. Shortly before weighing, open the tubes for a moment to allow equalization of air. Note thermometer and barometer. Connect tubes with the apparatus and make sure that all joints are tight by closing A at the bottom, opening all cocks, starting the aspirator and observing P, in which the liquid must soon come to a standstill. Then disconnect the aspirator, close B, remove F, put in the substance b (use about 1 gram of sodium carbonate or calcium carbonate, or about 2 grams of baking powder), connect F, and start the cooler. Fill acid and water through D, lifting E slightly and allowing only small quantities of the acid and water to enter at the time. (Use only water made free from carbon dioxid by boiling. ) Light the burner, heat to boiling, and reduce the flame to keep the liquid just at the boiling point. If no more air passes P, start the aspiration. When water stops running, open B carefully and adjust the outflow of the aspirator by raising or lowering the syphon to half the safe speed. »An excellent method for the preparation of soda-lime is given by Benedict and Turner, Jonr. Amer. Chein. Hoc., 1K99, 21, 396. '•Set- Appendix, p. 167. 102 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. (In order to find the allowable rapidity of the air current proceed as follows: Charge the apparatus exactly as for an analysis, leaving out the carbonate. Start to aspirate at the rate of about 50 cc per minute. After two liters have been aspirated weigh the tubes. If they have lost in weight, repeat the experiment with 40 cc per BAKING POWDERS. 103 minute, and so on until the weight of the tubes remains constant. If the work has been done with =0.0000015 gram. From above follows: Volume of tubes and fillings =— -f-— 2.7 z.O f^ i i^ Volume of brass weights ~f~ 8.5 and G F G+F 2.7^2.0 8.5 representing the differential volume affected by temperature and pressure and teing a constant for the tubes. Now, T = V X 0. 0000039 gram, and B = V X 0.0000015 gram. Observe that rise of temperature makes the air lighter, consequently the tubes heavier. Therefore the correction must be negative. On the other hand, increased pressure has the opposite effect, making the correction positive. Example: G = 80. F = 40, from which follows V =35.5, and T =0.00014 gram, and B =0.00005 gram. Now, if A1 =25°, A2 = 27°, B1 = 759mm, B8a=766mm, then the correction for temperature will be — — 0.00028 gram, and for air pressure — — 0.00015 gram, making a total <>'' — 0.00043 gram. 104 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. 2. — DETERMINATION OF RESIDUAL CARBON DIOXID. a Weigh 2 grams of baking powder into a flask suitable for the subsequent deter- mination of carbonic acid, add 20 cc of cold water, and allow to stand 20 minutes. Place the flask in a metal drying cell surrounded by boiling water, and heat with occasional shaking for 20 minutes. To complete the reaction and drive off the last traces of gas from the semisolid mass, heat quickly to boiling over a lamp, and boil for one minute. Aspirate until the air in the flask is thoroughly changed, and determine the residual carbon dioxid by absorption, as described under total carbonic acid. The process described, b based on the methods of McGill c and Catlin, d imitates as far. as practicable the conditions encountered in baking, but in such a manner that concordant results may be readily obtained on the same sample, and comparable results on different samples. 3. — DETERMINATION OF AVAILABLE CARBON DIOXID. Subtract the residual carbon dioxid from the total. 4. — DETERMINATION OF ACIDITY. (For cream of tartar and its substitutes.) Dissolve one gram of the material in hot water and titrate with standard fifth- normal potassium hydroxid solution, using phenolphthalein as indicator. 5. — DETECTION OF TARTARIC ACID, FREE OR COMBINED. e Applicable in presence of phosphates. Shake repeatedly about 5 grams of the sample with about 250 cc of cold water in a flask and allow the insoluble portion to subside. Decant the solution through a filter and evaporate the filtrate to dryness. To the dry powdered residue add a few drops of a 1 per cent solution of resorcin and about 3 cc of strong sulphuric acid. Heat slowly. A rose-red color indicates tartaric acid, the color being discharged on dilution with water. 6. — DETECTION OF FREE TARTARIC ACID. Extract 5 grams of the powder with absolute alcohol and evaporate the alcohol from the extract. Dissolve the residue in dilute ammonia, transfer to a test tube, add a good-sized crystal of silver nitrate, and heat gently. Tartaric acid is indicated by the formation of a silver mirror. If desired, the absolute alcohol extract may be tested by the Wolff method, as described under 5. 7. — DETERMINATION OF TOTAL TARTARIC ACID. f The following is the Goldenberg-Geromont-Heidenhain method, applicable only in the absence of aluminum salts, calcium salts, and phosphates: Into a shallow porcelain dish, 6 inches in diameter, weigh out 2 grams of the material and sufficient potassium carbonate to combine with all tartaric acid not in the form of potassium bitartrate. Mix thoroughly with 15 cc of cold water and add 5 cc of 99 per cent acetic acid. Stir for half a minute with a glass rod bent near the end. Add 100 cc of 95 per cent alcohol, stir violently for 5 minutes and allow to settle at least 30 minutes. Filter on a Gooch crucible with a thin layer of paper pulp, and wash with 95 per cent alcohol until 2 cc of the filtrate do not change the »See Appendix, p. 157. fcConn. Agr. Exp. Sta. Rep., 1900, p. 169. « Lab. Inland Rev. Dept., Ottawa, Canada, Bui. 68, p. 31. d Baking powders. A Treatise on the Character, Methods for Determination of the Values, etc. , p. 20. •Wolff, Rev. ehim. anal, appl., 1899, 4, 263. f See Appendix, p. 158. BAKING -POWDERS. 105 color of litmus tincture diluted with water. Place the precipitate in a small casserole, dissolve in 50 cc of hot water and add standard fifth-normal potassium hydroxid solution, leaving it still strongly acid. Boil for one minute. Finish the titration, using phenolphthalein as indicator and correct the reading by adding 0.2 cc. One cubic centimeter of fifth-normal potassium hydroxid solution is equivalent to 0.026406- gram tartaric anhydrid (C4H405), 0.03001 gram tartaric acid (H2C4H4O6), and 0.03763 gram potassium bitartrate (KHC4H4O6). The standard of the potassium hydroxid solution should be fixed by pure dry potassium bitartrate. The accuracy of this method is indicated by the agreement of the percentages of potassium bitartrate in cream of tartar powders containing no free tartaric arid, obtained by calculation from the tartaric acid, with those obtained by calculation from the potassium oxide. a 8. — DETERMINATION OF STARCH. (a) DIRECT INVERSION METHOD. (For all baking powders and baking chemicals free from lime.) Weigh 5 grams of the powder into a graduated 500 cc flask. Convert into dextrose by the Sachsse's method and determine the reducing power of the solution by the Allihn method, as described under Spices (p. 57). (b) INDIRECT METHOD. b (For phosphate, alum phosphate, and all other baking powders containing lime.) Mix 5 grams of the powder in a graduated 500-cc flask, with 200 cc of 3 per cent hydrochloric arid, and allow the mixture to stand for one hour, with frequent shak- ing. Filter on a Schleicher and Schuell No. 575 11 cm hardened filter, taking care that a clear filtrate is obtained. Rinse the flask once, without attempting to remove all the starch, and wash the paper twice with cold water. Carefully wash the starch from the paper bark into the flask, with 200 cc of water, using a small wash bottle. Add 20 cc of 25 per cent hydrochloric acid and proceed according to Sachsse's method. Determine reducing power by Allihn's method. The treatment with 3 per cent hydrochloric acid, without dissolving the starch, effectually removes the lime, which otherwise would precipitate as tartrate in the alkaline copper solution (c) M'GILL METHOD. The following modification of McGill's method is valuable for check purposes: Digest one gram of tin- powder with 150 cc of 3 per cent hydrochloric acid for 24 hours at the room temperature, with occasional shaking. Filter on aGooch crucible, wash thoroughly with cold water and finally once with alcohol and once with ether. Dry at 110° C. (4 hours is usually sufficient), cool and weigh. Burn off the starch and weigh again. To obtain the weight of starch subtract the weight after burning from the weight after drying at 110° C. The results by this method on cream of tartar powders and tartaric acid powders a.nive closely with those obtained by copper reduction. On phosphate, alum, and alum-phosphate powders the results are usually satisfactory, but in some instances they may be over 2 per cent too high. 9. — DETERMINATION OK I'OTASSITM BITARTRATK. If, as is usually the case, no other potassium salt but the bitartrate is present, multiply the percentage of total potash determined as directed under 12, d, by 3.MM>. •Conn. \nr. Kxp. Stn. Krp.. 1900, p. 180. «>Aftrr Wintoii. Conn. Ajrr. Kxp. Shi. Ui'p.. I'.HKI, p. 171. 10() PROVISIONAL METHODS FOR ANALYSIS OF FOODS. 10. — DETERMINATION OF FREE TARTARIC ACID. Calculate the percentage of tartaric anhydrid combined with the potash as bitar- trate (if any) and subtract this from the percentage of total tartaric anhydrid. The difference is the tartaric anhydrid originally added as the free acid, although if the sample has been kept for a long time or has been improperly stored, a portion or all of this acid may exist at the time of analysis as the sodium salt resulting from the reaction in the can with the sodium bicarbonate. Multiply by 1.1365 to obtain the percentage of tartaric acid. 11. — DETECTION OF ALUM IN PRESENCE OF PHOSPHATES.* (a) IN BAKING POWDER. Burn to an ash about 2 grams of the sample in a platinum dish. Extract with boiling water and filter. Add to the filtrate a few drops of ammonium chloride solution. A flocculent precipitate indicates alum. (b) IN CREAM OF TARTAR. Mix about 1 gram of the sample with an equal quantity of sodium carbonate, burn to an ash, and proceed as in (a). 12. — EXAMINATION OF Asn.1' (a) DETERMINATION OF INSOLUBLE ASH AND PREPARATION OF SOLUTIONS: Char 5 grams of the material in a platinum dish at a heat below redness. Boil the carbonaceous mass with dilute hydrochloric acid, filter into a graduated 500-cc flask, and wash with hot water. Return the residue, together with the paper, to the plati- num dish and burn to a white ash. Boil again with hydrochloric acid, filter, wash, unite the two filtrates, and dilute to 500 cc. Incinerate the residue after the last filtration for the determination of ash insoluble in acid. (b) IRON AND ALUMINA. c Draw an aliquot portion of 100 cc and separate silica, if necessary. Mix the solu- tion with sodium-phosphate solution in excess of what is required to form normal aluminum phosphate. Add ammonia until a precipitate remains on stirring, then hydrochloric acid drop by drop until the precipitate dissolves. Heat the solution to about 50° C., mix with a considerable excess of 50 per cent ammonium-acetate solu- tion and 4 cc of 80 per cent acetic acid. As soon as the precipitate of aluminum phosphate, mixed with a little iron phos- phate, has settled, collect on a filter, wash with hot water, ignite, and weigh. Fuse the mixed phosphates with ten parts of sodium carbonate, dissolve in dilute sulphuric acid, reduce with hydrogen sulphid and determine the iron by the vol- umetric permanganate method. In the same solution determine the phosphoric acid. To obtain the weight of A12O3, subtract the sum of the weights of Fe2O3 and P./.)5 from the weight of the mixed phosphates. (c) LIME. Heat the filtrate from the mixed phosphates, which is acid with acetic acid, to 50° C. and precipitate with ammonium oxalate. Filter, wash, ignite over a Bunsen burner, and finally convert into oxid by heating over a blast lamp. "Thirty-first An. Rep. Mass. SUito Board of Health, 1899, p. 638. 1 •c.mn. Agr. Exp. St.. lt.-p. I'.NK), p. ITS. • See Appendix, p. Kill. FOOD PRESERVATIVES. 107 (d) POTASH AM) SODA. a Evaporate an aliquot portion of the solution, prepared as described, nearly to dry- ness to remove the excess of hydrochloric acid, dilute, and heat to boiling. While still boiling, add barium chloride solution as long as a precipitate forms and enough barium hydrate to make the liquid strongly alkaline. As soon as the precipitate has settled, filter and wash with hot water, heat the filtrate to boiling, add sufficient ammonium carbonate solution (1 part of ammonium carbonate in 5 parts of 2 per cent ammonia water) to precipitate all the barium, filter, and wash with hot water. Evaporate the filtrate to dryness, ignite below redness to remove ammonia salts. Add to the residue a little water and a few drops of ammonium carbonate solution. Filter into a tared platinum dish, evaporate, ignite below redness, and weigh the mixed potassium and sodium chlorids. Determine the potash as potassium platinichlorid, using the factors 0.1939 for K2O and 0.3069 for KC1. 13. DKTKKM I NATION ol 1'lIoSPHORIC AdD. Mix 5 grams of the material with a little magnesium-nitrate solution, dry, ignite, and dissolve in hydrochloric acid. In an aliquot of the solution determine phos- phoric acid as magnesium pyrophoephate by the molybdic method.1' 14. — DETERMINATION 01- si I.IMII UK AC-ID. Boil 5 grams of the powder gently for one and one-half hours with a mixture of 300 cc of water and 15 cc of concentrated hydrochloric acid. Dilute to 500 cc, draw off an aliquot portion of 100 cc, dilute considerably, precipitate with barium chlorio!, filter through a Gooch crucible, ignite, and weigh. Direct solution of the material without burning of the organic matter was proposed by Crampton. c The dextrose, formed by the action of the acid on the starch of baking powders, does not interfere with the accuracy of the process.'1 15. — DETERMINATION OF AMMONIA. Ammonia alum is often an ingredient of cream-of-tartar substitutes and baking powders, and ammonium carbonate is occasionally present in baking powders. Deter- mine ammonia by distillation with caustic soda into standard acid and tit-ration. XVI. FOOD PRESERVATIVES. By W. M. ALLKN, Stotfe Department of Agriculture, I!, purl :>. p. 596. •'Conn. Atfr. Kxpl. Sin., Urp. 1(.M)<», p. 111). 108 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. (b) FIRST METHOD OF DETECTION. To about 5 cc of the distillate described above add 2 or 3 drops of a 1 per cent aque- ous solution of phenol; mix and carefully pour it on about the same amount of con- centrated sulphuric acid in a test tube, holding the tube so that the solutions will not mix. The presence of one part of formaldehyde in 100,000 parts is indicated by the formation of a crimson color at the plane of union of the solutions. If the formalde- hyde be present in greater quantity, a white turbidity, or a light-colored precipita- tion, will be formed above the coloring. If organic matter is distilled over, the charring of it by the sulphuric acid may be mistaken for a trace of formaldehyde; but, on allowing the test to stand for twelve hours, the coloration, if due to formaldehyde, will become a whitish turbidity instead of the dark color which appears if due to the charring of organic matter. Some other aldehydes will give the same result, and it is, therefore, not conclusive. (c) SECOND METHOD OF DETECTION.* Add about 5 cc of the distillate obtained under (a) to an equal volume of pure milk in a porcelain casserole, and about 10 cc of concentrated hydrochloric acid con- taining 1 cc of 10 per cent ferric chlorid solution to each 500 cc of acid. Heat to 80° or 90° directly over the gas flame, holding the casserole by the handle and giving it a rotary motion to break up the curd. A violet coloration indicates formaldehyde. (d) THIRD METHOD OF DETECTION. Dissolve 1 gram of phenylhydrazin hydrochlorid and 1.5 grams of sodium acetate in 10 cc of water. To 1 cc of distillate obtained as directed in (d) add 2 drops of reagent and 2 drops of sulphuric acid. If formaldehyde is present, a green color will be produced. 2. — DETECTION OF SULPHUROUS ACID. Prepare samples as directed under 1 (a), and boil 20 cc of the distillate after the addition of a few drops of bromin or iodin solution. If it is decolorized quickly, test for sulphuric acid with barium chlorid solution. If sulphurous acid or sulphite is present, determine it quantitatively as directed under wine (page 90). 3. — DETECTION OF SALICYLIC ACID. If the material be a solid or semisolid, macerate 200 to 300 grams in a mortar with about 400 cc of water made slightly alkaline with sodium or potassium hydroxid, and strain through a cotton bag. Acidify the nitrate with dilute (1:3) sulphuric acid, and extract by shaking with about 30 cc of chloroform or ether. b Separate from the water with a separatory funnel. If a clear solution is obtained, place the chloroform or ether in a small porcelain dish and evaporate at a low temperature. If an emul- sion is formed and a clear solution will not separate out on standing, whirling in a Babcock milk tester or some other centrifugal machine will usually give the desired clear solution. Take up the residue in the porcelain dish with 3 or 4 cc of hot water and divide into two portions, one for salicylic acid and the other for saccharin. In the case of materials containing large amounts of extractive matter, and those from which the water solution can not be separated from the solid matter by strain- ing, it may be found necessary to separate them by distillation, though straining is always preferable. In such cases acidify the macerated material with phosphoric acid, and transfer to a distilling flask, with a very short neck and wide mouth. An Erlenmeyer flask with inside diameter of mouth l\ inches is a good shape. The Leach, Twenty-ninth An. Rep. Mass. Board of Health, 1897, p. 658. b See appendix, page 160. FOOD PRESERVATIVES. 109 tube connecting the flask with condenser should be very short, with an inside diam- eter of not less than f inch, and should turn into the condenser immediately above the stopper in flask. Conduct steam through a small tube passing through the stop- per and dipping deeply into the material in the flask. Submerge the distilling flask almost to the stopper in a linseed oil bath and distill with temperature of the oil at from 120° to 130° C. Care must be taken not to let the contents of the flask get too low, as the heat will decompose the organic matter. The temperature in the flask will go but little above 100° C. unless the solution in the flask is allowed to get too low. Distill off 500 cc to 600 cc, acidify with dilute sulphuric acid, extract with about 30 cc of chloroform or ether, and proceed as directed above. (a) SACCHARIN. If the solution for saccharin and salicylic acid has an intensely sweet taste, it is an indication of saccharin. If it is sweet, dilute a portion of it about ten times, and taste again. (See also page 51.) (b) SALICYLIC ACID. (1) First method.* Place a few drops of solution for salicylic acid in a porcelain dish, add 2 or 3 drops of ferric chlorid solution in such a way that the solutions will come together slowly, which will give a purple or violet color if salicylic acid is present. (2) Second method.* Place about 0.5 cc of the solution in a porcelain dish and evaporate to dry ness at a low temperature Warm the'residue carefully with one drop of concentrated nitric acid, and add 2 or 3 drops of ammonia until alkaline. The presence of salicylic acid is indicated by the formation of a yellow color of ammonium picrate, and maybe confirmed by dyeing a thread of fut-1'ivc wool in it. 4. — DKTWTION OK I'.KN/OH Ann.1' Separate benzole acid by extraction or distillation as directed under salicylic acid, and test by one of the following methods: (1) Firxf nnihod.c Divide solution for benzoicaci• U. S. Dept. of Agr., Div. of Chem., Bui. 51, p. 113. c Thomson's method— Button's Volumetric Analysis, page 100. COLORING MATTER. Ill XVII.— COLORING MATTER. By L. M. TOLMAN, Bureau of Chemistry, U. S. Department of Agriculture. 1. — GENERAL DISCUSSION. The food chemist has two problems in connection with coloring matter — the analy- sis of dyes used for food colors and the detection and identification of the color used in a food. The first will require an estimation of the hea\7y metals present and a determination of the general group to which the color belongs. The second will require the detection of the presence of the color, the determination of the group to which the color belongs, and the presence or absence of poisonous metals. The complete examination of dyes is too large a subject to take up in these methods, and one will have to refer to such works as Schultx and Julius, on Organic Coloring, Allen's Commercial Organic Analysis, and others that go into the subject in an exhaustive manner. The determination of the general nature of the dye can be made by the use of Rota's scheme, which is the simplest of the many different methods proposed and is quite satisfactory, although it requires a great deal of care and experi- ence. The detection of the color in a food product and its identification are more difficult. It must be separated in a somewhat pure condition and then tested. Almost all the methods for separating added color from the food will take up some of the natural color of the food as well. As will be seen in tables for the extraction of fruit colors (p. 113), amyl alcohol extracts the coloring matter from many fruits, and these extracts may easily be mis- taken for added colors. Some of the highly colored fruit juices will dye wool, and the color will be perma- nent; but these will not be mistaken lor coal-tar dyes if the double-dyeing method is followed. In the methods of manufacture of coal-tar dyes many become contaminated with poisonous metals, such as arsenic, copper, xinc, tin, and lead. There i> always the possibility of the presence of arsenic, as sulphuric acid is used at one stage or another in the preparation of nearly every dye. Some colors have metallic atoms in their molecule, such as malachite green, which is a double chlorid of /inc in combination with the organic -roup. Many vegetable colors are sold as lakes of tin or alum. Other colors are known to have a toxic action, such as picric acid and naphthol yellow. Mixtures of two or more dyes are often added to foods. This can sometimes be shown by a system of fractional dyeing, when- the dyes are taken up at different rates by the fabric. In examining mixtures of red, orange, and blue dyes, which are widely sold for coloring wine, the writer found that the woolen cloth took up the red much faster than the orange, and the blue slowest; so that the first piece of cloth dyed was red; the second, a lighter shade; the third, greenish, and the fourth, Muish. 2. — DKTKH.M i NATION OK HKAVY MKTALS. Directions for this determination are given under Vegetables ( p. .V_M. 3. — DKTKHM i NATION OF COAL-TAR COLOKIM; MATTKKS in DYKINC, WOOL. (a) MKTIIOl) OF SOSTKONI A N I » < A KI'KNTI ERI. !l From 10 to L'O grams of the sample are dissolved in 100 ec of water, filtered if neces- sary, acidified with from 2 to 4 cc of 10 per cent solution of hydrochloric acid, and a piece of woolen cloth, which has been washed in a very dilute solution of boiling •Ztsch. until, riirm.. isw. :&;,. :;MT; I. s. Dcpt. of Agr., Div. of Chem., 13ul. 4(i revised, p. 68, 112 PROVISIONAL METHODS FOE ANALYSIS OF FOX)DS. potassium hydroxid and then washed in water, is immersed in it and boiled for five to ten minutes. The cloth is removed, thoroughly washed in water, and boiled with very dilute hydrochloric acid solution. Then after washing out the acid the color is dissolved in a solution of ammonium hydroxid (1 to 50). With some of the dyes solution takes place quite readily, while with others it is necessary to boil some time. The wool is taken out, a slight excess of hydrochloric acid is added to the solution, another piece of wool is immersed and again boiled. With vegetable coloring mat- ter this second dyeing gives practically no color, and there is 110 danger of mistaking a fruit color for one of coal-tar origin. It is absolutely necessary that the second dyeing should be made, as some of the coal-tar dyesa will dye a dirty orange in the first acid bath which might be easily passed for vegetable color, but on solution in alkaline bath the second acid bath dyes a bright pink. (b) ARATA'S METHOD. b This method gives results comparable with those of the first dyeing of the preced- ing method. It was recommended for detecting coal-tar colors in wine, and has been used by Winton ° in fruit products. From 20 to 30 grams of the sample dissolved in 100 cc of water are boiled for ten minutes with 10 cc of a 10 per cent solution of potassium bisulphate and a piece of white wool or woolen cloth which has been previously heated to boiling in a very dilute solution of sodium hydroxid and thoroughly washed in water. After removal from the solution the wool is washed in boiling water, and dried between filter papers. If the coloring matters are entirely from the fruit the wool will be either uncolored or will take on a faint pink or brown, which is changed to green or yellow by ammonia and not restored by washing. In addition to this, it is advisable in all cases to dissolve out the coloring matter with ammonia as in the first method and dye again, since Arata's method gives prac- tically the same results as the first dyeing in hydrochloric acid bath and needs to be substantiated by the second dyeing. Another advantage in the second dyeing is that if a large piece of woolen cloth is used in the first dyeing, and a small piece in the second dyeing, small amounts of coloring matter can be brought out much more decidedly in the second dyeing where practically all of the vegetable coloring matter has been excluded. The col- oring matter can be identified to a certain extent by the schemes of Witt, d Allen, Weingartner, eDommergue, f Girard g and Dupre, and Rota. h The tests can be made1 directly on the dyed fabric or the dye can be dissolved out. j To remove the color wash the wool with dilute tartaric acid and then with water and dry between filter paper. Saturate the wool with strong sulphuric acid and press out the color with a glass rod after from five to ten minutes and dilute to 10 cc with water. Remove the wool, make solution alkaline with ammonia, and when cold extract with from 5 to 10 cc of amyl alcohol. Separate the amyl alcohol, evaporate it to dryness, and test the residue with strong sulphuric acid. Ponceau R, 2R, 3R. S and 3S gives yellow red to carmine red. Ponceau S and tropaeolin O give yellow to orange yellow. »U. S. Dept. of Agr., Bureau of Chem. Bui. 66. t>Ztschr. anal. Chem., 1889, 28, 639. <=Conn. Exp. Sta. Report, 1899, Pt. II, p. 131. aztschr. anal. Chem., 1887, 26, 100. •Com. Org. Anal., Vol. Ill, pt. 1, pp. 399-420. 'Ztsch. anal. Chem., 1888, 27, 232-249. sZtsch. anal. Chem., 1890, 29, 369-377. h Analyse des Matieres Alimentaires, etc., 583-593. i Analyst, 1899, 24, 41. JZtsch. anal. Chem., 1889, 28, 639; Borgmann, Anal, des Weines, p. 91; Winton, Conn. Expt. Sta. K< •!>!., 1899, Pt. II, p. 131. COLORING MATTKK. 118 Biebrich scarlet gives a green; Bordeaux red and crocein scarlet give blue; tropae- olin OO< ) and solid red give violet. If the wool is well dyed most of these colors may be obtained on the fabric. This gives only the reactions of a few of the more common colors. In order to carry the work farther the more complete works referred to will have to be used. 4. — DETECTION OF COAL-TAR COLORS BY EXTRACTION WITH SOLVENTS. In the Paris Municipal Laboratory* the following scheme of extraction of coal-tar colors is used: The acid colors, sulphu-fuchsin, azo derivatives, and phthaleins are not precipitated by tannin and are insoluble or only slightly soluble in acetic ether or arnyl alcohol. The basic colors (fuchsin, safranin, etc.) are precipitated by tannin and readily soluble in acetic ether or amyl alcohol. I. To 50 cc of wine add ammonium hydroxid in slight excess; then add 15 cc of amyl alcohol, shake, and allow to stand. 1. If the alcohol be colored red or violet, decant, wash, filter, evaporate to dryness in presence of a piece of wool, and test the dyed wool with sulphuric acid. 2. If the alcohol be not colored, separate, and add acetic acid. If the alcohol becomes colored the presence of basic aniline color is indicated. 3. If the amyl alcohol is uncolored, both before and after the addition of acetic acid, no basic coal-tar color is present. II. Add an excess of calcined magnesia and then a 20 per cent solution of mercuric acetate and bring to a boil. A coloration before or after addition of acetic acid indi- cates the presence of coal-tar dyes, particularly acid dyes. III. Extract the solution with acetic ether made alkaline by barium hydroxid. Tli is dissolves basic colors. In any case the colors must be fixed on wool, as many of the fruit colors are extracted and will give reactions with sulphuric acid, which may be mistaken for coal-tar colors. The extraction of fruit colors is shown in the following tables, the first of which was prepared by Truchon and Martin-Claude, b and the second by the writer. The fresh fruit juice was very slightly acidified by hydrochloric acid before extraction. In no case in the dyeing test was there any danger of mistaking the vegetable color for one of coal-tar origin where the double-dyeing method was used. Extraction of fruit colors with amyl-alcohol. Fruit. Coloration of acid solu- tion." Coloration of ammoniacal solution. Addition of a drop of Juice. Amyl-alcohol extract. Juice. Amyl-alcohol extract. H2SO4 to dyed fabric. Early cherries Red .. Yellow Uncolored .. ROM- Green ! Green •ireell ( ircfii Uncolored . Uncolored . Uncolored . Uncolored . Uncolored . Uncolored . Uncolored . Uncolored. Yellow-red Yellow-red Yellow-red Yellow-red Yellow-red Yellow-red Yellow. Yellow. j Rose. Rose (dyes silk a rose red). Dyes silk rose. Uncolored. Ripe cherries Karlv strawberries Red Red Kipe >t ra wherries Red Red Ka-plM'ITies Red currants Red Red Red Uncolored . rncolorcd . Red Green . Green . Brown . I Deepgn Brown. Hrowu . Brown. Brown. i Brown. ! Brown. •ei . White currants White .... Dark red Yellow Yellow Yellow Yellow Yellow Yellow Black currants Peaches . ... Uncolored . Uncolored . Uncolored . i"n colored. Uncolored. Uncolored. pears (.Quinces \ pples Apricots Green gage plums MJirard and Dupre Analyse des Matieres, etc., p. 167 '•.loiirn. phann. chim., 1901, 13, 174. "Acidity of the juice. 16648— No. 65—02 8 114 PROVISIONAI METHODS FOR ANALYSIS OF FOODS. Extraction of fruit colors ivith amyl-alcohol and with ether. Fruit. Color with NH4OH. Ether ex- tract from acid solution. Amyl-alcohol extract from acid solution. Dyeing tests on the juice. Strawberry . Purple None Red raspberrv Purple None . Deep red Blackberry Cherry Blue-purple .. Purple None Very deep red . Red not dye in the second acid bath. Dyes purplish red in acid solution, but does not dve in the second acid bath. Do Blackberry Blue-purple None Red Do Wild dewberry — Currant Blue-purple . . Blue-purple . . None None Red Red . Do. Do It will be seen from these two tables that amyl-alcohol, as a rule, extracts fruit coloring matter from acid solution, while ether does not. Neither amyl-alcohol nor ether extracted any color from alkaline solution of the fruit juices. 5. DETERMINATION OF ACID MAGENTA — GIRARD'S METHOD.* Add to 100 cc of the solution to be tested 2 cc of potassium hydroxid (5 to 100). If this does not neutralize the acid, add enough to do it. Then add 4 cc of mercuric acetate (10 to 100), agitate and filter. The filtrate should be colorless and slightly alkaline. Acidify with a slight excess of dilute sulphuric acid, and if the solution remains uncolored there is no acid magenta present. If it becomes a light violet-red and there has been no other dye shown by the amyl-alcohol extracts, the presence of acid magenta is shown. Acid magenta in acid solution dyes wool a magenta red. Wool dyed with it is turned yellow by strong hydrochloric acid, decolorized by ammonium hydroxid, and regains its color when washed with water. 6. — TEST FOR MARTIUS YELLOW OR NAPHTHALENE YELLOW. Extract with 95 per cent alcohol from an acidulated sample. Evaporate the alcoholic solution to dryness with a piece of wool, which will be dyed a bright yellow, and test the dyed wool. Both sulphuric and hydrochloric acids completely decolorize it. 7. — ROTA'S METHOD OF IDENTIFICATION OF ORGANIC COLORING MATTER. b The coloring matters are divided into four groups by the use of stannous chlorid and hydrochloric acid and of caustic potash. The reagents are a 10 per cent solution of stannous chlorid and a 20 per cent solu- tion of caustic potash. Dilute the aqueous or alcoholic solution of coloring matter to about 1 to 10,000. This strength is not of vital importance, but the color must not be too deep, as it will mask the reduction in some cases, such as the safranins, where it is slow and not complete. Add to the solution a few drops of stannous chlorid and a few drops of hydrochloric acid; shake, and heat to boiling. Care must be taken to carry along for comparison a solution of the coloring matter acidified with hydrochloric acid, in order not to mistake the action of the acid alone for reduction. Some of the colors — for instance, safranins and indulins — are slow to be reduced and must be allowed to stand for some time. For the stannous chlorid and hydrochloric acid can be substi- tuted a solution of tin in strong hydrochloric acid. •Girard & Dupre, Analyse des Matieres, Alimentaires, etc., p. 169; Winton, Conn. Expt. Sta. Rept., 1899, Pt. II, 132. i>Chem. Ztg., 1898, 22, 437-442; Analyst, 1899, 24, 41. COLORING MATTER. 115 As soon as the group is determined it is possible to carry the work further by refer- ence to tables of coloring matter a in which the physical, chemical, and tinctorial properties are given; but it is impossible for the published books to keep up with the new dyes which are constantly being discovered, so that the tables are never complete, although they will, as a rule, contain all the data necessary. Classification of organic coloring matters. [A portion of the aqueous or alcoholic solution is treated with HC1 and SnCl2.] Complete decolorization. Reducible coloring matters. Colorless solution is treated with Fe«Cl6 or shaken, with exposure to air. The color changed no further than with HC1 alone. Nonreducible colors. A part of origi- nal solution is mixed with 20 per cent KOH and warmed. The liquid remains un- changed. Not reoxi- The original color re- stored. Reoxidizable Decolorization or a pre- cipitate. Imido-carbo- No precipitation. Liquid becomes more colored. dizable coloring mat- coloring matters. quinone coloring mat- Oxy-carbo -quinone ters. ters. coloring matters. CLASS I. CLASS II. CLASS III. CLASS IV. Nitro, nitroso, and azo Indogenide and imido- Amido- derivatives of Nonamide diphenylme- colors, including quinone coloring di and triphenyl-me- thane, oxy-ketone, azoxy and by draco matters, methyl en e thane, auramines, and most of natural colors. blue, safranin, in- acridines, quinolines, organic coloring mat- Picric acid, naphthol digo-carmine. and color derivatives ters. yellow, Ponceau, Bor- of thio benzenil. Fx)sines, aurin, alizarin. deaux, and Congo red. Fuchsin, rosaniline, auramine. •Schultz and Julius, Tabellarische Ubersicht der kiinstlichen organischen Farbstoffe; Allen, Com- mercial Organic Analysis, 3d ed., Vol. Ill, pt. 1, pp. 529-665. 116 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. 11 .B oo V ll V W QJ S 3 ,2 -° I I nig |2J KS •s If .-§! s^l i s^ o3 1? «2 w -i^^ IS IP 85 ^P'l .So c e »j^ s I^S^-S^ '^2'O;2 O.S |p;l+ll !P?l ll! !w COLORING MATTER. 117 g-s II I o § a 1 £ g "2 0) 1 O "0* /°N" 1 "V V ^ "S^ 'V • r ccco I 6g '^6 xi 5 Ss |£ d i I" ! -d 3 8-8 3 S ! Ii 13 N 0) •*3 Sa If 5± HO 1 I| |l §§ -g «• I II * — « if Pli! •3 Sc - — K- O Wl u<>i)h[os oitoqooiw ao snoanbti 118 PROVISIONAL METHODS FOB ANALYSIS OF FOODS. 53i fi £ ?, 5 « HOX uorjnios oiioqoot« ao snoonb COLORING MATTER. 119 8 W « \0/ o ' *a £o 5 -53 2. a -sl -• .2 .s ^ £ *J a a .•e fc .Q 92 tS'o o " si L!|il n wpii •IOH JO SS30X3 uoijnt ^ 18 :s OtS > 60 ^! C -^ Hll rl 15112 8 £5> 2 S "*^" ^ So S •(juaojadi'HOX) 3UTJO[OO 2 . c| ol o' o •(000i:i) ^O^J JO uopnios .ijunp u .1" wl«>jp M jo uo0nt 120 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. 8. — DETERMINATION OF VEGETABLE COLORS. A great many tests for vegetable colors are given, depending largely on color reac- tions with different reagents, but these must be used with very great discrimination, as they depend very largely on a fine judgment of shades of colors which many eyes are not able to distinguish. A great deal of work has been done on detection of vegetable colors, a but only in a very few cases are the reactions specific enough to be decisive. 9. — DETECTION OF TjRMERic.b Extract the color with alcohol. Dip a piece of filter paper into this tincture and dry at 100° C. Then moisten in a weak solution of boric acid to which a few drops of hydrochloric acid have been added. On drying this, a cherry red color will be developed in the presence of turmeric which is characteristic. 10. — DETECTION OF CARAMEL. AMTHOR TEST.C Ten cubic centimeters of the solution to be tested are put into a high, narrow glass with perpendicular sides, as, for example, a small bottle; add from 30 to 50 cc of paraldehyde, depending on the intensity of the coloring, and enough absolute alco- hol to make the solutions mix. In the presence of caramel a brownish yellow to dark-brown precipitate will collect in the bottom of the glass. Decant the liquor, wash once with absolute alcohol, dissolve in small amount of hot water, and filter. The color of this will give some idea as to the amount of caramel present. It is not allowable to concentrate a solution by evaporation on a steam bath, as caramel may be formed; if it is necessary to concentrate it must be done over sul- phuric acid or at diminished pressure. In order to further identify the color it is poured into a freshly prepared solution of phenylhydrazin (2 parts phenylhydrazin-hydrochlorid, 3 parts sodium acetate, and 20 parts of water). The presence of a considerable quantity of caramel gives a dark-brown precipitate in the cold, which is hastened by heating a little. In the case of a very small amount it takes some hours for it to collect. 11. — DETECTION OF COCHINEAL. Cochineal is used to a certain extent as a coloring matter in foods, and a very satis- factory test for it is that given in Girard and Dupre.d Dissolve the food product in water, filtering if necessary. Acidulate with hydrochloric acid and extract with amyl alcohol, which becomes colored more or less yellow or orange, depending on the quantity of cochineal present. Separate the amyl alcohol and wash until neu- tral. Then separate into two portions; to the first add drop by drop a very dilute solution of uranium acetate, shaking thoroughly after each addition. In the pres- ence of cochineal a characteristic emerald-green color is produced.6 To the secor'l portion add a drop or so of ammonia, and in presence of cochineal a violet coloration results. This, however, is not so sensitive to very small amounts as the first tests, and many fruit colors give tests hardly to be distinguished. Cochineal carmine is liable to contain tin, as it is often a tin lake, although alum is also used. It is also liable to adulteration with lead compounds. » Girard and Dupre1, Analyse des Matures Alimentaires, etc., 580-581, also 169; A. W. Blythe, Foods, their Comp. and Anal., p. 91-109; Allen Com. Org. Anal., Vol. Ill, Pt. I; E. Brucher, Fals. Subst Alim., p. 162; W. Lenz, Ztschr. anal. Chem., 1885, 24, 285. i> Allen, Com. Org. Anal., Vol. Ill, Pt. I, p. 359; U.S.Dept.of Agr., Div.of Chem., Bui. 51, p. 131. c Ztsch. anal. Chem., 1885, 24, 30; Borgemann, Anal, des Weines., p. 98. d Analyse des Matieres Alimentaires, etc., p. 580. •The writer has tested this reaction on a number of amyl alcohol extracts from fruits, and in no case was there any chance of mistake in the reaction. Most fruits give a brown color, while black- berries and currants give a bluish color. REFERENCE TABLES. REFERENCE TABLES. TABLE I. — Specific gravity and percentage of alcohol. [According to Squibb.] Per cent alco- hol by vol- ume. Specific gravity. Per cent alco- hol by vol- ume. Specific gravity. Per cenit alco- hol by vol- ume. Specific gravity. At15'56^ 25° At 15756 C" it15-56^ 25° At- P .15-56° t 25° P Al 15. 56 *" At15.56 C' At 15.56°' At15.56 C' Vl 15.56^' 1 0.9985 0. 9970 36 0.9578 0. 9521 71 0.8875 0.87% 2 .9970 .9953 37 .9565 .9507 72 .8850 .8771 3 .9956 .9938 38 .9550 .9489 73 .8825 8746 4 .9942 .9922 39 .9535 .9473 74 .8799 .8719 5 .9930 .9909 40 .9519 .9456 75 .8769 .8689 6 .9914 .9893 41 .9503 .9438 76 .8745 .8665 7 .9898 . 9x7i ; 42 .9490 .9424 77 .8721 .8641 8 .9890 .9868 43 .9470 .9402 78 .8696 .8616 9 .9878 .9855 44 .9452 . 9as-2 79 .8664 .8583 10 .9869 .9846 45 . 9434 . 9363 80 .8639 .8558 11 .9855 .9831 46 .9416 ' .9343 81 .8611 .8530 12 .9841 .9816 47 .9396 . 9323 82 .8581 .8500 13 . 9828 .9801 48 .9381 .9307 83 .8557 .8476 11 .9821 .9793 49 . tfWi'2 . '.I'jss 84 . s.vjt; .8444 15 .9815 .9787 50 .9343 .9267 85 .8496 .8414 16 .9802 .9773 51 .9323 .9246 86 .8466 .8384 17 .9789 . 9759 52 .9303 .9226 87 . 8434 . 8352 18 .9778 .9746 53 .9283 .9205 88 . 8408 . 8326 19 ..0766 .9733 r.i .9262 .9184 89 .8373 j .8291 20 .9760 . 9726 55 .9242 .9164 90 .8340 .8258 21 .9753 .9719 56 .9221 .9143 91 .8305 .8223 22 .9741 .9706 57 .9200 .9122 92 .8272 .8191 23 .9728 .9692 58 .9178 .9100 93 .8237 .8156 24 .9716 .9678 59 .9160 .9081 94 .8199 .8118 25 .9709 .9668 60 .9135 .9056 95 .8164 .8083 26 .9698 .9655 51 .9113 .9034 96 .8125 .8044 27 .9691 .9646 62 .9090 .9011 97 .8084 .8003 28 .9678 .9631 63 .9069 .8989 98 .8041 .7960 29 .9665 .9617 64 .9047 .8969 99 .7995 .7914 30 .9652 .9603 68 .9025 .8947 100 .7946 .7865 31 .9643 .9594 66 .9001 .8923 32 .9631 .9582 67 .8973 .8895 33 .9618 .9567 68 .8949 .8870 34 .9609 .9556 69 .8925 .SSJC, 35 .9593 .9538 70 .8900 .8821 TABLE II. — Percentage of alcohol. [Recalculated from the determinations of Gilpin, Drinkwater, and Squibb.] Alcohol Alcohol Alcohol Specific gravity at|8°F. Per cent by vol- ume. Per cent by weight. Grams per 100 cc. Specific gravitv at|f>F. Per cent by vol- ume. Per cent by weight. Grams per 100 cc. Specific gravity at ;;;;•• K. Per cent by vol- ume. Per cent by weight. Grams per 100 cc. 1.00000 0.00 0.00 0.00 0.99884 0.75 0.60 0.60 0. 99775 .50 1.19 1.19 0. 99992 0.05 0.04 0.04 . 99877 0.80 0.64 0.64 .99768 .55 1.23 1.23 .999H4 0.10 0.08 0.08 . 99869 0.85 0.67 0.67 .99760 .60 1.27 1.27 .99976 0.15 0.12 0.12 .99861 0.90 0.71 0.71 .99753 .65 1.31 1.31 .99968 0.20 0.16 0.16 .99854 0.95 0.75 0.75 .99745 .70 1.35 1.35 .99961 0.25 0.20 0.20 .99849 .00 0.79 0.79 .99738 1.75 1.39 1.39 .99953 0.30 0.24 0.24 .99842 .05 0.83 0.83 .99731 1.80 1.43 1.43 .99945 0.35 0.28 0.28 .99834 .10 0.87 0.87 .99723 1.85 1.47 1.47 .99987 0.40 0.32 0.32 .99827 .15 0.91 0.91 .99716 1.90 1.51 1.51 .99930 0.45 0.36 0.36 .99819 .'JO 0.95 0.95 .99708 1.95 1.55 1.56 . '.wj:', 0.50 0.40 0.40 .99812 .25 0.99 0.99 .99701 2.00 1.59 1.59 .99916 0.55 ii. II i). II .99806 .30 1.03 1.03 . 99694 2.06 1.63 1.62 0.60 I). IS 11. is . '.>'.»7'.I7 . :;:. 1.07 1.07 .99687 2.10 1.67 1.66 .99900 0.65 0.69 0.62 .99790 .40 l.ll 1.11 .99679 2.15 1.71 1.70 .99892 0.70 0.56 0.56 . 99782 . 16 1.15 1.15 .99672 2.20 1.75 1.74 122 PROVISIONAL METHODS FOB ANALYSIS OF FOODS. TABLE II. — Percentage of alcohol — Continued. Alcohol. Alcohol. Alcohol. Specific gravity at|g°F. Per cent by vol- ume. Per cent bv weight. Grains per 100 cc. Specific gravity at|8°F. Per cent by vol- ume. Per cent by weight. Grams per 100 cc. Specific gravity atsrr. Per cent by vol- ume. Per cent by weight. Grams per 100 cc. 0.99665 2.25 .79 .78 0.99215 5.50 4.40 4.37 0. 98807 8.75 7.03 6.95 .99658 2.30 .83 .82 .99208 5.55 4.44 4.40 . 98801 8.80 7.07 6.99 .99651 2.35 .87 .86 . 99202 5.60 4.48 4.44 . 98795 8.85 7.11 7.03 .99643 2.40 .91 .90 . 99195 5.65 4.52 4.48 . 98789 8.90 7.15 7.07 .99636 2.45 .95 .94 . 99189 5.70 4.56 4.52 .98783 8.95 7.19 7.11 .99629 2.50 1.99 1.98 . 99182 5.75 4.60 4.56 . 98777 9.00 7.23 7.14 . 99622 2.55 2.03 2.02 . 99175 5.80 4.64 4.60 .98771 9.05 7.27 7.18 .99615 2.60 2.07 2.06 . 99169 5.85 4.68 4.64 . 98765 9.10 7.31 7.22 .99607 2.65 2.11 2.10 . 99162 5.90 4.72 4.68 .98759 9.15 7.35 7.26 .99600 2.70 2.15 2.14 .99156 5.95 4.76 4.72 .98754 9.20 7.39 7.30 .99593 2.75 2.19 2.18 .99149 6.00 4.80 4.76 . 98748 9.25 7.43 7.34 . 99586 2. HO 2.23 2.22 .99143 6.05 4.84 4.80 . 98742 9.30 7.48 7.38 . 99579 2.85 2.27 2.26 . 99136 6.10 4.88 4.84 . 98736 9.35 7.52 7.42 . 99571 2.90 2.31 2.30 .99130 6.15 4.92 4.88 .98730 9.40 7.56 7.46 . 99564 2.95 2. 35 2.34 .99123 6.20 4.96 4.92 . 98724 9.45 7.60 7.50 . 99557 3.00 2.39 2.38 .99117 6.25 5. 4.96 . 98719 9.50 7.64 7.54 .99550 3.05 2.43 2.42 .99111 6.30 5.05 5.00 . 98713 9.55 7.68 7.58 .99543 3.10 2.47 2.46 .99104 6.35 5.09 5.04 . 98707 9.60 7.72 7.62 .99536 3.15 2.51 2.50 .99098 6.40 5.13 5.08 .98701 9.65 7.76 7.66 . 99529 3.20 2.55 2.54 .99091 6.45 5.17 5.12 . 98695 9.70 7.80 7.70 .99522 3.25 2. 59 2.58 .99085 6.50 5.21 5.16 .98689 9.75 7.84 7.74 . 99515 3.30 2.64 2.62 . 99079 6.55 5.25 5.20 . 98683 9.80 7.88 7.78 .99508 3.35 2.68 2.66 .99072 6.60 5.29 5.24 . 98678 9.85 7.92 7.82 .99501 3.40 2.72 2.70 .99066 6.65 5.33 5.28 . 98672 9.90 7.96 7.85 .99494 3.45 2.76 2.74 .99059 6.70 5.37 5.32 . 98666 '9.95 8.00 7.89 . 99487 3.50 2.80 2.78 .99053 6.75 5.41 5.36 . 98660 10.00 8.04 7.93 . 99480 3.55 2.84 2.82 .99047 6.80 5.45 5.40 .98654 10. 05 8.08 7.97 . 99473 3.60 2.88 2.86 .99040 6.85 5.49 5.44 .98649 • 10.10 8.12 8.01 . 99466 3.65 2.92 2.90 .99034 6.90 5.53 5.48 . 98643 10.15 8.16 8.05 . 99459 3.70 2.96 2.94 .99027 6.95 5.57 5.52 .98637 10.20 8.20 8.09 .99452 3.75 3.00 2.98 .99021 7.00 5.61 5.56 .98632 10.25 8.24 8.13 .99445 3.80 3.04 3.02 .99015 7.05 5.65 5.60 . 98626 10.30 8.29 8.17 .99438 3.85 3.08 3.06 .99009 7.10 5.69 5.64 . 98620 10.35 8.33 8.21 .99431 3.90 3.12 3.10 .99002 7.15 5.73 5.68 . 9S614 10.40 8.37 8.25 . 99424 3.95 3.16 3.14 .98996 7.20 5.77 5.72 . 98609 10.45 8.41 8.29 .99417 4.00 3.20 3.18 .98990 7.25 5.81 5.76 . 98603 10.50 8.45 8.33 .99410 4.05 3.24 3.22 .98984 7.30 5.86 5.80 . 98597 10.55 8.49 8.37 .99403 4.10 3.28 3.26 . 98978 7.35 5.90 5.84 . 98592 10.60 8.53 8.41 . 99397 4.15 3.32 3.30 . 98971 7.40 5.94 5.88 .98586 10.65 8.57 8.45 .99390 4.20 3.36 3.34 .98965 7.45 5.98 5.92 .98580 10.70 8.61 8.49 .99383 4.25 3.40 3.38 .98959 7.50 6.02 5.96 .98575 10.75 8.65 8.53 .99376 4.30 3.44 3.42 . 98953 7.55 6.06 6.00 . 98569 10.80 8.70 8.57 .99369 4.35 3.48 3.46 . 98947 7.60 6.10 6.04 . 98563 10.85 8.74 8.61 .99363 4.40 3.52 3.50 . 98940 7.65 6.14 6.07 . 98557 10.90 8.78 8.65 .99356 4.45 3.56 3.54 . 98934 7.70 6.18 6.11 . 98552 10.95 8.82 8.69 .99349 4.50 3.60 3.58 .98928 7.75 6.22 6.15 .9&546 11.00 8.86 8.73 .99342 4.55 3.64 3.62 .98922 7.80 6.26 6.19 .98540 11.05 8.90 8.77 . 99935 4.60 3.68 3.66 . 98916 7.85 6.30 6.23 . 98535 11.10 8.94 8.81 .99329 4.65 3.72 3.70 .98909 7.90 6.34 6.27 . 98529 11. 15 8.98 8.85 .99322 4.70 3.76 3.74 .98903 7.95 6.38 6.31 . 98524 11.20 9.02 8.89 . 99315 4.75 3.80 3.77 .98897 8.00 6.42 6.35 . 98518 11.25 9.07 8.93 .99308 4.80 3.84 3.81 .98891 8.05 6.46 6.39 . 98513 11.30 9.11 8.97 .99301 4.85 3.88 3.85 .98885 8.10 6.50 6.43 . 98507 11.35 9.15 9.01 . 99295 4.90 3.92 3.89 .98879 8.15 6.54 6.47 .98502 11.40 9.19 9.05 .99288 4.95 3.96 3.93 . 98873 8.20 6.58 6.51 .98496 11.45 9.23 9.09 .99281 5.00 4.00 3.97 . 98867 8.25 6.62 6.55 . 98491 11.50 9.27 9.13 .99274 5.05 4.04 .01 . 98861 8.30 6.67 6.59 . 98485 11.55 9.31 9.17 .99268 5.10 4.08 .05 .98855 8.35 6.71 6.63 .98479 11.60 9.35 9.21 .99261 5.15 4.12 .09 .98849 8.40 6.75 6.67 . 98474 11.65 9.39 9.25 .99255 5.20 4.16 .13 .98843 8.45 6.79 6.71 .98468 11.70 9.43 9.29 .99248 5.25 4.20 .17 .98837 8.50 6.83 6.75 . 98463 11.75 9.47 9.32 . 99241 5.30 4.24 .21 . 98831 8.55 6.87 6.79 .98457 11.80 9.51 9.36 . 99235 5.35 4.28 .25 .98825 8.60 6.91 6.83 . 98452 11.85 9.55 9.40 .99228 5.40 4.32 .29 .98819 8.65 6.95 6.87 .98446 11.90 9.59 9.44 .99222 5.45 4.36 4.33 . 98813 8.70 6.99 6.91 . 98441 11.95 9.63 9.48 REFERENCE TABLES. 123 TABLE II.— Percentage of alcohol— Continued. Specific gravity «M°P. Alcohol. Specific gravity at|g0F Alcohol. Specific gravity at§§°F. Alcohol. Per cent by vol- ume. Per cent by weight Grams per 100 cc. Per cent by vol- ume. Per cent by weight Grams per 100 cc. Per cent by vol- ume. Per cent by weight Grams per 100 cc. 0.98435 12.00 9.67 9.52 0.98088 15.25 12.33 12.10 0. 97758 18.50 15.02 14.68 .98430 12. 05 9.71 9. 56 .980X3 15.30 12.38 12. 14 . 97753 18.55 15.06 14. 72 .98424 12.10 9.75 9.60 . 9X07X 15. 35 12. 42 12.18 . 97748 18.60 15.10 14.76 .98419 12.15 9.79 9.64 .98073 15.40 12.46 12.22 .97743 18.65 15.14 14.80 .98413 12. 20 9.83 9.68 .98068 15.45 12.50 12.26 .97738 18.70 15.18 14.84 .98408 12.25 9.87 9.72 .98063 15.50 12.54 12.30 .97733 18.75 15. 22 14.88 .98402 12.30 9.92 9.76 . 98057 15.55 12.58 12.34 . 97728 18.80 15.27 14.92 . 98397 12.35 9.96 9.80 . 98052 15.60 12.62 12. 37 .97723 18.85 1 15.31 14.96 . 98391 12.40 10.00 9.84 .98047 15.65 12.66 12. 41 . 97718 18. 90 15. 38 15.00 .98386 12.45 10.04 '.). ss .98042 15.70 12.70 12.45 .97713 18.95 15.39 15.04 .98381 12.50 10.08 9.92 .98037 15.75 12.75 12.49 .97708 19.00 15.43 15.08 .98375 12.50 10.12 9.96 .98032 15.80 12.79 12.53 .97703 19.05 15.47 15.11 .98870 12.60 10.16 10.00 .98026 15.85 12. 83 12. 57 .97698 19.10 15.51 15. 15 .98364 12. 65 10.20 10.03 .98021 15.90 12. S7 12.61 . 97693 19. 15 15.55 15.19 .98359 12.70 10.24 10.07 .98016 15.95 12.91 12. 65 .97688 19. 20 15. 59 16.28 .98353 12.75 10.28 10.11 .98011 16.00 12.95 12. 69 .97683 19.25 15.63 15.27 .98348 12.80 10.33 10.15 .98005 16.05 12.99 12. 73 .97678 19.30 15.68 15.31 .98342 12. 85 10.37 10.19 .98001 16.10 13.03 12.77 . 97673 19.35 15.72 15.35 .98337 12.90 10.41 10.23 .97996 16.15 13.08 12. 81 .97668 19.40 15.76 15.39 .98331 12.95 10.45 10.27 .97991 16. 20 13.12 12.85 .97663 19.45 15.80 15.43 .98326 13.00 10.49 10.31 .97986 16.25 13.16 12.89 .97658 19.50 15.84 15.47 .98321 13. 05 10. 53 10. 35 .97980 16.30 13.20 12.93 .97653 19.55 15.88 15. 51 . 98315 13.10 10.57 10.39 . 97975 16.35 13.24 12.97 .97648 19.60 15.93 15.55 .98310 13.15 10.61 10. 43 . 97970 16.40 13.29 13.01 .97643 19.65 15.97 15.59 . 98305 13.20 10.65 10. 17 .97965 Hi. i:, 13.33 13.05 .97638 19.70 16.01 16.63 . 98299 13.25 10.69 10.51 .97960 16.50 13.37 13.09 .97633 19.75 16.05 15.67 .96294 13.30 10.74 10. 55 . 97955 16.55 13.41 13.13 .97628 19.80 16.09 15.71 . 98289 13.35 10.78 10.59 .97960 16.60 13. 45 13.17 .97623 19.85 16.14 15.75 .98283 13.40 10.82 10.63 . 97945 16.65 13.49 13.21 . 97618 19.90 16.18 15.79 . 98278 13.45 10.86 10.67 . 97940 16.70 13.53 13.25 .97613 19.95 16.22 15.83 .98273 13.50 10.90 10.71 . 9.7935 16. 75 13.57 13.29 .97608 20.00 16.26 15.87 . 98267 13. 55 10.94 10. 75 .97929 16.80 13. 62 13.33 .97603 20.05 16.30 15. 91 .98262 13.60 10.98 10.79 . 97924 16.8)5 13.66 13.37 . 97598 20.10 16.34 15. 95 . 98256 13. 65 11.02 10.83 . 97919 16.90 13.70 13.41 . 97593 20.15 16.38 15.99 .98251 13.70 11.06 10.87 .97914 16.95 13.74 13.45 .97588 20.20 16.42 16.03 . 98246 13. 75 11.11 10.91 .97909 17.00 13.78 13.49 .97583 20.25 16.46 16.06 .98240 13.80 11.15 10. 95 .97904 17. 05 L8.82 13.53 . «.»7.-.7x 20.30 16.51 16.10 .98235 18,85 11.19 10.99 . '.I7SW 17.10 13.86 13.57 . 97573 20.35 16.58 16.14 .98230 18.90 11.28 11.03 .97894 L7.15 13.90 13.61 .97568 20.40 16.59 16.18 .98224 13. 95 11,27 11.07 .97889 17.2(1 13.94 13.65 . 97503 20.45 16.63 16.22 . 98219 14.00 11.31 11.11 .97884 17.26 13.98 13.69 .975,58 20.50 16.67 16.26 . 98214 14.05 11.35 11. 15 . (.>7S7'.» 17.30 14.03 13.73 . U75.VJ 20. 55 16.71 16.30 .98209 14.10 11.39 11.19 . t)7S7 1 17.:;:. 14.07 13.77 .97547 20.60 16.75 16.34 . US203 14.16 11.43 ilia . 97869 17.40 14.11 13.81 . 97542 20.65 16.80 16.38 .98198 14.20 11. 17 11.27 .97864 17. 15 14.15 13.85 . 97537 20.70' 16.84 16.42 .98193 14.25 11.52 11.31 .97859 17.50 14.19 13.89 .97532 20.75 16.88 16.46 .98188 14.30 11.56 11.35 . '.17 v.:; 17.65 14. 23 13.92 . 97527 20.80 16.92 16.50 . 98182 14. 35 11.60 11.39 .97848 17. CO 14. 27 13.96 .97522 20.85 16.96 16.54 .98177 14.40 11.64 11.43 .97843 17.65 14.31 14.00 .97517 20.90 17.01 16.58 . 9X172 14.45 11.68 11.47 .97888 17.70 14.35 14.04 .97512 20. 95 17.05 16.62 . 98167 14.50 11.72 11.51 .97833 17.75 14.40 14.08 .97507 21.00 17.09 16.66 .98161 14.55 11.76 1 1 . 55 . '.J7.VJS 17.80 It. 11 14.12 .97502 21.05 17.13 16.70 . 98156 14.60 11.80 11.59 .97823 17.85 14.48 14.16 . 97497 21.10 17.17 16.74 .98161 14.65 11.84 11.63 . 97818 17.90 14.62 14.20 . 97492 21.16 17. 22 16.78 . 98146 14.70 11.88 11.67 .97813 17.95 14.56 14.24 .97487 21.20 17.26 16.82 .98140 14.75 11.93 11.71 .97808 18.00 14.60 24.28 . 97482 21.25 17.30 16.86 .98135 | 14.80 11.97 11.76 .97803 18.05 14.64 14.32 .97477 21.30 17.34 16.90 .98130 H.s;, 12. 01 11.79 .97798 18.10 14.68 14.36 . 97472 21.35 17.38 16.94 .9~8125 11. IK) 12.05 11.82 . 977l« 18.15 14.73 14.40 . '.»74«57 21.40 17.43 16.98 .98119 14.95 12.09 11.86 . '.I77SS L8.20 14.77 14.44 . 97462 21.46 17.47 17.02 .98114 15.00 12.13 11.90 .97783 18.25 14. si 14.48 . 97457 21.50 17.51 17.06 .96108 15.05 12.17 11.94 . '.1777* 18.30 14.85 14.52 .97451 21.55 17.55 17.10 .98104 15.K) 12.21 11.98 .11777:; 18.86 14.89 14.56 . (.»7 1 1C, 21. 60 17.59 17.14 .98099 15. i:> 12. 25 12.02 . '.»77i;s IS. 10 14.94 14.60 . '.17 1 1 1 21.65 17.63 17.18 .98093 15. 20 12.29 12. 06 .97763 18.45 14.98 14.64 .97436 21.70 17.67 17.22 124 PRO VISIONAL METHODS FOR ANALYSIS OF FOODS. TABLE II. — Percentage of alcohol — Continued. Specific gravity at;;:;°F. Alcohol. Specific gravity at|g°F. Alcohol. Specific gravity at|g°F. Alcohol. Per cent by vol- ume. Per cent by weight. Grams per 100 cc. Per cent by vol- ume. Per cent by weight. Grams per 100 cc. Per cent by vol- ume. Per cent by weight. Grams per 100 cc. 0. 97431 21.75 17.71 17.26 0. 97097 25. 00 20. 13 19.84 0. 96744 28.25 23.17 22.42 . 97426 21. 80 17.76 17.30 . 97092 25. 05 20. 47 19.88 .96738 28. 30 23. 21 22.45 . 97421 21.85 17.80 17.34 . 97086 25. 10 20. 51 19.92 . 96732 28.35 23.25 22. 49 . 97416 21.90 17.84 17.38 . 97081 25.15 1 20.56 19.96 . 96726 28.40 23.30 22.53 . 97411 21.95 17.88 17.42 . 97076 25.20 20. 60 20.00 . 96721 28.45 23.34 22.57 .97406 22. 00 17.92 17.46 . 97071 25.25 20.64 20.04 . 96715 28.50 23.38 22 fil . 97401 22.05 17.96 17.50 .97065 25.30 20.68 20.08 . 96709 28.55 23.42 ! 22.65 . 97396 22.10 18.00 17. 54 .97060 25.35 20. 72 20. 12 . 96704 28.60 23.47 22 6Q . 97391 22.15 18.05 17.58 . 97055 25. 40 20. 77 20.16 .96698 28.65 23.51 22.73 .97386 22.20 18.09 17.62 .97049 25.45 20.81 20.20 .96692 28.70 23.55 22.77 . 97381 22.25 18.13 17.66 .97044 25.50 20.85 20.24 .96687 28.75 23.60 22.81 .97375 22.30 18.17 17.70 .97039 25.55 20. 89 20. 28 .96681 28.80 •-':;. HI 22. 85 . 97370 22.35 18.21 17.74 . 97033 25.60 20.93 20.32 .96675 28.85 23. 68 22. 89 .97366 22.40 18.26 17.7s .97028 25.65 20.98 20.36 .96669 28.90 23. 72 22. 93 .97360 22.45 18.30 17.82 .97023 25.70 21.02 20.40 .96664 28.95 23.77 22.97 .97355 22.50 18.34 17.86 . 97018 25.75 21.06 20.44 .96658 29.00 23.81 23.01 .97350 22.55 18.38 17.90 . 97012 25.80 21. 10 20.47 .96652 29.05 23.85 23.05 .97345 22.60 18.42 17.94 .97007 25.85 21.14 20. 51 .96646 29. 10 23.89 23.09 .97340 22.65 18.47 17.98 .97001 25.90 21.19 20.55 .96640 29. 15 23.94 23.13 .97335 22.70 18.51 18.02 .96996 25.95 21. 23 20.59 .96635 29.20 23.98 23.17 . 97330 22.75 18.55 18.06 . 96991 26.00 21.27 20.63 .96629 29.25 24.02 23.21 . 97324 22.80 18.59 18.10 .96986 26.05 21.31 20. 67 .96623 29.30 24. 06 23.25 . 97319 t85 18.63 18.14 .96980 26. 10 21.35 20.71 .96617 29. 35 24.10 23.29 . 97314 90 18.68 18.18 .96975 26.15 21.40 20. 75 . 96611 29. 40 24.15 23.33 . 97309 22.95 18.72 18.22 .96969 26.20 21.44 20.79 .96605 29.45 24.19 23.37 .97304 23.00 18.76 18.26 .96964 26.25 21.48 20.83 .96600 29.50 24.23 23.41 . 97299 23. 05 18.80 18.29 . 96959 26.30 21. 52 20.87 .96594 29.55 24.27 23. 4r> . 97294 23.10 18.84 18. 33 .96953 26.35 21.56 20.91 .96587 29.60 24. 32 23.49 . 97289 23.15 18.88 18.37 .96949 26.40 21.61 20. 95 .96582 29.65 24.36 23. 53 .97283 23.20 18.92 18.41 .96942 26. 45 21.65 20.99 .96576 29.70 24.40 23.57 . 97278 23.25 18.96 18.45 .96937 26.50 21.69 21.03 . 96570 29.75 24.45 23.61 . 97273 23.30 19.01 18.49 . 96932 26.55 21.73 21.07 .96564 29.80 24.49 23.65 .97268 23.35 19.05 18.53 . 96926 26.60 21.77 21.11 .96559 29.85 24.53 23.69 . 97263 23.40 19.09 18.57 .96921 26.65 21.82 21.15 .96553 29.90 24.57 23.73 . 97258 23.45 19.13 18.61 .96915 26.70 21.86 21.19 .96547 29.95 24.62 23.77 .97253 23.50 19.17 18.65 .96910 26.75 21.90 21.23 .96541 30.00 24.66 23.81 . 97247 23.55 19.21 18.69 .96905 26.80 21.94 21.27 .96535 30.05 24.70 23.85 . 97242 23.60 19:25 18.73 .96899 26.85 21.98 21.31 .96529 1 30.10 24.74 23.89 . 97237 23.65 19.30 18.77 .96894 26.90 22.03 21.35 .96523 30.15 24.79 23.93 . 97232 23.70 19.34 18.81 .96888 26. 95 22.07 21.39 .96517 30.20 24.83 23.97 .97227 23.75 19.38 18.84 .96883 27.00 22.11 21.43 .96511 30.25 24.87 24.01 . 97222 23.80 19. 42 18.88 .96877 27.05 22.15 21.47 .96505 30.30 24. 91 24.04 . 97216 23.85 19.46 18.92 . 96872 27.10 22.20 21.51 . 96499 30.35 24.95 24.08 . 97211 23. 90 . 19.51 18.96 .96866 27.15 22.24 21.55 .96493 30.40 25.00 24.12 .97206 23.95 19.55 19.00 .96861 27.20 22.28 21.59 .96487 30.45 25.04 24.16 .97201 24.00 19.59 19.04 .96855 27.25 22.33 21.63 . 96181 30.50 25.08 24.20 .97196 24. 05 19.63 19.08 .96850 27.30 22.37 21.67 . 96475 30.55 25.12 24.24 .97191 24.10 19.67 19. 12 .96844 27.35 22.41 21.71 .96469 30.60 25.17 24.28 .97185 24. 15 19.72 19.16 .96839 27.40 22.45 21.75 .96463 30.65 25. 21 24.32 .97180 24.20 19.76 19.20 .96833 27.45 22.50 21.79 .96457 30.70 25.25 24.36 .97175 24.25 19.80 19.24 .96828 27.50 22.54 21.83 .96451 30.75 25.30 24.40 .97170 24.30 19.84 19.28 .96822 27.55 22.58 21.86 .96445 30.80 25.34 24. 44 .97165 24.35 19.88 19.32 .96816 27.60 22.62 21.90 .96439 30.85 25.38 24.48 .97159 24.40 19.93 19.36 .96811 27.65 22. 67 21.94 .96433 30.90 25.42 24. 52 .97154 24.45 19.97 19.40 .96805 27.70 22.71 21.98 .96427 30.95 25.47 24.56 . 97149 24.50 20.01 19.44 .96800 27.75 22.75 22.02 . 96421 31.00 25.51 24.60 . 97144 24.55 20. 05 19.48 .96794 27.80 22.79 22.06 . 96415 31.05 25.55 24.64 . 97139 24.60 20.09 19. 52 .96789 27. 85 22.83 22.10 . 96409 31.10 25.60 24. 68 .97133 24. 65 20.14 19.56 . 96783 27.90 22.88 22.14 .96403 31.15 25. 64 24. 72 .97128 24.70 20.18 19.60 .96778 27. 95 22.92 22.18 .96396 31.20 25.68 24.76 . 97123 24. 75 20.22 19.64 . 96772 28.00 22.96 22.22 .96390 31.25 25. 73 24. 80 .97118 24.80 20.26 19.68 . 96766 28.05 23.00 22. 26 .96384 31.30 25.77 24.84 . 97113 24. 85 20.30 19.72 .96761 28. 10 23. 04 22.30 . 96378 31.35 25. 81 24.88 .'.17107 24.90 20. 35 19.76 .96755 28.15 23.09 22.34 .96372 31.40 25.85 24.92 . 97102 24. 95 20.39 19.80 .96749 28. 2C 23.13 22.38 .96366 31.45 25.90 24.96 REFERENCE TABLES. 125 TABLE II. — Percentage <>f lt<>/ — Continued. Specific gravity at |8° F. Alcohol. Specific gravity at|8°F. Alcohol. Specific gravity at§8°F. Alcohol. Per cent by vol- ume. Per cent by weight. tirains per 100 cc. Per cent by vol- ume. Per cent by weight. Grams per 100 cc. Per cent, by vol- ume. Per cent by weight. Grams per 100 cc. o. %:;t;o 31.50 25. 94 25.00 0.95943 34.75 2S. 7 1 27.58 0. 95487 38.00 31.58 30.16 .96368 81.65 25. '.»s 25. 0-1 . 95937 34.80 2s. 7s 27.62 .95480 38. 05 81.63 30.20 .96347 31.tiO 26.03 25. 08 . 95930 84.86 28.83 27.66 . 95472 38.10 31.67 30.24 .96341 31.65 26.07 25. 12 . '.•:>'. fj:; 34.90 28.87 27.70 .95465 38.15 31.72 30.28 . %335 31 70 26.11 25. 16 .95917 34.95 28.92 27. 74 .95457 38.20 31.76 30. 32 . 96329 31.75 26.16 25. 20 .95910 35.00 28.96 27. 78 .95450 38.25 31. SI 30.36 .96323 31.80 26.20 25. 21 . 95903 35. 05 29.00 27. S2 .95442 38.30 81.86 30.40 . IMWN5 31.85 •2(5. 24 25.28 .95896 35.10 29. 05 27.86 .96435 88.86 31.90 30.44 . 96310 31.90 26. 28 •25. 32 .95889 &5.15 29.09 27.90 .95427 38.40 31. '.U 30.48 .96304 31.95 26.33 25.36 .95883 35.20 29.13 27.94 .95420 38.45 31.99 30.52 .96298 32.00 2«. 37 25.40 .95876 35.25 29. 18 27. UN .95413 38.50 32. 03 30.56 . W2'.»2 32. 05 26.41 25. 44 . 95869 35.30 29.22 28.02 .95405 38.55 32. 07 30.60 .96285 32. 10 26. 16 25. is .96862 35.35 29.26 28.05 .95398 38.60 32.12 80.64 . %27'.» 32.15 26.60 25. 52 . H5S55 35.40 29.30 28.09 .95390 38.65 32. 16 30.68 .%273 32. 20 20. 54 25. 56 .95848 35.45 29.35 28.13 .95383 38.70 32.20 30.72 .96267 32. 25 26.59 25.60 .9.5842 35.50 29.30 28.17 .95375 38.75 32. 25 30.76 .96260 152. 30 26.63 26.64 . '.15*35 35.55 29.43 28.21 .96868 38.80 32.29 30.79 .96254 32.86 26. 67 25.68 . «.»5N2s 35.60 29.48 28.25 .95360 32.33 80.83 . 96248 32. 40 26.71 26.71 . 95821 35.65 29.52 28.29 . '..5353 38.90 32.37 30.87 . 96241 32.45 26.76 25. 75 .95814 35.70 29.57 28.33 . 95345 38.95 32.42 30.91 .96235 32. 50 26. 80 25.79 .95807 K, 75 29.61 28.37 .95338 39.00 32.46 30.95 .96229 26.84 25. Ki .96800 85.80 29.65 28.41 .95330 39. 05 32.50 30.99 . 96222 32.60 j 26.89 25. 87 . '.C>7'.» 1 35.85 29.70 28.45 .95323 39.10 3-1 55 31.03 .96216 32.65 26.93 26.91 .95787 35.90 29.74 28.49 .96815 39. 15 32. 59 31.07 .96210 32.70 26.97 25.95 .95780 35.95 29. 79 28.53 .95307 39:20 32.64 31.11 .96204 32.75 27.02 25.99 . 95773 36.00 29.83 28.57 .95300 39.25 31.14 .96197 32.80 27.06 26. 03 .95766 36.05 29.87 28.61 . '.I52-.I2 39.30 32. 72 31.18 .96191 32.85 27.10 26.07 . 95759 36.10 29.92 2V (55 .95284 39.35 32. 77 31.22 .96185 32.90 27.14 26. 1 1 .95752 36.15 29.96 2S. r,'.. . «.»5277 39.40 :;•_'. si 81.26 .96178 32.95 27.19 26.15 .95745 36.20 30.00 28.73 .95269 39.45 32.86 31.30 .96172 33.00 27.23 26.1'.» .95738 36.25 30.05 28.77 .95262 39.50 32.90 31.34 .96166 33. 05 27. 27 2(i. 23 .95731 36.30 30.09 28.81 .95254 39.55 32.95 81.88 .96169 SI. 10 27.32 2(5. 27 . 1»572 1 36.35 30.13 2S.M .96246 39.60 32.99 81. 12 .96168 33. 15 27. 36 26.31 . 95717 36.40 30.17 28.88 . 95239 39.65 33.04 31.46 . 96146 33.20 27.40 26.35 . 95710 36. 15 30.22 28.92 .95231 39.70 33.08 31.50 .96140 33.25 27.45 26.39 . 95703 36.50 30.26 2S. '.16 .95223 39.75 33.13 31.54 .96188 33.30 27.49 26.43 .96696 36. 55 80.80 29.00 .95216 39.80 33. 17 31.58 .96127 33. 35 27. 53 2»i. 17 36. 60 80.85 29.04 .95208 39.85 33.22 31.62 .96120 33. 40 27. 57 26. 51 .96681 36. 65 30.39 29.08 .95200 39.90 88.27 31.66 .96114 33.45 27.62 26.55 . 95674 86.70 30.44 •_".'.!_' .95193 39.95 33.31 31.70 .96108 33. 50 27. 66 26. 59 .'.15667 36.75 30.48 29.16 .95185 40.00 33.35 31.74 .96101 33. 55 27. 70 26. (53 .'.156(10 36.80 30.52 29.20 196177 40.05 33.39 31.78 . 96095 33. 60 27. 75 2(5. 67 .96668 30.57 •_".!. 2 1 . 95169 40.10 :•::;. 1 1 81.82 .96088 33.65 27. 79 86.71 .96646 86.90 30.61 •J'.). I".' .95161 40. 15 33. IS 31.86 .96082 33. 70 27.83 215. 7:. . 95639 36.95 30,66 29.32 .95154 40.20 33.53 31.90 .96075 33.75 27.88 26.79 .95632 37.00 30.70 •_".». 36 .96146 40.25 33.57 31.94 .96069 83.80 27.92 2(5. S2 .96625 87.06 30. 7 1 29.40 .95138 40.30 33.61 31.98 .96062 83. 85 27.96 26.86 .95618 87.10 30.79 •_".». 1 1 .96180 40.35 33.66 32.02 .96056 33.90 28.00 26.90 .95610 87.16 30. S3 •J'.i. is .95122 40.40 33.70 32.06 .96049 88.96 28.05 26.94 .95603 37.20 30.88 •-".'. 52 . 95114 40.45 33.75 32. 10 .96043 84.00 28.09 26.98 .955% 37. 25 30.92 29. 56 .95107 40.50 33.79 32.14 .96036 84.06 2S. 13 27.02 . '.»55S'.t 37. :;o 30.96 29.60 .95099 40.55 33.84 32.18 .96030 34. 10 28. 18 27.06 .96681 37. 35 31.01 29.64 .95091 40.60 33.88 32. 22 .915023 34. 15 2S. 22 27.10 . 9667 1 37. Ill 31.05 •J'.t. 6S .95083 40.65 33.93 32.26 .96016 34. 20 2S. 26 27. 1 1 .95567 37. 15 31.10 29.72 .95075 40.70 33.97 32.30 .96010 34.25 28.31 27. 18 .95560 37.50 31.11 29.76 . 95067 40.75 34. 02 32.34 .96003 84.30 2S.35 27. 22 . H5552 37. 55 31.18 29.80 . 95059 40.80 34.06 32.38 . 95996 34.35 2.s. 3'.i 27. 26 37.60 31.23 29.84 . 95052 40.85 34.11 32.42 .96090 34.40 2s. 13 27.30 . D553S 37. f,5 31 . 27 29.88 .96044 40.90 34.15 32. 16 . U5'.)S3 34.45 28.48 27.34 .95531 37.70 31.32 29.92 .95036 40.95 34.20 82.60 . '.i.V.177 14.60 2S. 52 27. 3s .96628 37. 75 81.88 29.96 .95028 41.00 34.24 .96970 2S. f)6 27. 42 .'.(5516 :;:.sn 31.40 30.00 .95020 41.06 84.28 . '.I.V.M;:; 84.60 28.61 '11. 46 .'.»550<> 87.88 31. 15 30.01 .95012 41.10 34.33 32. (J2 . '.I5-.I57 84.66 2S. I',:, 27. 50 37. '.»<) 81.49 80.08 .95004 41. 15 84.87 32. M 84.70 28.70 27.54 .95494 37. 95 31.. M 30.12 .94996 41.20 34.42 3'J. 70 126 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. TABLE II. — Percentage of alcohol — Continued. Specific gravity ati§°F. Alcohol. Specific gravity at |g° F. Alcohol. Specific gravity at |g° F. Alcohol. Per cent by vol- ume. Per cent by weight. Grams per 100 cc. Per cent by vol- ume. Per cent by weight. Grams per 100 cc. Per cent by vol- ume. Per cent by weight. Grams per 100 cc. 0. 94988 41.25 34.46 32. 74 0. 94493 44.25 37.16 35.11 0. 93962 47.25 39.90 37.49 . 94980 41.30 34.50 32.78 . 94484 44.30 37.21 35.15 . 93953 47.30 39.95 37.53 .94972 41.35 34.55 32. 82 . 94476 •44. 35 37.25 35.19 . 93944 47.35 39.99 37.57 . 94964 41.40 34. 59 32.86 .94467 44.40 37.30 35.23 . 93934 47.40 40.04 37.61 . 94956 41.45 34.64 32.90 .94459 44.45 37.34 35.27 . 93925 47.45 40.08 37.65 . 94948 41.50 34.68 32.93 .94450 44.50 37.39 35.31 . 93916 47.50 40.13 37.69 . 94940 41.55 34.73 32.97 . 94441 44.55 37.44 35.35 . 93906 47.55 40.18 j 37.73 . 94932 41.60 34.77 33.01 . 94433 44.60 37.48 35.39 .93898 47.60 40.22 37.77 .94924 41.65 34.82 33.05 . 94424 44.65 37. 53 35.43 .93888 47.65 40.27 37.81 . 94916 41.70 34.86 33.09 . 94416 44.70 37.57 35.47 . 93879 47.70 40.32 37.85 . 94908 41.75 34.91 33.13 . 94407 44.75 37.62 35.51 . 93870 47.75 40.37 37.89 .94900 41.80 34.95 33.17 .94398 44.80 37.66 35.55 . 93861 47.80 40.41 37.93 . 94892 41.85 35.00 33.21 .94390 44.85 37. 71 35.59 . 93852 47.85 40.46 37.97 . 94884 41.90 35.04 33.25 .94381 44.90 37.76 35.63 . 93842 47.90 40.51 38.01 .94876 41.95 35.09 33.29 . 94373 44.95 37.80 35.67 .93833 47.95 40. 55 38.05 . 94868 42.00 35.13 33.33 .94364 45.00 37. 84 35.71 . 93824 48.00 40.60 38.09 .94860 42.05 35.18 33.37 . 94355 45.05 37.89 35.75 . 93815 48.05 40.65 38.13 . 94Sfi2 42.10 35.22 33.41 . 94346 45.10 37.93 35.79 . 93805 48.10 40.69 38.17 .94843 42.15 35.27 33.45 . 94338 45.15 37.98 35.83 .93796 48. 15 40.74 38.21 . 94835 42.20 35.31 33.49 . 94329 45.20 38.02 35.87 . 93786 48.20 40.78 38.25 . 94827 42. 25 35.36 33.53 . 94320 45.25 38.07 35.91 . 93777 48.25 40.83 38.29 . 94810 42. 30 35.40 33.57 . 94311 45. 30 38. 12 35.95 .93768 48.30 40.88 38.33 .94811 42.35 35.45 33.61 . 94302 45.35 38.16 35.99 . 93758 48.35 40.92 38.37 .94802 42.40 35.49 33.65 .94294 45. 40 38.21 36. 03 . 93749 48.40 40.97 38.41 . 94794 42.45 35.54 33.69 .94285 4o.45 38.25 36.07 . 93739 48.45 41.01 38.45 .94786 42.50 35. 58 33.73 .94276 45.50 38.30 36.11 . 93730 48.50 41.06 38.49 . 94778 42.55 35.63 33.77 .94267 45.55 38.35 36. 15 . 93721 48.55 41.11 38.53 . 94770 42.60 35.67 33.81 . 94258 45.60 38.39 36.19 . 93711 48.60 41. 15 38.57 .94761 42.65 35.72 33.85 .94250 45.65 38.44 36.23 . 93702 4S. 65 41. 20 38. 61 . 94753 42.70 35.76 33.89 .94241 45.70 38.48 36.26 . 93692 48.70 41.24 38.65 . 94745 42.75 35.81 33.93 .94232 45. 75 38.53 36.30 .93683 48.75 41.29 38.68 . 94737 42.80 35.85 33.97 .94223 45.80 38. 57 36.34 . 93679 48.80 41.34 38.72 . 94729 42.85 35.90 34.00 .94214 45.85 38.62 36.38 . 93664 48.85 41.38 38.76 . 94720 42.90 35.94 34.04 .94206 45.90 38.66 36.42 . 93655 48.90 41.43 38.80 . 94712 42.95 35.99 34.08 .94197 45.95 38.71 36.46 . 93645 48.95 41.47 38.84 .94704 43.00 36.03 34.12 .94188 46.00 38.75 36.50 . 93636 49.00 41.52 38.88 . 94696 43. 05 36.08 34.16 . 94179 46.05 38.80 36.54 . 93626 49.05 41.57 38.92 .94687 43.10 36. 12 34.20 .94170 46.10 38.84 36.58 . 93617 49.10 41.61 38.96 . 94679 43. 15 36.17 34.24 . 94161 46.15 38.89 36.62 . 93607 49.15 41.66 39.00 . 94670 43.20 36.21 34.28 . 94152 46.20 38.93 36.66 . 93598 49.20 41.71 39.04 .94662 43.25 36.23 34.32 . 94143 46.25 38.98 36.70 . 93588 49.25 41.76 39.08 .94654 43.30 36.30 34. 36 . 94134 46.30 39.03 36.74 .93578 49.30 41.80 39. 12 .94645 43. 35 36.35 34.40 . 94125 46.35 39.07 36.78 .93569 49.35 41.85 39.16 .94637 43.40 36.39 34.44 . 94116 46.40 39. 12 36.82 . 93559 49.40 41.90 39.20 .94628 43.45 36.44 34.48 . 94107 46.45 39.16 36.86 .93550 49.45 41.94 39.24 . 94620 43.50 36.48 34. 52 .94098 46.50 39.21 36.90 . 93.540 49.50 41.99 39.28 .94612 43.55 36.53 34.56 . 94089 46.55 39.26 36.94 . 93530 49.55 42.04 39.32 . 94603 43.60 36.57 34.60 . 94080 46.60 39.30 36.98 .93521 49.60 42.08 39.36 .94595 43. 65 36.62 34.64 . 94071 46.65 39.35 37.02 .93511 49.65 42. 13 39.40 .94586 43.70 36.66 34.68 . 94062 46.70 39.39 37.06 .93502 49.70 42.18 39.44 . 94578 43.75 36.71 34.72 .94053 46.75 39.44 37.09 .93492 49.75 42. 23 39.48 . 94570 43.80 36.75 34.76 ! .94044 46.80 39.49 37.13 . 93482 49.80 42.27 39.52 .94561 43.85 36.80 34.80 . 94035 46.85 39.53 37.17 .93473 49.85 42. 32 39.56 . 94553 43.90 36.84 34.84 .94026 46.90 39.58 37.21 . 93463 49.90 42. 37 39.60 .94544 43.95 36.89 34.88 .94017 46.95 39.62 37.25 .93454 49.95 42.41 39.63 .94536 44.00 36.93 34.91 .94008 47.00 39.67 37.29 .94527 44.05 36.98 34.95 .93999 47. 05 39. 72 37.33 . 94519 44.10 37. 02 34. 99 .93990 47.10 39.76 37.37 . 94510 44.15 37.07 35.03 . 93980 47. 15 39.81 37.41 .94502 44.20 37.11 35. 07 . 93971 47.20 39.85 37.45 REFERENCE TABLES. 127 TABLE III. — Extract in beer wort. a [According to Schultz and Ostermann.] Specific gravity at!5°C. Extract. Specific gravity at!5°C. Extract. Specific gravity at!5°C. Extract. Specific gravity at!5°C. Extract. Per cent by weight. Grams per 100 cc. Per cent by weight. Grams per 100 cc. Per cent by weight. Grams per 100 cc. Per cent by weight. Grams per 100 cc. 1.0000 0.00 0.00 1.0065 1.69 1.70 1. 0130 3.35 3.39 1. 0195 5.06 5.16 1.0001 0.03 0.03 1.0066 1.72 1.73 1.0131 3.38 3.42 1.0196 5.09 5.19 1.0002 0.05 0.05 1.0067 1.74 1.75 1. 0132 3.41 3.46 1.0197 5.12 5.22 .1.0003 0.08 0.08 1.0068 1.77 1.78 1.0133 3.43 3.48 1.0198 5.15 5.25 1.0004 0.10 1.10 1.0069 1.79 1.80 1. 0134 3.46 3.51 1.0199 5.17 5.27 1. 0005 0.13 0.13 1.0070 1.82 1.83 1. 0135 3.48 3.53 1.0200 5.20 5.30 1.0006 0.16 0.16 1.0071 1.84 1.85 1.0136 3.51 3.56 1.0201 5.23 5.34 1.0007 0.18 0.18 1.0072 1.87 1.88 1. 0127 3.54 3.59 1.0202 5.25 5.36 1.0008 0.21 0.21 1.0073 1.90 1.91 1.0138 3.56 3.61 1.0203 5.28 5.39 1.0009 0.24 0.24 1.0074 1.92 1.93 1.0139 3.59 3.64 1.0204 5.30 5.41 1.0010 0. 26 0.26 1.0075 1.95 ! . % 1.0140 3.61 3.66 1.0205 5.33 5.44 1.0011 0.29 0.29 1.0076 1.97 1 . '.»s 1.0141 3.64 3.69 1.0206 5.35 5.46 1.0012 0.31 0.31 1.0077 2.00 2.02 1.0142 3.66 3.71 1.0207 5.38 5.49 1. 0613 0.34 0.34 1.0078 2.02 2.04 1.0143 3.69 3.74 1.0208 5.40 5.51 1.0014 0.37 0.37 1.0079 2.05 2.07 1.0144 3.72 4.77 1.0209 5.43 5.54 1. 0015 0.39 0.39 1.0080 2.07 2.09 1.0145 3.74 3.79 1.0210 5.45. 5.56 1.001(5 0.42 0.42 1.0081 2.10 2.12 1.0146 3.77 3.83 1.0211 5.48 5.60 1.0017 0.45 0.45 1.0082 2.12 2.14 1.0147 3.79 3.85 1.0212 5.50 5.62 1.0018 0.47 0.47 1.0083 2.15 2.17 1.0148 3.82 3.88 1.0213 5.53 5.65 1.0019 0.50 0.50 1.0084 2.17 2.19 1.0149 3.85 3.91 1.0214 5.55 5.67 1.0020 0.52 0.52 1.00&5 2.20 2.22 1.0150 3.87 3.93 1.0215 5.57 5.69 1.0021 0. 55 0.55 1.0086 2. 2:5 2.25 : 1.01 51 3.90 3.96 1.0216 5.60 5.72 1.0022 0.58 0.58 1.0087 2.25 2.27 1.0152 3.92 3.98 1.0217 5. 62 5.74 1.0023 0. 60 0.60 1.0088 2. 28 2.30 : 1.0153 3.95 4.01 1.0218 5. ,;.-> 5.77 1.0024 0.63 0.63 1.0089 2.30 2.32 I 1.0154 3.97 4.03 1.0219 5.67 5.79 1.0025 0.66 0.66 1.0090 2.33 2.35 1.0155 .00 4.06 1.0220 5.70 5.83 1.0026 0.68 0.68 1.0091 2.35 2.37 1.0156 .03 4.09 1.0221 5.72 5.85 1.0027 0.71 0.71 1.0092 2.38 2.40 1.0157 .05 4.11 1.0222 5.75 5.88 L.0028 0.73 0.73 1.0093 2.41 2.43 1.0158 .08 4.14 1.0223 5.77 5.90 1.0029 0.76 0.76 1.0094 2.43 2.45 1.0159 4.10 4.17 1.0224 5.80 5.93 1.0030 0.79 0.79 1.0095 2.46 2.48 1.0160 4.13 4.20 1.0225 5.82 5.95 1.0031 0.81 0.81 1. 0096 2.48 2.50 1. 0161 4.16 4.23 1.0226 5.84 5.97 1. 0032 0.84 0.84 1. 0097 2.51 2.53 1.0162 4.18 4.28 1.0227 5. S7 6.00 1.0033 0.87 0.87 1.0098 2.53 2.55 1.0163 4.21 4.28 1.0228 5. 89 6.02 1.0034 0.89 0.89 1.0099 2.56 2.59 1.0164 4.23 4.30 1.0229 5.92 6.06 1 . 0035 0.92 0.92 1.0100 2.58 2.61 1. 0165 4.26 4.33 1.0230 5.94 6.08 1.0036 0.94 0.94 1. 0101 2.61 2,64 1. 0166 4.28 4.35 1.0231 5.97 6.11 1.0037 0.97 0.97 1.0102 2.64 2. 67 1.0167 4.81 4.38 1.0232 5.99 6.13 1.003S .00 1.00 1. 0103 2.66 2.69 1.0168 4.34 4.41 1.0233 6.02 6.16 1.0039 .02 1. 02 1.0104 2.69 2.72 1. 0169 4.36 4.43 1.0234 6.04 6.18 1.0010 .05 1.06 1.0105 2.71 •_'. 71 1.0170 4.39 1. 1C, 1.0235 6.07 6. 21 1.0041 .08 1. OS 1.0106 2.74 2.77 1.0171 4.42 4.50 1.0236 6.09 (i. 23 1.0042 .11) 1.10 1.0107 2.76 2.79 1.0172 1. 11 4.52 1.0237 6.11 6.25 1.0043 .13 1.13 1.01 OS 2.79 2.82 1. 0173 4.47 4.55 1.0238 6.14 6.29 1.0044 .15 1.16 1. 0109 2. S2 2.85 1. 0174 4.50 4.58 1.0239 6.16 6.31 1.0045 .is 1.19 1.0110 2.84 2.87 1.0175 4.53 4.61 1.0240 6.19 6.34 1.0046 .21 1. 22 1.0111 2.87 2.96 1.0176 4.55 4.63 1.0241 6.21 6.36 L.0047 . 23 1. 24 1.0112 2. S9 2.H2 1.0177 4.58 4.66 1.0242 6. 24 6.39 1.0048 .26 .27 1.0113 2.92 2.95 1.017s 4.61 4.69 1.0243 6.26 6.41 1. 0049 . •_>'.» .30 1.0114 2.94 2.97 1.0179 4.88 1.71 1.0244 6.29 6.44 1.0050 .31 T32 1.0115 2.97 3.00 1.01 SO 1.66 1 4.74 ' 1.0215 6.31 6.46 1.0051 .84 .35 1.0116 2. 99 3.0?> 1.0181 4.69 1.77 1.02-16 6.34 6.50 1.0052 .86 .37 1.0117 3.02 3.06 L.0182 4.71 l.so 1.0247 6.36 6.52 1.0053 .39 .40 1.0118 3.0-5 3.09 1.0188 1. 71 L88 1.0248 6.39 6. 55 (.0054 .41 .42 1.0119 3.07 3.11 1.0184 4.77 4.86 1.0249 6.41 6.57 1.0055 .11 . If, 1.0120 3.10 3.14 1.0186 4.79 4.88 1.0250 6.44 6.60 L0056 . 1C. . 47 1.0121 3.12 ::. Hi 1.0186 4.82 4.91 1.0251 6.47 6.63 1. 0057 .49 . r>o L.0122 :•. L8 :;. 19 i. ins? 4.86 1.91 1.0252 6.50 6.66 LOOM .61 .52 1.0128 3.17 3.21 1.01SS 4.88 4.97 1.0253 6. 52 6.68 1.0059 .54 .55 1. 0124 3.20 3. 2 1 1. 0189 4.90 4.99 1.0254 6.55 6.72 1.0060 . r>c, .57 1.0125 3.23 3.27 1. 0190 4.93 5.02 1.0255 8.58 6. 75 1.0061 .59 . (iO 1.0126 :?. 2f> 3. 29 1.0191 4.96 5. 05 1.0256 6.61 6. 7S 1. 0062 .02 . <;:< 1.0127 :;. 2s X. XI L.0192 4.98 r>. os 1 . 0257 6.63 6.80 1.0068 .01 . 65 1.0128 3. :«) 8.84 L.0198 5. 01 5. 1 1 1 . 0'jf.S 15. 66 C,. S3 1.0064 .(17 .(is 1.012'.) 8.83 3.37 1.0194 5.04 ... 1 1 1. 0259 15. C>9 6. S6 •Calculated from results obtained by drying below 75° C. 128 PROVISIONAL METHODS FOB ANALYSIS OF FOODS. TABLE III. — Extract in beer wort — Continued. Extract. Extract. Extract. Extract. Specific gravity at!5°C. Per cent by weight. Grams per 100 cc. Specific gravity at!5°C. Per cent by weight. Grams 100 cc. Specific gravity it!5°C. Per cent by weight. Grams 100 cc. Specific gravitv at!5°C. Per cent by weight. Grams per 100 cc. 1.0260 6.71 6.88 1.0325 8.27 8.54 1.0390 9.92 10.31 1. 0455 11.53 12.05 1.0261 6.74 6.92 1.0326 8.29 8.56 1. 0391 9.95 10.34 1.0456 11.55 12.08 1.0262 6.77 6. 95 1. 0327 8.32 8.59 1.0392 9.97 10.36 1. 0457 11.57 12.10 1.0263 6.80 6.98 1. 0328 8.34 8.61 1.0393 9.99 10.38 1. 0458 11.60 12.13 1.0264 6.82 7.00 1. 0329 8.37 8.65 1.0394 10.02 10.41 1.0459 11.62 12.15 1.0265 6.85 7.03 1.0330 8.40 8.68 1.0395 10.04 10.44 1.0460 11.65 12.19 1.0266 6.88 7.06 1. 0331 8.43 8.71 1.0396 10. 06 10.46 1. 0461 11.67 12.21 1. 0267 6.91 7.09 1.6332 8.45 8.73 1.0397 10.09 10.49 1.0462 11.70 12.24 1.0268 6.93 7.12 1.0333 8.48 8.76 1.0398 10.11 10.51 1.0463 11.72 12.26 1.0269 6.96 7.15 1. 0334 8.51 8.79 1.0399 10.13 10.53 1.0464 11.75 12.30 1.0270 6.99 7.18' 1.0335 8.53 8.82 1.0400 10.16 10.57 1. 0465 11.77 12.32 1.0271 7.01 7.20 1.0336 8.56 8.85 1.0401 10.18 10.59 1.0466 11.79 12.34 1.0272 7.04 7.23 1.0337 8.59 8.88 1.0402 10.20 10.61 1.0467 11.82 12.37 1.0273 7.07 7.26 1.0338 8.61 8.90 1. 0403 10.23 10.64 1. 0468 11.84 12.39 1.0274 7.10 7.29 1.0339 8.64 8.93 1. 0404 10.25 10.66 1. 0469 11.87 12.43 1.0275 7.12 7.32 1. 0340 8.67 8.96 1.0405 10.27 10.69 1.0470 11.89 12.45 1.0276 7.15 7.35 1.0341 8.70 9.00 1.0406 10.30 10.72 1. 0471 11.92 12.48 1.0277 7.18 7.38 1. 0342 8.72 9.02 1.0407 10.32 10.74 1. 0472 11.94 12.50 1.0278 7.21 7.41 1. 0343 8.75 9.05 1.0408 10.35 10.77 1. 0473 11.97 12.54 1.0279 7.23 7.43 1.0344 8.78 9.08 1.0409 10.37 10.79 1. 0474 11.99 12.56 1.0280 7.26 7.46 1. 0345 8.80 9.10 1.0410 10.40 10.83 1. 0475 12.01 12.58 1.0281 7.28 7.48 1. 0346 8.83 9.14 1. 0411 10. 42 10.85 1.0476 12.04 12.61 1.0282 7.30 7.51 1. 0347 8.86 9.17 1.0412 10.45 10.88 1. 0477 12.06 12.64 1.0283 7.33 7.54 1.0348 8.88 9.19 1.0413 10.47 10.90 1. 0478 12.09 12.67 1. 0284 7.35 7.56 1. 0349 8.91 9.22 1.0414 10.50 10.93 1.0479 12.11 12. 69 1.0285 7.37 7.58 1.0350 8.94 9.25 1.0415 10.52 10.96 1. 0480 12.14 12.72 1.0286 7.39 7.60 1.0351 8.97 9.28 1.0416 10. 55 10.99 1. 0481 12. 16 12.74 1. 0287 7.42 7.63 1.0352 8.99 9.31 1.0417 10.57 11.01 1.0482 12.19 12.78 1.0288 7.44 7.65 1. 0353 9.02 9.34 1.0418 10.60 11.04 1.0483 12.21 12.80 1. 0289 7.46 7.68 1.0354 9.05 9.37 1. 0419 10. 62 11.06 1.0484 12.23 12. 82 1.0290 7.48 7.70 1.0355 9.07 9.39 1. 0420 10.65 11.10 1.0485 12.26 12. 85 1. 0291 7.51 7.73 1. 0356 9.10 9.42 1. 0421 10.67 11.12 1.0486 12.28 12.88 1.0292 7.53 7.75 1.0357 9.13 9.46 1.0422 10.70 11.15 1.0487 12.31 12.91 1.0293 7.55 7.77 1.0358 9.15 9.48 1. 0423 10.72 11.17 1.0488 12. 33 12.93 1. 0294 7.57 7.79 1.0359 9.18 9.51 1.0424 10.75 11.21 1.0489 12.36 12.96 1.0395 7.60 7.82 1.0360 9.21 9.54 1. 0425 10.77 11.23 1.0490 12.38 12.99 1.02% 7.62 7.85 1.0361 9.24 9.57 1.0426 10.80 11.26 1.0491 12. 41 13.02 1. 0297 7.64 7.87 1.0362 9.26 9.60 1. 0427 10.82 11.28 1.0492 12.43 13.04 1.0298 7.66 7.89 1.0363 9.29 9.63 1. 0428 10.85 11.31 1.0493 12.45 13.06 1. 0299 7.69 7.92 1.0364 9.31 9.65 1.0429 10.88 11.35 1.0494 12.48 13.10 1.0300 7.71 7.94 1.0365 9.34 9.68 1. 0430 10.90 11.37 1.0495 12.50 13.12 1.0301 7.73 7.96 1.0366 9.36 9.70 1. 0431 10.93 11.40 1.0496 12.53 13.15 1.0302 7.75 7.98 1. 0367 9.38 9.72 1. 0432 10.95 11.42 1.0497 12. 55 13.17 1.0303 7.77 8.01 1.0368 9.41 9.76 1.0433 10.98 11.46 1.0498 12.58 13.21 1.0304 7.80 8.04 1.0369 9.43 9.78 1.0434 11.00 11.48 1. 0499 12.60 13.23 1.0305 7.82 8.06 1.0370 9.45 9.80 1.0435 11.03 11.51 1.0500 12.63 13.26 1.0306 7.84 8.08 1.0371 9.48 9.83 1.0436 11.05 11.53 1. 0501 12.65 13.28 1.0307 7.86 8.10 1.0372 9.50 9.85 1.0437 11.08 11.56 1.0502 12.67 13.31 1.0308 7.89 8.13 1.0373 9.52 9.88 1.0438 11.10 11. 59 1. 0503 12.70 13.34 1.0309 7.91 8.15 1. 0374 9.55 9.91 1. 0439 11.13 11.62 1.0504 12. 72 13.36 1.0310 7.93 8.18 1.0375 9.57 9.93 1. 0440 11.15 11.64 1.0505 12. 75 13.39 1.0311 7.95 8.20 1. 0376 9.59 9.95 1.0441 11.18 11.67 1.0506 12.77 13. 42 1 . 0312 7.98 8.23 1.0377 9.62 9.98 1. 0442 11.20 11.70 1.0507 12.80 13.45 1.0313 8.00 8.25 1. 0378 9.64 10.00 1.0443 11.23 11.73 1. 0508 12.82 13.47 1. 0314 8.02 8.27 1. 0379 9.66 10.03 1.0444 11.25 | 11.75 1.0509 12.85 13.50 1.0315 8.04 8.29 1.0380 9.69 10.06 1. 0445 11.28 11.78 1.0510 12.87 13.53 1.0316 8.07 8.33 1.0381 9.71 10.08 1. 0446 11.30 1 11.80 1. 0511 12. 90 13. §6 1.0317 8.09 8.35 1.0382 9.73 10.10 1.0447 11.33 j 11.84 1. 0512 12.92 13.58 1.0318 8.11 8.37 1. 0383 9.76 10.13 1. 0448 11. 35 11.86 1.0513 12. 94 13.60 1. 0319 8.13 8.39 1. 0384 9.78 10.16 1.0449 11.38 11.89 1.0514 12.97 13.64 1.0320 8.16 8.42 1.0385 9.81 10.19 1.0450 11.40 11.91 1.0515 12.99 13.66 1.0321 8.18 8.44 1.0386 9.83 10. 21 1.0451 11.43 11.95 1.0516 ! 12.02 13.69 1.0322 8.20 8.46 1.0387 9.85 10. 23 1.0452 11. 45 11.97 1.0517 12. ni 13.71 L0628 8.22 8.49 1.0388 9.88 10.26 1.0453 11. 4S 12.00 1.0518 12.07 13. 75 1. 0324 8.25 8.52 1.0389 9.90 10.29 1.0454 11.. 50 12.02 1.0519H 12.09 13.77 REFERENCE TABLES. TABLE III. — Extract in beer ivort — Continued. 129 Specific gravity at!5°C. Extract. Specific gravity at!5°C. Extract. Specific gravity at!5°C. Extract. Specific gravity atlo°C. Extract. Per cent by weight. < i nuns per 100 cc. Per (Tilt by weight. (irjiins per 100 cc. Per cent by weight. (i ran is per 100 cc. Per cent by weight. Grams per 100 cc. 1.0520 13. 12 13.80 1.0585 14.75 15. til 1.0650 19.26 17.31 1.0715 17.81 19.08 1.0521 115.11 13.82 L.0686 14.78 16.65 1.0651 16.27 17.33 1.0716 17.84 19.12 1.0522 1:5. 1C, 13.85 1.0587 14.81 16.68 L.0652 16.30 17.36 1.0717 17.86 19.11 1.0523 18.19 13.88 1.0588 14.83 15. 70 L.0663 16.32 17.39 1.0718 17.88 19.16 1.0624 13. 21 13.90 1.0589 14.86 15.74 1.0654 16.35 17.42 1.0719 17.90 19.19 1.0525 13.24 13.94 1.0590 11. v.i 15.77 1.0655 16.37 17.44 1.0720 17.93 19.22 1.0526 13. 26 13.96 1.0591 14.91 15.79 1.0656 16.40 17.48 1.0721 17. 95 19. 24 1.0527 i:;.29 13.99 1.0592 11.94 15.82 1.0657 16. 42 17.50 1.0722 17.97 19. 27 1. 0528 13.31 14.01 1.0593 11. % 15.85 1.0658 16. 45 17.68 1.0723 17.99 19.29 1.0529 13.34 14. 05 1. 0594 14.99 15.88 1.0659 16.47 17.56 1.0724 18.02 19.32 1.0530 13.36 14.07 1.0595 15.02 15. 91 1.0660 16.50 17.59 1.0725 18.04 19.35 1.0531 13.38 14.09 1.05% 15.01 15.94 1.0661 16.52 17.61 1. 0726 18.06 19.37 1.0532 13.41 14. 12 1.0597 15.07 15.97 1.0662 16.54 17.68 1.0727 18.08 19.39 1.05:;:; 13.43 11. 15 1.0598 15. 09 15.99 1.0663 16.57 17.67 1.0728 18.11 19.43 I.o5:;i 13.46 14. 18 1.0599 15.11 16.02 1.0664 16.59 17.69 1.0729 18. 13 - 19.45 1. 0535 13. 48 14.20 1.0600 15. 14 16.05 1.0665 16. 62 17.7:; 1.0730 18.15 19.47 1.0536 13.51 14.23 1.0601 15. 16 16.07 1.0666 16.64 17. 75 1.0731 18.17 19.50 1.0537 13.53 14.26 1.0602 15.18 16.09 1.0667 16.67 17.78 1.0732 18.20 19. 53 1.0538 13.56 14.29 1.0603 15.20 16.12 1.0668 16.69 17.80 1.0733 18.22 19. 55 1. 0539 13.58 14.31 I.IM-.IU 15.23 16.15 1.0669 16.72 17.84 1.0734 IS. 2 1 19.58 1. 0540 13.61 14.34 L0606 15.25 16.17 1.0670 16.74 17.86 1.0735 18.26 19.60 l.u.Ml 18.68 14.37 1.0606 , 15.27 16.20 1.0671 16.76 17.88 1.0736 1 s. •_•>.. 19. 64 1.0542 13.66 14.40 1.0607 15.29 16.22 1.0672 16.79 17.'.''J 1.0737 18.31 19.66 1.0548 18.68 14.42 I.IH-.OS 15.31 16.24 1.0673 HI- HI 17.94 1.0738 18.33 19.68 1.05U 13.71 14.46 1.0609 16.34 L6.27 1.0674 16.84 17.98 1.0739 18.88 E9.71 1.0546 13.73 14.48 1.0610 15.36 16.30 1.0675 16.86 18.00 1.0740 18.88 19.74 1.0546 18.76 14.51 1.0611 15.38 16.32 1.0676 16.89 18.03 1.0741 is. 1(1 19.76 1.0547 18.78 14 53 1.0612 15.10 16.84 1.0677 16.91 18.05 1.0742 L8.42 19.79 1.0648 13.81 14. 57 1.0613 16. «:: 16.88 1.0678 if.. '.'i 18.09 1.0743 is. 11 19.81 1.0549 13.83 14.59 1.0614 15.45 16.40 1.0679 If,. '.'ti 18.11 1.0744 18.47 19.84 1.0550 13.86 14.62 1.0615 15.47 16.42 1.0680 II1.. 99 18. 15 1.0745 18.49 19.87 1. O.V.I 18.88 14.64 1.0616 i 15.49 16.44 1.0681 17.01 18.17 1.0746 18.51 19.89 1.0552 13.91 14.68 1.0617 ! 15.52 If.. is 1.0682 17.03 IS. 19 1.0747 is. 5:; 19.91 1.0553 13.93 14.70 l.Otils 15.54 16.50 l.Of.V, 17.06 18.23 1.0748 18.55 19.94 1.0554 13.96 14.73 1.0619 15.56 16. 52 1.0684 17.08 18.25 1.0749 18.57 19.96 1.0555 ia.ee 14.76 1.0620 15.58 16.56 1.0685 17.11 18.28 1.0750 18.59 19.98 1.0556 11.01 14.79 1.0621 15. 60 16.57 1.0686 17.13 18.31 1.0751 18.62 20.02 1.0557 14. OH 14.81 1 . IM',22 16.68 16.60 1.0687 17.16 18.34 ! 1.0752 18.64 20.04 1.0558 11. (Mi 14.84 1.0623 15.65 16.62 L.0688 17.18 18.36 1.0753 18.66 20.07 1.0559 11. OS 14.87 1. 0624 15.67 16.64 1.0688 17.21 18.40 1.0754 18.68 20.09 1.0560 14.11 14.90 1.0625 15.69 16.66 1.0690 17.23 18.42 1.0755 18.70 20.11 1.0561 11.11! 14.92 1.0626 15.72 16.70 1.0691 17. 25 18.44 1.0756 18.72 20.14 1.0562 14.16 14.96 1.0627 15.74 16.73 1.0692 17.28 1S.4S 1.0757 18.74 20.16 1.0563 1 1. is 14.98 1.0628 15.76 16.75 1.0693 17.30 IS. 50 1 1.0758 18.76 20.18 1.0564 11. 21 15.01 1.0629 15.78 1(1.77 1.0694 17.33 18.53 1.0759 18.78 20.21 1. 0565 14.23 15.03 1.0630 15.80 16.80 1.0695 17.35 18.60 1.07HO 18.81 •JO.'Jl 1.0566 14.26 15.07 1.0631 15.83 16.83 1.0696 17.38 18.59 1.07(11 18.83 20.26 1.0667 14.28 15.09 1.0632 ' 15.85 16.85 1.0697 17.40 is. til 1.0762 18.85 20. 29 1.0568 14.81 15. 12 1.0633 15.S7 16.87 1.0698 17.43 IS. (15 1.0763 18.87 20.31 1.0569 14.33 15.15 1.0634 15.S9 16.90 1.0699 17.45 18.67 1.0764 18.89 20. 33 1.0570 14..°,6 15.18 L.0685 15.92 16.93 1.0700 17.48 is. 70 1.0765 18.91 20. :;n L0671 14.88 15.20 1.0636 15. 94 16.95 1.0701 17.50 is. 7:; ! 1.0766 L8.9S 20.38 1.0672 14.41 15.23 1.0687 15.96 16.98 1.0702 17. 52 IS. 75 i 1.0767 18.95 20. 40 1.0673 11.11 15.27 1.0638 if,.' is 17.00 1.0703 17. W IS. 77 1.0768 18.97 20.43 1.H.-.71 11. ir, 15.29 1.0639 Ifl.ol 17.03 1.0704 17.57 IS. si ; 1.0769 19.00 20. If. L0676 1 1. I'.i 16.82 1.0640 16.03 17.06 1.0705 17.59 18.83 1.0770 19.09 20. 4S 1.0576 14.62 15.86 1.0641 16.05 17. OS 1.0706 17.61 L8.85 1.0771 19.04 20. 51 L0577 n.f.l 15.38 1.0642 16.07 17.10 1.0707 17.63 18,88 1.0772 19.06 20.53 1.0678 14.67 15.41 1.0643 16.09 17. 12 1.070N 17.66 18.91 1.077:; 19.08 20.55 1.0679 14.69 15.43 L.0644 16.12 17.16 1.0709 17.68 18.93 1.1*771 19.10 20.58 1.0580 14.62 15.47 L.0645 16.14 17.18 1.0710 17.70 18.96 1.0775 19.12 20.60 L.0681 14.66 15.50 L.0646 16.16 17.20 1.0711 17.7-2 18.98 1.0776 19.14 20.63 14.87 16.52 I.Of.17 1(1.18 17.28 1.0712 17.75 19.01 1.0777 19.17 20.66 1.0688 11.7H 15.68 1.0648 16.21 17.26 1.0718 17.77 19.04 1.0778 19.19 20.68 1.0684 11.7:: 15.59 1.0649 17.28 1.0714 17.79 19.06 1.0779 19.21 20.71 . <>5— 02- 130 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. TABLK III. — Extract in beer wort — Continued. Extract. Extract. Extract. Extract. Specific gravity at!5°C. Per cent by weight. Grams per 100 cc. Specific gravity at!5°C. Per cent by weight. Grams 100 cc. Specific gravity atl5°C. Per cent by weight. Grams per 100 cc. Specific gravity at 15° C. Per cent by weight. Grams per 100 cc. 1.07SO 19.23 20.73 1.0845 20. 70 22. 45 1.0910 22.19 24.21 1.0975 23.59 25. s-.i 1.0781 19. 25 20.75 1.0846 20. 73 22. 48 1.0911 22. 21 24. 24 1.0976 23. (51 25. '.12 .0782 19.27 20.78 1. 0847 20. 75 22. 50 1.0912 22. 23 24.26 1.0977 23. 63 25. '.) 1 .0783 19.29 20.80 1.0848 20. 77 22.53 1.0913 22. 26 24. 29 1.0978 23. 65 25. 97 .0784 19. 31 20.82 1. 0849 20. 79 22. 55 1.0914 ' 22.28 24.31 1.0979 23. 67 25. 99 .0785 19.33 20. 85 1. 0850 20.81 22. 58 1. 0915 22. 30 24.34 1.0980 23.69 26.01 . 078fi 19.36 20.88 1.0851 20.83 22. HI 1.0916 22. 32 24.37 1. 0981 23. 71 26.04 .0787 19.38 20. 90 1. 0852 20. 86 22.64 1.0917 22. 34 24.39 1. 0982 23. 73 26.06 .0788 19.40 20. 93 1. 0853 20. 88 22. 66 1.0918 22.37 24.42 1. 0983 23.76 26.09 .0789 19.42 20.95 1.0854 20.90 22.68 1. 0919 22. 39- 24.44 1.0984 23.78 26.11 .0790 19.44 20. 98 1. 0855 20. 93 22.72 1.0920 22.41 24.47 .0985 23.80 26.14 .0791 i 19.46 21. 00 1. 0856 20. 95 22. 75 1.0921 22.43 24.49 .0986 23.82 26.17 . 0792 19. 49 21.03 1. 0857 20. 98 22. 78 1.0922 22.45 24. 51 .0987 23. 84 26.19 .0793 19.51 21.06 1.0858 21.01 22. 81 1.0923 22.48 24. 54 .0988 23.86 26.22 .0794 19.53 21.08 1. 0859 21.04 22. S t 1.0924 22. 50 24. 56 .0989 23.38 26.24 .0795 19.56 21. 11 1. 0860 21. 06 22. S7 1.0925 22. 52 24. 60 .0990 23.90 26.27 .0796 19.58 21.14 1.0861 21.09 22. 90 1.0926 22. 54 24.62 .0991 23. 92 26.30 .0797 19.60 21. 16 1.0862 21.11 22. 93 1.0927 22. 56 24.64 .0992 23.94 26.32 .0798 i 19.63 21.20 1.0863 21.13 22. 96 1.0928 22. 59 24.67 .0993 23. 97 26.35 . 0799 19. 65 21.22 1.0864 21.16 22. 99 1. 0929 22. (11 24. 70 1.0994 23.99 26.37 .0800 19.67 21.24 1.0865 21.19 23. 02 1.0930 22.63 24.73 1.0995 24.01 26.40 .0801 19.70 21.28 i 1.0866 21.22 23.00 1.0931 22.65 24.76 1. 0996 24. 03 26.42 . 0802 19.72 21.30 1.0867 21.25 23.09 1.0932 22.67 24.78 1.0997 24.05 26.44 .0803 19.74 21.33 1.0868 21.2S 23.12 1.0933 22. 69 21. SI 1. 0998 24.07 26. 47 .0804 19.77 21.36 1. 0869 2 !.:;(» 23.15 1.0934 22.71 24. S3 1.0999 24. 09 26.49 .0805 19.79 21.38 1.0870 21.33 23.18 1.0935 22. 73 24.86 1.1000 24.11 26. 52 . 0806 19.81 21.41 1.0871 21.35 23. 21 1.0936 22. 75 24. 89 1.1001 24. 13 2(5. 55 .0807 19.84 21.43 1. 0872 21.37 23. 23 1.0937 •1-1. 77 24. 91 1.1002 24.15 21',. 57 . 0X08 19.86 21.46 1.0873 21.39 23. 2C. 1.0938 22. 80 24. 93 1.1003 24.17 26.60 .0809 19. 88 21., 19 1. 0874 21. 41 23. 2S 1.0939 22.82 24.96 1.1004 24.19 26.62 .0810 19.91 21.52 1.0875 21. 13 23. 31 1.0940 22.84 24. 99 1.1005 24.21 26.65 .0811 19.93 21.55 1.0S7C, 21.45 23. 33 1.0911 22. 86 25. 01 1. 1006 24. 23 26.68 . 0812 19.96 21.58 1.0877 21.47 23.36 1.0942 22.88 25.03 1.1007 24. 25 26.70 .0813 19.98 21. 60 1.0878 21.49 23.38 1. 0943 22.90 25. 06 1.1008 24.28 26.73 .0814 20.00 21.63 1.0879 21.51 23. 40 1.0944 22.92 25.08 1.1009 24.30 26. 75 . 0815 20.03 21.66 1.0880 21.54 23.43 1.0945 22. 94 25. 11 1.1010 24.32 26.78 . 0816 20.05 21.69 1.0881 21.56 23. 45 1.0946 '22. 96 25.14 1. 1011 24. 34 26.81 .0817 20.07 21.71 1. 0882 21.58 23.48 1.0947 22. 98 25. 16 1.1012 24.36 26. 83 . 0818 20.10 21.74 1.0883 21. (50 23.50 1.0948 23.00 25.18 1. 1013 24.39 26.86 . 0819 20.12 21.77 1.0884 21.62 23. 52 1.0949 23.03 25. 21 1.1014 24 .41 26.88 .0820 20.14 21. 79 1.0885 21.64 23.55 1.0950 23.05 25.24 1. 1015 24.43 26.91 . 0X21 20.17 21.83 1.0886 21.66 23.58 1.0951 23. 07 25. 26 1.1016 24.45 26. 93 . 0822 20.19 21.85 1.0887 21.68 23.60 1.0952 23.10 25. 29 1.1017 24.47 26. 95 .0823 20.21 21.87 1.0888 21.71 23. 63 1.0953 23. 12 25.31 1.1018 24. 49 26. 98 .0824 20.24 21.91 1.0889 21 . 73 23. 66 1.0954 23.14 25.34 1. 1019 24. 51 27.00 . 0825 20 26 21.93 1.0890 21.75 23. 69 1.0955 23.16 25.37 1.1020 24. 53 27.03 .0826 20.28 21.96 1.0891 21.77 23. 72 1.0956 23.18 25. 39 1.1021 24.55 27.06 .0827 20.31 21.99 1. 0892 21.79 23. 74 1. 0957 23. 20 25.42 1.1022 24.57 27.08 .0828 20.33 22.01 1.0893 21.82 23. 77 1.0958 23. 23 25.45 1.1023 24. 60 27.11 .0829 20.35 22.04 1. 0894 21.84 23.79 1.0959 23. 25 25. 47 1. 1024 24.62 27. 14 .0830 20. 37 22. 06 1.0895 21.86 23.82 1.0960 23. 27 25.50 1. 1025 24.64 27.17 .0831 20. 39 22. 08 1.0896 21.89 23. 85 1.0961 23.29 25. 53 1. 1026 24. 66 27.19 . 0832 20.41 22.11 1.0897 21. 91 23.87 1. 0962 23.31 25.55 1. 1027 24.68 27. 21 .0833 20.43 22.13 1. 0898 21.93 23.90 1. 0963 23.33 25.58 1.1028 24.70 27. 24 1. 0834 20. 46 22.16 1.0899 21.96 23.93 1.0964 23.35 25.60 1. 1029 24.72 27. 26 1.0835 •jo. is 22.19 1.0900 21.98 23.96 1. 0965 23.37 25.63 1.1030 24. 74 27. 29 1.0836 20.50 22. 21 1.0901 22. 00 23. 98 1.0966 23.39 25.66 1.1031 24. 76 27. 32 1.0837 20.52 22. 24 1.0902 22. 02 24. 01 1.0967 23.41 25.68 1. 1032 24.78 27.34 It 0838 20.54 22.26 1.0903 22.04 24.03 1.6968 23.44 25.71 1. 1033 24.81 27. *7 1.0839 20. 5r, 22.29 1.0904 22.06 24. 05 1.0969 23.46 25.73 1.1034 24.83 J7.39 i.i >s to 2<>.5«.i 22.32 1 . 0905 22,08 24.08 1.0970 23.48 25. 7. si 1. 1037 24.89 27. 17 1.0843 21 Mil1, 22. 40 1.0908 22. I.') 24.16 1.0973 23. 55 25.84 1.1038 24.92 27.50 l.i- II 20.68 22. VI 1.0909 22. 17 21. is 1.0974 23.57 25.86 1.1039 24.94 27.53 REFERENCE TABLES. TABLE III. — Kctract in beer wort — Continued. 131 Specific gravity atl.V(;. Extract. Specific gravity at 15° C. Extract. Specific gravity at!5°C. Extract. Specific- gravity at!5°C. Extract. ivr cent by weight. Grams per 100 cc. Per cent by weight. (irams per 100 cc. Per cent by weight, Grams per 100 cc. Per cent by weight. Grama per 100 cc. .1040 24.% 27.56 1. 1095 26. 16 29.03 L1150 27.29 30.43 1. 1205 28.38 31.81 .1041 24. 98 27.58 1.1096 26. is 29.06 .1151 27.31 30.45 1. 1206 28.40 31.83 .11)12 25. 00 27.60 1.1097 •jr.. 20 29. 08 . 1152 27. 33 30.47 1.1207 28.42 31.86 .1048 25.03 27.63 1.1098 26.28 29. 1 1 . 1153 27. 35 30.50 1.1208 28.44 31.88 . 1011 25.05 27.66 1.1099 •JC.. 25 29. 13 .1154 27.37 30.52 1.1209 28.46 31.90 .1045 25.07 27.69 1.1100 26.27 29. 16 .1155 27.38 30.55 1. 1210 28.48 31.93 .1046 25.09 27. 72 1.1101 26.29 29. 19 . 1156 27. 40 30.57 1.1211 28.50 31. 95 .1047 25.11 27.74 1.1102 26.31 29.21 1.1157 27. 42 30. 59 1.1212 28.52 31.98 .1048 25.14 27.77 1.1103 26.:!:; 29.24 .1158 27.11 30.62 1.1213 28.54 32.00 .1049 25.16 27.79 1.1104 28,35 2-.». 26 . 1159 27.46 30.64 1.1214 28.56 32.03 .1060 25.18 27.82 1.1105 26.:;7 29.29 .1160 27. 4S 30.67 1. 1215 28.58 32. 05 .1051 25. 20 27. 85 1.1106 26.:;'.» 2'.«. :',2 .1161 •27. 50 30. 69 1. 1216 28.60 32.08 . 1052 25.22 27.87 1.1107 26.41 29.34 . 1162 27.52 30.72 1.1217 28.62 32.11 .1053 25.24 27.90 1.1 Ids -jc,. u 29.37 .1168 27.54 30.75 1.1218 28.64 32.13 .1054 25.27 27.93 1.1109 26. it; 29.39 . 1164 27. 56 30.77 1.1219 28.66 32.15 1.1055 25.29 27.% 1.1110 26.48 2'.». 12 . 1165 27. 58 30. 80 1.1220 28.68 32.18 1.1056 25. 31 27.98 1.1111 -1C,.:*} 29.44 .1166 27.60 30.82 1.1221 28.70 32.20 1.1057 25.33 28.00 1.1112 26.52 •».<. Hi .1167 27.62 30.85 1.1222 28.72 32.23 1. 1058 25.35 28.03 1.1113 26.54 29.49 .1168 27.61 30.87 1.1223 28.74 32.25 1. 1059 25.38 28.06 1.1111 26.56 29.51 .1169 27.66 30.89 1.1224 28.76 32.27 1.106C 25.40 28.09 1.1115 26.58 •_".i. :> 1 .1170 27.68 30.92 1.1225 28.78 32.30 1.1061 25.42 28.12 1.1116 26.60 29.57 .1171 27.70 30.94 1.1226 28.80 32.32 1.1062 25. 44 28.14 1.1117 26.62 •_•'.». :.'.» .1172 27.72 30.97 1.1227 •js!sj 82.85 1.1063 25.46 28.17 1.1118 26. 64 29.61 .1173 27.71 31.00 L.1228 28.84 32.37 1.1064 25.48 28.19 1.1119 26.66 29.64 .1171 27.76 31.02 1.1229 28.86 32.40 1.1065 25.50 28. 22 1.1120 26. 6s 29.67 .1175 27. 78 31.05 1.1230 28.88 82. «:: 1.1066 25. ;YJ 28.25 1. 1121 26. 70 29.69 .1176 27.80 :U.o7 1.1231 28.90 82. »:. 1.1067 25. 54 2X. -11 1.1122 26. 72 29.71 .1177 •11. v_' 31 . 09 1. 1232 28.92 82.48 ;. KMis. 25.57 28.30 1.1128 26. 75 •J'.i. 7 1 .117* •11. si :;i. 12 1.1233 28.94 32.50 1.1069 25.59 28.32 1.1124 26. 77 29.77 .1179 27. Ni 31.15 1.1234 26.96 32. .53 1. 1070 25.61 28.35 1.1125 26.79 29.80 .1180 2.7.88 31.18 1.1235 28.98 82.56 1. 1071 25 63 28.38 L.1126 26.81 29.83 .1181 27.90 31.20 1.1236 29.00 32. 58 1. 1072 25.65 28.40 1.1127 26.88 29.85 .1182 27.92 31.23 1. 1237 29.02 82.60 1.1073 25. 117 28.43 1.1128 •Jti. s:> 29.88 .1183 27.94 81.26 1.1238 29.04 32.63 1.1074 25.69 28.45 1.1129 26. S7 29.90 .1184 27.% 31.27 1. 1239 29.06 32.65 1. 1075 25.71 28.48 1.1130 26.89 29.93 .1185 27.98 :;i.:;o 1.1210 29.08 32.68 1. 1076 25.73 28. a 1.1131 26. '.U 29.95 .1186 28.00 31.32 1.1241 29.10 32.71 1.1077 25.75 28.53 1. 1132 26.93 29. '-'7 .1187 28.02 31.35 1.1242 29. 12 32.73 1. 1078 25.78 28.56 1.1133 26. !»f> 30.00 .1188 28.04 31.37 1.1243 29. 14 32.76 1.1079 25.80 •js. r,s i.n:;i 26. '.(7 30.02 .1189 28.07 31.10 l.TJll 29.16 32.78 1.1080 25.82 28.61 1. 1135 26.99 30.06 .1190 28.09 31.43 1.1245 29.18 32.81 1. 1081 25.84 28.64 1.1136 27.01 30.08 .1191 2s. 1 1 31.45 1.TJ16 29.20 32.83 1.1082 25.86 28.66 L.1187 27. 03 30.10 .1192 28.18 :;i. is l.U 17 29.22 32.86 1.1083 25.89 28.69 1.1188 27.06 30.13 .1193 28. i:. 81.51 ! 1.1248 29.24 32.89 1 1084 25.91 28.72 1. 1139 27.07 30.15 .1194 28.17 31.53 1.1249 29.26 32.91 1.1085 25.93 28.75 1. 1140 27. W 30.18 1.1195 28.19 31.56 1.1250 29.28 32.94 1.1086 25.96 28.78 1.1141 27.11 30. 20 1.1196 28.21 ::].:.'.» 1.1251 29.30 32.% 1.1087 25. <»S 28.80 1. 1142 27.13 30.22 1.1197 28.23 :;i.6i 1.1262 29.32 32.99 1. 108T, 26. 01 28.83 1.1143 27. i:> 30.25 1. 11 '.is 28.25 31.63 l.u:.:; 29.34 33.02 1. 1089 26.03 28.86 Mill •11. 17 30.27 1.1199 28.27 31.65 ! 1.1254 29.36 33.04 1.1090 26.05 28.89 1.1145 27. 19 30.31 1.1200 81.68 .1255 29.38 33.07 1.1091 26.07 28.92 1.1 in; 27.2] 30.33 1.1201 28.30 31.7«i .1266 29.40 33.09 L.1092 26.09 28.94 1 1 1 17 27. J:i 80.36 1.1202 •js. 32 31.73 .1257 29.42 33.12 1.1098 26.12 28. '.IT 1. Ills 27. '-'.'> 80.87 1. 12":; •Js. :• l 31.76 .1288 29.46 33. I ' 1 in-., i •J6 1 1 29.00 1.11 111 27.27 30.40 1.1284 28.36 BL78 . 1269 •J'.». !7 83.17 132 PEG VISIONAL METHODS FOR ANALYSIS OF FOODS. TABLE IV. — Extract in beer wort. a [According to H. Ellion.] Specific gravity ft«°c. Extract. Specific gravity at«C« Extract. Specific gravity atH°C. Extract. Specific gravity atH°C. Extract. Per cent by weight. Grams per 100 cc. Per cent by weight. Grams per 100 cc. Per cent by weight. Grams per 100 cc. Per cent by weight. Grams per 100 cc. 1.0001 0.02 0.02 1.0066 1.63 1.64 1.0131 3.22 3.26 1. 0196 4.79 4.89 1.0002 0.05 0.05 1.0067 1.66 1.67 1.0132 3.25 3.29 1.0197 4.82 4.91 .0003 0.07 0.07 1.0068 1.68 1.69 1.0133 3.27 3.31 1. 0198 4.84 4.94 .0004 0.10 0.10 1. 0069 1.71 1.72 1.0134 3.29 3.34 1. 0199 4.87 4.96 .0005 0.12 0.12 1.0070 1.73 1.74 1.0135 3.32 3.36 1.0200 4.89 4.99 .0006 0.15 0. 15 1.0071 1.76 1.77 1. 0136 3.34 3.39 1.0201 4.91 5.01 .0007 0.17 0.17 1.0072 1.78 1.79 1.0137 3.37 3.41 1.0202 4.94 5.04 .0008 0.20 0.20 1.0073 1.80 1.82 1.0138 3.39 3.44 1.0203 4.96 5.06 .0009 0.22 0.22 1.0074 1.83 1.84 1. 0139 3.42 3.46 1.0204 4.99 5.09 .0010 0.25 0.25 1.0075 1.85 1.87 1.0140 3.44 3.49 1.0205 5.01 5.11 .0011 0.27 0.27 1.0076 1.88 1.89 1.0141 3.46 3.51 1.0206 5.03 5.14 .0012 0.30 0.30 1.0077 1.90 1.92 1.0142 3.49 3.54 1.0207 5.06 5.16 .0013 0.32 0.32 1.0078 1.93 1.94 1.0143 3.51 3.56 1.0208 5.08 5.19 1.0014 0.35 0.35 1.0079 1.95 1.97 1.0144 3.54 3.59 1.0209 5.11 5.21 1.0015 0.37 0.37 1.0080 1.98 1.99 1.0145 3.56 3.61 1.0210 5.13 5.24 1.0016 0.40 0.40 1.0081 2.00 2.02 1.0146 3.59 3.64 1.0211 5.15 5.26 1.0017 0.42 0.42 1.0082 2.03 2.04 1.0147 3.61 3.66 1.0212 5.18 5.29 1.0018 0.45 0.45 1.0083 2.05 2.07 1.0148 3.63 3. 69 1.0213 5.20 5. 31 1. 0019 0.47 0.47 1.0084 2.07 2.09 1.0149 3.66 3.71 1.0214 5.23 5. 31 1.0020 0.50 0.50 1.0085 2.10 2.12 1.0150 3. 68 3. 74 1. 0215 5.25 5.36 1.0021 0.52 0.52 1.0086 2.12 2.14 1.0151 3. 71 3. 76 1.0216 5.27 5.39 1.0022 0. 55 0. 55 1.0087 2.15 2.17 1.0152 3.73 3.79 1.0217 5.30 5.41 1.0023 0.57 0.57 1.0088 2.17 2.19 1.0153 3.76 3. XI 1.0218 5.32 5.44 1.0024 0.60 0.60 1.0089 2.20 2.22 1.0154 3.78 3.84 1.0219 5. 35 &.46 1.0025 0.62 0.62 1.0090 2.22 2.24 1.0155 3.80 3.86 1.0220 5.37 5. 19 1.0026 0.65 0. (15 1.0091 2.25 2.27 1.0156 3.83 3.89 1.0221 ">.39 5. 51 1.0027 0.67 0.67 1.0092 2.27 2.29 1.0157 3.85 3.91 1.0222 5.42 5. 54 1.0028 0.69 0.70 1.0093 2.29 2.32 1.0158 3.88 3.94 1.0223 5.44 5.56 1.0029 0.72 0.72 1.0094 2.32 2.34 1.0159 3.90 3.96 1.0224 5.47 5.59 1.0030 0.74 0.75 1.0095 2.34 2.37 1.0160 3.93 3.99 1.0225 5.49 5.61 1.0031 0.77 0.77 1.0096 2.37 2.39 1. 0161 3.95 4.01 1.0226 5.51 5. 154 1.0032 0.79 0.80 1.0097 2.39 2.42 1.0162 3.97 4.04 1 . 0227 5. 54 5.66 1.0033 0.82 0.82 1.0098 2.42 2.44 1. 0163 4.00 4.06 1.0228 :>.:>. 14 1.0064 1.58 1.59 .0129 3.17 3.21 1. 0194 4.75 4.84 1.0259 6.30 6.46 1.0065 1.61 1.62 .0130 :;.•->(> 3.24 1. 0195 4.77 4.86 1. 0260 6.32 (i.49 1 1 Calculated from results obtained by drying at 97° C. REFERENCE TABLES. TABLE IV. — Extract in beer wort — Continued. 133 Specific gravity atH°C. Extract. Specific S$g Extract. Specific gravity at«°C. Extract. Specific $&%. Extract. Per cent by weight. ( irsiins per 100 cc. Per cent by weight. Grams per 100 cc. Per cent by weight. Grams per 100 cc. Per cent by weight. Grams per 100 cc. L.0261 6.35 6.51 1.0326 7.89 8.14 1.0391 9.41 9.77 1.045(5 10.91 11.41 1 . ui>r,-j 6.37 6.64 1.0327 7.91 8.17 1.0392 9.43 9.80 1. 0457 10.93 11.43 1.0263 6.40 6.56 1. 0328 7.93 8.19 1.0393 9.45 9.82 1.0458 10.96 11.40 1.0264 6.42 6.59 .0329 7.96 8.22 1.0394 9.48 9.85 1.0459 10.98 11.48 1.0265 6.44 6.61 .0330 7.98 8.24 1.0395 9.50 9.87 1.0460 11.00 11.51 .0266 6.47 6.64 .0331 8.00 8.27 1.0396 9.52 9.90 1.0461 11.03 11.53 . U2C.7 6.49 6.66 . 0332 8.03 S. li'.l 1.0397 9.55 9.92 1.0462 11.05 11.56 .0268 6.51 6.69 .0333 8.05 8. 32 1. 0398 9.57 9.95 1.0463 11.07 11.58 .0269 6.54 6.71 .0334 8.07 8.34 1.0399 9.59 9.97 1.1464 11.09 11.61 .0270 6.56 6.74 . 0335 8.10 8.37 1.0400 9.62 10.00 1.0465 11.12 11.63 ,0271 6.59 6.76 .0336 8.12 8.39 1.0401 9.64 10.03 1.0466 11.14 11.66 . 0272 6.61 6.79 .0337 8.14 s. 12 1.0402 9.66 10. 05 1.0467 11.16 11.68 .0273 6.63 6.81 .0888 8.17 s. 11 1.0403 9.69 10.08 1.0468 11.19 11.71 .0274 6.66 6.84 .0339 8.19 8.47 1.0404 9.71 10.10 1.0469 11.21 11.74 .0275 6.68 6.86 .0340 8.2] 8. I1.' 1.0405 9.73 10.13 1.0470 11.23 11.76 .0276 6.70 6.89 .0341 8.24 8.52 1.0406 9.75 10. 15 1.0471 11.26 11.79 .0277 6.73 6.91 .0342 8.56 8.54 1.0407 9.78 10.18 L.0472 1 1 . L's 11.81 .0278 6.75 6.94 .0343 8. f,7 1.0408 : 8.87 1.0420 10.08 10.60 1.0485 11.58 12.14 .0291 7.06 7.27 1.0356 8.59 8.90 1.0421 10.10 10.63 1.0486 11.60 12.16 .0292 7.08 7.29 l.(i:;:,7 8.61 8.92 1.0422 10.13 10.66 L.0487 1 1 . C.'J 12. 19 .0293 7.11 7.32 1. 0358 8.64 8.95 L.0428 10. i:. 10.68 1.0488 1 1 . r>:> 12.21 .0294 7.13 7.34 1.0359 8.66 8.97 L.0424 KM: KI..;,, L0489 Il.tiT 12.24 .0295 7.i:. 7.37 1.0360 8.68 9.00 1. 0426 10.20 10.68 1.0490 11.69 12.26 .0296 7.18 7.39 1.0361 8.71 9.02 i.in-jf, ni.-j-j 10.65 i.oi-.n 11.71 12.29 .0297 7.20 7.42 1.0362 8.73 9.05 L.0427 10.24 10.68 L0492 11.71 12. 31 .0298 7.23 7. II 1.0363 8.75 9.07 1.0428 10.26 10.70 1.0498 11.76 12.34 .0299 7.25 7. 17 1.0364 8.78 9.10 L.0429 10.29 10. 73 1.0494 1 1 . TS 12.36 .0300 7.27 7.49 1.0365 8.80 9.12 1.0430 10.31 10. 75 1.0495 11.81 12. 39 .0301 7.30 7.52 1.0366 8.82 9.15 l.or.l 10.33 10.78 1.0496 IL88 12.42 .0302 7.32 7.54 1.0367 s. s:, 9.17 1.0482 10.36 10.80 1.0497 1 1 . s:, PJ. II .0303 7.34 7.57 1.0368 8.87 9.20 1.0433 10.38 10.83 1.0498 LL87 12.47 .0304 7.37 7.59 1.0369 s. s-.» 9.22 1.0434 10.40 L0.86 1.0499 11.90 12.49 .0305 7.39 7. (\'2 1.0370 8.92 9.25 1.0435 10.43 10. MS 1.0500 11.92 12.52 .0306 7.41 7.64 1.0371 s. '.i 1 9.27 1.0436 10. 45 10.90 1.0501 11.94 12.54 .0807 7. II 7.67 1.0372 s. % 9.30 1.0437 10.47 10.93 1.0502 1 1 . '.17 12.67 .0808 7.46 7.69 1.0:57:5 8.99 9.32 1.0438 10.50 10.96 1.0503 11.99 L2.69 .0909 7. 49 7.72 1.0374 9.01 9.85 1.0439 10.52 10.98 1.0504 12. 01 12.62 .0310 7.51 7.74 1. 0375 9.03 9.37 1. 0440 10.54 11.01 1.0505 12.03 12.64 .08U 7.53 7.77 L0876 9.06 9.40 1.0441 10.56 11.08 1.0506 12.06 12.67 .0812 7.56 7.79 1.0377 9.08 9.42 L.0442 10.59 11.06 1.0507 12.06 12. 69 .0818 7.58 7.82 1.0378 '.». ll) 9.45 1.0443 10.61 11. OS 1.0508 12.10 12. 72 .0814 7.60 7. si L0879 9.13 9.47 1.0444 10.63 11.11 1.0509 12.13 12.74 .0315 7.63 7.87 1.0880 9.15 9.50 L.0446 10.66 11.13 1.0510 i-j. i:> 12.77 .0816 7.65 7. .v.i 1.0881 9.17 9.52 1.0446 10.68 11.16 1.0511 12.17 12.79 .0817 7.67 7.92 L0882 9.20 9.55 1.0447 10.70 11.18 1.0612 12.19 12.82 .0318 7.70 7.94 1.0888 '.». L"_' '.». 57 L.0448 10.7:; 11. LM L.0618 12.22 12.84 .0319 7.72 7. <>7 1.0384 9.24 9.60 1.0449 10.7:. 11.28 I.O.M 1 L2.24 12.87 .0320 7.74 7.99 1.0886 '.». 27 '.». »!•_' 1.0460 10.77 11.26 1.0616 12.26 12.89 .0821 7.77 8.02 1.0386 9.29 '.». li". L045] 10.80 1 1 . -j.s L0516 12.28 12.92 .0822 7. 7'.i 8.04 1.0387 9.31 16.66 0729 17.06 18.30 1.0535 12.72 13. 40 1.0600 14.19 15.04 1.0665 15.64 16,68 0730 17.08 18.33 1.0536 12.74 13.42 1.0601 14.21 15. 06 1.0666 15. (iti 16.71 0731 17.10 18.55 1.0537 12.76 13.45 1.0602 14.23 15. 09 1.0667 15.69 16.73 0732 17.12 18.38 1.0538 12.79 13.47 1.0603 14.25 15. 11 1.0668 If). 71 16.76 0733 17.15 18.40 1.0539 I 12.81 13.50 1.0604 14.28 15.14 1.0669 15. 73 16.78 0734 17.17 18.43 1. 0-540 12.83 13.52 1.0605 14.30 15.16 1.0670 15. 75 16.81 0735 17.19 18.45 1. 0541 12.85 13.55 1. 0606 14.32 15.19 1. 0671 15. 77 16.83 0736 17.21 18.48 1.0542 12.88 13. 57 1.0607 14.34 15.21 1. 0672 15.80 16. 86 0737 17.23 18.50 1.0543 12.90 13. 60 1.0(508 14.37 15.24 1.0673 15. 82 16.88 0738 17.26 18. 53 1. 0544 12. 92 13. 62 1. 0609 11. :'.'.» 15.27 1.0674 15.84 16. 91 0739 17.28 18.55 1. 0545 12.94 13.65 1. 0610 14.41 15. 29 1.0675 15.86 16. 93 0740 17.30 18.58 1.05 Hi 12.97 13. 68 1.0611 14.43 15. 32 1. 0676 15.89 16.96 0741 17. 32 18.61 1. 0,547 12. 99 13. 70 1.0612 14.46 15. 34 1 . 0(577 15. 91 16.98 0742 17.34 18.63 1. 0548 13. 01 13.73 1.0613 14.48 15.37 1.0678 15.93 17.01 0743 17.37 18.66 1.0549 13.04 13.75 1.0614 14.50 15. 39 1.0679 15.95 17.03 0744 17.39 18.68 1.0550 13.06 13.78 1.0615 14. 52 15.42 1.0680 15.97 17.06 0745 17.41 18.71 1.0551 13.08 13.80 1.0616 14,55 15. 44 1.0681 16.00 17.09 0746 17.43 18.73 1. 0552 13.10 13.83 1.0617 14.57 15.47 1. 0682 16.02 17.11 .0747 17.45 18.76 1. 0553 13.13 13.85 1.0618 14.59 15.49 1.0683 16. 04 17.14 0748 17.48 18.78 1. 0554 13.15 13.88 1.0619 14.61 15. 52 1.0684 16.06 17.16 0749 17.50 18.81 1. 0555 13.17 13.90 1. 0620 14.64 15. .54 L0685 16.09 17,19 .0750 17.52 18.83 1.0.556 13.19 13.93 1.0621 14.66 15. 57 1 0686 16. 11 17.21 .0751 17.54 18.86 1. 0557 13. 22 13.95 1. 0622 14.68 15. 59 1.0687 16.13 17.24 . 0752 17.56 18.88 1. 0558 13.24 13.98 1.0623 14.70 15. 62 1.0688 16. 15 17.26 .0753 17.59 18.91 1. 0559 13.26 14.00 1 . 0624 14.73 15.64 1.0689 16.17 17. 29 .0754 17.61 18.93 1.0560 13.28 14.03 1.0625 14.75 15.67 1.0690 16.20 17.31 .0755 17.63 18. 96 1.0561 13.31 14.05 1.0626 14.77 15. 69 1.0691 16.22 17.34 .0756 17.65 18.99 1.0562 13.33 14.08 1.0627 14.79 15. 72 1. 0692 16.24 17.36 .0757 17.67 19.01 1.0563 13.35 14.10 1.062H 14.81 15. 75 1. 0693 16. 26 17.39 . 0758 17.69 19.04 1. 0564 13.37 14.13 1.0629 14.84 15. 77 1.0694 16. 28 17.41 . 0759 17. 72 19.06 1.0565 13.40 14. 15 1.0630 14.86 15.80 1.0695 16.31 17.44 .0760 17.74 19.09 1.0666 13.42 14.18 1.0631 14.88 15,82 1.0696 16.33 17.47 . 0761 17.76 19.11 1.0567 13.44 14.20 1.0632 14.90 16.85 1. 0697 16. 35 17.49 . 0762 17. 78 19.14 1.0668 13. 47 14.23 1.0633 14.93 15..S7 1.0698 16.37 17. 52 .0763 17.80 19.16 1.0569 13.49 14.26 1.0634 14.96 15.90 1.0699 16. 40 17.54 .0764 17.83 19.19 1. 0570 13.51 14.28 1.0635 14.97 15.92 1.0700 16 42 17.57 .0765 17.85 .19. 21 1 . 0571 13.53 14.31 1.0686 14.99 15.95 1.0701 16.44 17.59 .0766 17.87 19.24 1.0572 13.56 14.33 1.0637 Ifi.to 15.97 1.0702 16.46 17.li'J .0767 17.89 19.26 1.0573 13.58 14.36 1.0638 15.04 16.00 1.0703 16.48 17. 64 .0768 17.91 19. 29 1.0674 13.60 14.38 1.0639 15. 06 16.02 1.0704 16.51 17. 67 .0769 17.94 19.32 1.0575 13.62 14.41 1.0640 15.08 16. 05 1.0705 1C,.. 53 17.69 .0770 17.96 19.34 1.0576 13.65 14.43 1.0641 15. 11 16.07 1.0706 16.55 17.72 .0771 17.98 19.37 1.0577 13.67 14.46 1.0642 15. 13 16.10 1.0707 16.57 17.74 . 0772 18.00 19.39 1 . 057X 13.69 14.48 1.0643 16.16 16.12 1.0708 16.59 17.77 . 077:5 18.02 19.42 1.0579 13.71 1 1.51 1.0644 lf>. 17 16.15 1.0709 16.62 17. 79 . 0774 18.05 19.44 1.05X0 13.74 14.58 1.0645 i:>. lit 16.18 1.0710 1«. 64 17.82 .0775 18.07 19.47 1 . 0581 13.76 14.56 1.0(1 1C, 15.22 16.20 1.0711 16.66 17.85 . 0776 18.09 19.49 1.0582 13.78 14.68 1.0647 16.24 16.28 1.0712 16.68 17.87 .0777 18.11 19.52 1.1 >.->*:>, 13.80 14.61 1.064X 15.26 16.25 1.071:; 16.70 17 9(1 .0778 18.13 19.54 1 . 05s | 13.83 14.68 1.0649 15.28 16. 28 1.0714 16.73 17. 92 . 0779 18 15 19.57 L.0685 13.85 14.66 1.0650 15.31 16 30 1.0715 16.75 17 95 . 07SO 18.18 19, 59 1 1 REFERENCE TABLES. TABLE IV. — E.dr,•/ — Continued. 135 Specific gravitv a. ;:;<•. Extract. Specific gravity at}g°C. Extract. Specific gravity aHf°C. Extract. Specific gravity at |f° C. Extract. Per cent by weight, Grama per 100 cc. Per cent by weight. Grams per 100 cc. Per cent by weight. Grams per 100 cc. Per cent by weight. Grams per 100 cc. .0781 18. 20 19.62 1.0836 19.39 21. 02 1.0891 20.58 22.41 1.0946 21.76 23. 81 . 07S-J 18.22 19.64 1.0837 19. 42 21.04 1.0892 20.60 22.44 1.0947 21.78 23.84 .0783 18.24 19. 67 1.0838 19.44 21.07 1.0893 20. 62 22.47 1.0948 21.80 23.87 .0784 18.26 19.70 1.0839 19.46 21.09 1.0894 20. tir> 22. 49 1.0949 21. 82 23.89 .0785 18.29 19. 72 1.0840 19. IS 21. 12 1.0895 20. (17 22.52 1.0950 21-84 23.92 .0786 18.31 19.75 1.0841 19.50 21.14 1.0896 20.69 22.54 1.0951 21.86 23.94 .0787 18.33 L9.77 1.0842 19.52 21. 17 1.0S97 20. 71 22. 57 1.0952 21.88 23.97 .0788 18.35 19.80 1.0843 19! 55 21. 19 1.0898 20.73 22.59 1.0953 21.91 23.99 .0789 18.37 19. 82 1. 0844 19. 57 21.22 1.0899 20. 75 22.112 1.0954 21.93 24.02 .0790 18.39 19.85 1. 0845 19.59 21.24 1.0900 20. 77 22. .11 1.0955 21.95 24.04 .0791 18.42 19.87 1.0846 19.61 21.27 1.0901 20. 79 22.67 1.0956 21.97 24.07 . 0792 18.44 19.90 1.0847 19.63 21.30 1.0902 20. S2 22. (19 1.0957 21.99 24.09 .0793 18.46 19.92 1.0848 19.66 21. 32 1.0903 20.84 22. 72 1.0958 22.01 24.12 .0794 18.48 19.96 1.0819 19.68 21.35 1.0904 20.96 22. 7.', 1.0959 22. 03 24. 15 .0795 18.50 19.97 1.0850 69. 70 21.37 1. 0905 20.88 ±2. 77 1.0960 22.05 21.17 .079(5 18.53 20.00 1.0851 19.72 21.40 1.0906 20.90 22.80 1.0961 22.08 24.20 .0797 18. 55 20.03 1.0852 19.71 21. 12 1.0907 20.92 22. xj 1.0962 22.10 24.22 . 079S 18.57 20. 05 1.0853 19. 76 2L46 1.0908 20.91 L.096S 22.12 21.2.', .0799 18.89 20.08 1.0864 19.78 21.47 1.0909 20.97 22. ^7 1.0964 22.14 24. 27 .0800 18.61 20. 10 1.0855 19.81 21.50 1.0910 20.99 22.90 1.0965 22.1(1 24. 30 .0601 18.63 20.13 1.0856 19.83 21.52 1.0911 21.01 22.92 i.on.it; 22.18 24.32 . 0802 18.66 20.15 1.0867 19.86 21.66 1.0912 21.03 22. I'.'. 1.09(17 22. 20 24.85 .0808 18.68 20.18 1.0868 19.87 21.58 L0918 21.05 22. 97 1. 11; ir,s 22.22 24. 38 .0804 18.70 20. 20 L.0869 19.89 21.60 1.0914 21. (i7 23.00 L.0969 22.2:, 24.40 .0805 18. 72 20.23 1.0860 19. 91 21.63 1.0915 21.09 23.02 1.0970 22.27 24.43 . OSOli 18.74 20.25 l.ONii 1 9.9:', 21.65 1.0916 21.12 23.05 1.0971 22.29 21. 15 .0807 18.77 20. 28 1.0862 L9.98 21.68 1.0917 21.11 23.08 .0972 22.31 21. IS .0808 18. 79 20.30 L.0863 ID. US 21.70 LOWS 21.1(1 23.10 .0973 22.:::'- 24. 50 .0809 18.81 20.33 1.0864 20.00 21.73 1.0919 21. is 23.13 . 0974 22. #i 21.;,:; .0810 18.83 20.36 1.0865 20.02 21.7.-, 1.0920 21.20 23. 15 .097.-, 22.:',7 24.56 . 0811 18.85 20.38 1.0866 20.04 21.78 1.0921 21.22 23.18 .0976 22. 39 24.58 .0812 18.87 20. 41 Lost 17 20. Oti 21.80 1.0922 21.21 2:;. 29sii 22.61 24.88 .0822 19.09 20. (it; 1.0S77 20. 28 22.06 . on: '-2 21.46 •j;;. 1.1 .0987 22..;:; 24.86 . 0823 19.11 20. (19 L.0878 20. 30 22. OS .09:',:; 21. is 23.48 .0988 22.65 21.S9 . 0824 19.13 20. 71 1.0879 20. :!2 22. 1 1 .09:;! 21.50 23.51 . 0825 19.16 20. 71 1.088(5 20. 34 22.18 .0935 11.52 23.53 .09S9 22.67 24. 91 .0990 22. (19 24.94 .0826 111. IS 20. 76 LOSS] 20. 37 22.1(1 . HIM; 21.54 2:;.:>(i .0991 22.71 21.9(1 .0827 19.20 21 >. 7!) 1.0SS2 10.39 22. 19 .0937 21.56 28.59 .0992 22. 7;; 21.99 .0828 19.22 20. si l.oss:; 20. 11 22.21 .0988 21.59 2:;. (11 .0829 19.24 20.84 l.oss) 20. l:; 22. 21 .0939 21.111 2:1,. (11 .0830 19.26 20. stl L0885 20. 45 22. 2(1 .0940 21. 63 2:;. (id .0881 19.29 20.89 l.OSSf, 20. 17 22.29 .0911 21..;:. 23.69 .0882 19.31 20. 1)1 1.0887 20. 49 22.81 .0912 21. (17 2:;. 71 .0883 19.83 20.111 L.0888 20. f>2 22. 34 .0943 21. (19 2:;. 71 .0834 19.86 20.96 1.0889 20. f) 1 22. :>,C, .0911 21.71 2:;. 7t; 19.37 20.99 1.0890 20.66 22. :',9 .09 If, 21.7:; 2:;. 79 ! 136 PRO VISIONAL METHODS FOE ANALYSIS OF FOODS. TABLE V. — Extract in wine. [According to Windisch.] Spe- cific gravity. Ex- tract. Spe- cific gravity. Ex- tract. Spe- cific gravity. Ex- tract. Spe- cific gravity. Ex- tract. Spe- cffic gravity. Ex- tract. Spe- cific gravity. Ex- tract. 1.0000 0.00 1.0065 1.68 1.0130 3.36 1.0195 5. 04 1.0260 6.72 1.0325 8.40 1.0001 0.03 1.0066 1.70 1.0131 3.38 1.0196 5. 06 1.0261 6.75 1.0326 8.43 1.0002 0.05 1. 0067 1.73 1.0132 3.41 1.0197 5.09 1. 0262 6.77 1.0327 s. 41; 1. 0003 0.08 1.0068 1.76 1.0133 3.43 1.0198 5.11 1.0263 6.80 1.0328 S. .18 1.0004 0.10 1.0069 1.78 1. 0134 3.46 1. 0199 5.14 1.0264 6.82 1.0329 8.51 1.0005 0.13 1.0070 1.81 1.0135 3.49 1. 0200 5.17 1.0265 6.85 1. 0330 8.53 1. 0006 0.15 1.0071 1.83 1.0136 3.51 1. 0201 5.19 1.0266 6.88 1. 0331 8.56 1.0007 0.18 1.0072 1.86 1.0137 3. 54 1. 0202 5.22 1.0267 6.90 1.0332 8.59 1.0008 0.20 1.0073 1.88 1.0138 3.56 1.0203 5.25 1.0268 6.93 1. 0333 8.61 1.0009 0.23 1.0074 1.91 1. 0139 3.59 1. 0204 5. 27 1. 0269 6.95 1. 0334 8. 64 1.0010 0.26 1.0075 1.94 1. 0140 3.62 1.0205 5.30 1. 0270 6.98 1.0335 8.66 1.0011 0.28 1.0076 1.96 1.0141 3.64 1.0206 5.32 1. 0271 7.01 1 . 0336 8.69 1.0012 0.31 1.0077 1.99 1.0142 3.67 1.0207 5.35 1.0272 7.03 1.0337 8.72 1.0013 0.34 1.0078 2.01 1.0143 3.69 1. 0208 5.38 1.0273 7.06 1.0338 8.74 1.0014 0.36 1.0079 2.04 1.0144 3.72 1. 0209 5.40 1. 0274 7.08 1. 0339 8.77 1.0015 0.39 1.0080 2.07 1.0145 3.75 1.0210 5.43 1.0275 7.11 1. 0340 8.79 1.0016 0.41 1.0081 2.09 1.0146 3.77 1.0211 5.45 1.0276 7.13 1. 0341 8.82 1.0017 0.44 1.0082 2.12 1.0147 3.80 1 0212 5.48 1.0277 7.16 1.0342 8.85 1.0018 0.46 1.0083 2.14 1.0148 3.82 1.0213 5.51 1. 0278 7.19 1.0343 8.87 1.0019 0.49 1.0084 2.17 1.0149 3.85 1.0214 5.53 1.0279 7.21 1. 0344 8.90 1.0020 0.52 1.0085 2.19 1.0150 3.87 1.0215 5.56 1.0280 7.24 1. 0345 8.92 1.0021 0.54 1.0086 2. 22 1.0151 3.90 1.0216 5.58 1.0281 7.26 1. 0346 s. '.»:» 1.0022 0.57 1.0087 2.25 1.0152 3.93 1.0217 5.61 1.0282 7.29 1.0347 8.97 1.0023 0.59 1.0088 2. 27 1,0153 3.95 1. 0218 5.64 1.0283 7.32 1.0348 9.00 1.0024 0.62 1.0089 2.30 1. 0154 3.98 1.0219 5.66 1.0284 7.34 1.0349 9. 03 1.0025 0.64 1.0090 2.32 1.0155 4.00 1.0220 5.69 1.0285 7.37 1.0350 9. 05 1. 0026 0.67 1.0091 2.35 1.0156 4.03 1.0221 5.71 1.0286 7.39 1. 0351 9.08 1.0027 0.69 1.0092 2.38 1.0157 4.06 1. 0222 5.74 1.0287 7.42 1. 0352 9.10 1. 0028 0.72 1.0093 2.40 1.0158 4.08 1.0223 5.77 1.0288 7.45 1. 0353 9.13 1.0029 0.75 1.0094 2.43 1. 0159 4.11 1. 0224 5.79 1. 0289 7.47 1. 0354 9.16 1.0030 0.77 1. 0095 2.45 1.0160 4.13 1.0225 5.82 1.0290 7.50 1.0355 9.18 1.0031 0.80 1.0096 2.48 1.0161 4.16 1.0226 5.84 1.0291 7.52 1. 0356 9.21 1.0032 0.82 1.0097 2.50 1.0162 4.19 1. 0227 5.87 1.0292 7.55 1. 0357 9.23 1.0033 0.85 1.0098 2.53 1.0163 4.21 1.0228 5.89 1.0293 7.58 1. 0358 9.26 1.0034 0.87 1. 0099 2.56 1.0164 4.24 1.0229 5.92 1. 0294 7.60 1.0359 9.29 1. 0035 0.90 1.0100 2.58 1.0165 4.26 1. 0230 5.94 1.0295 7.63 1.0360 9.31 1.0036 0.93 1.0101 2.61 1. 0166 4.29 1.0231 5.97 1.0296 7.65 1.0361 9.34 1.0037 0.95 1. 0102 2.63 1. 0167 4.31 1. 0232 6.00 1.0297 7.68 1. 0362 9.36 1.0038 0.98 1. 0103 2.66 1.0168 4.34 1.0233 6.02 1.0298 7.70 1.0363 9.39 1.0039 1.00 1. 0104 2.69 1.0169 4.37 1. 0234 6.05 1.0299 7.73 1.0364 9.42 1.0040 1.03 1.0105 2.71 1.0170 4.39 1. 0235 6.07 1.0300 7.76 1.0365 9.44 1.0041 1.05 1.0106 2.74 1.0171 4.42 1.0236 6.10 1. 0301 7.78 1. 0366 9.47 1.0042 1.08 1. 0107 2.76 1. 0172 4.44 1.0237 6.12 1.0302 7.81 1.0367 9.49 1.0043 1.11 1.0108 2.79 1.0173 4.47 1. 0238 6.15 1. 0303 7.83 1.0368 9.52 1.0044 1.13 1.0109 2.82 1, 0174 4.50 1. 0239 6.18 1.0304 7.86 1. 0369 9.55 1.0045 1.16 1. 0110 2.84 1.0175 4.52 1.0240 6.20 1. 0305 7.89 1. 0370 9.57 1,0046 1.18 1. 0111 2.87 1.0176 4.55 1. 0241 6.23 1.0306 7.91 1.0371 9.60 1.0047 1.21 1.0112 2.89 1.0177 4.57 1.0242 6.25 1.0307 . 7.94 1. 0372 9. 62 1.0048 1.24 1.0113 2.92 1.0178 4.60 1.0243 6.28 1. 0308 7.97 1. 0373 9.65 1.0049 1.26 1. 0114 2.94 1. 0179 4.63 1.0244 6.31 1.0309 7.99 1. 0374 9.68 1.0050 : .29 1.0115 2.97 1.0180 4.65 1. 0245 6.33 1.0310 8.02 1. 0375 9.70 1.0051 . 3*2 1.0116 3.00 1.0181 4.68 1.0246 6.-36 1.0311 8.04 1. 0376 9.73 1.0052 .34 1.0117 3.02 1.0182 4.70 1.0247 6.38 1.0312 8.07 1. 0377 9.75 1.0053 .37 1.0118 3.05 1. 0183 4.73 1.0248 6.41 1. 0313 8.09 1.0378 9.78 1.0054 .39 1.0119 3.07 1. 0184 4.75 1. 0249 6.44 1. 0314 8.12 1. 0379 9.80 1.0055 .42 1.0120 3.10 1.0185 4.78 1.0250 6.46 1. 0315 8.14 1.0380 9.83 1.0056 .45 1.0121 3.12 1.0186 4.81 1.0251 6.49 1.0316 8.17 1.0381 '.). S6 1 . 0057 .47 1.0122 3.15 1. 0187 4.83 1. 0252 6.51 1.0317 8.20 1.0382 9.88 1. 0058 .50 1. 0123 3.18 1.0188 4.86 1.0253 6,54 1.0318 8.22 1.0383 9.91 1, 0059 .52 1. 0124 3.20 1. 0189 4.88 1.0254 6.56 1. 0319 8.25 1.0384 '.». 113 1.0060 .55 1.0125 3.23 1.0190 4.91 1. 0255 6.59 1. 0320 8.27 1.0385 '.). % 1.0061 .57 i 1.0126 3.26 1.0191 4.94 1.0256 6.62 1.0321 8.30 1.0386 '.». «.»'.> 1. 0062 .60 j 1.0127 :',. 2s 1.0192 4.96 1.0257 6.64 1.0322 8.33 1. 0387 1(1.01 1.0063 .63 1.0128 3.31 1.0193 4.99 1.0258 6.67 1.0323 8.35 1. 0388 10. Ot 1.0064 .65 1.0129 3. 33 1. 0194 5.01 1.0259 6. 70 1.0324 8.38 1. 0389 10.06 REFERENCE TABLES. TABLE V. — Extract in whir — Continued. 137 Spe- cific gravity. Ex- tract. cilic gravity Ex- tract. Spe- cific gravity Ex- tract. Spe- cific gravity Ex- tract. Spe- cific gravity. Ex- tract. Spe- cific gravity Ex- tract. 1. 0390 10.09 1.0455 11.78 1.0520 13.47 1.0585 15.16 1.0650 16.86 1. 0715 18.56 1.0391 10. 11 1.0456 11. HI 1. 0521 13.49 1. 0586 15. 19 1.0661 16.88 1.0716 18.58 L.0392 10.14 1. 0457 11.83 1.0522 18.62 1. 0587 15. 22 1. 0652 16.91 1.0717 18.61 L.0398 10.17 1.0458 11.86 1. 0523 1:5.55 1.0588 15. 24 1.0653 16.94 1.0718 18.63 1. 0394 10.19 1.0459 11.88 1.0524 13.57 1.0589 15. 27 1.0654 16.96 1.0719 18.66 1.0395 10.22 1.0460 11.91 1. 0525 13.60 1.0590 15.29 1. 0655 16.99 1. 0720 18.69 1.0396 10.25 1.0461 11.94 1.0526 13.62 1.0591 15. 32 1. 0656 17.01 1.0721 18.71 1.0397 10.27 1.0462 11.96 1.0527 13. 65 1.0592 15. 35 1.0657 17.04 1.0722 18.74 1. 0398 10.30 1.0468 11.99 1.0528 13.68 1.0593 15.37 1.0658 17.07 1.0723 18.76 1. 0399 10.32 1.0464 12.01 1.0529 13.70 1.0594 15.40 1.0659 17.09 1. 0724 18.79 1.0400 10.35 1. 0465 12.04 1. 0530 13.73 1. 0595 15.42 1.0660 17.12 1.0725 18.82 1.0401 10.37 1.0466 12. 06 1.0531 13.75 1. 0596 15. 45 1.0661 17.14 1. 0726 18.84 1.0402 10.40 1.0467 12. 09 1.0532 13.78 1.0597 15. 48 1.0662 17.17 1.0727 18.87 1.0408 10.43 1.0468 12.12 1.0533 13.81 1.0598 15.50 1.0663 17.20 1.0728 18.90 1.0404 10.45 1.0469 12.14 1.0534 13.83 1.0599 15.53 1. 0664 17.22 1.0729 18.92 1.0405 10.48 1.0470 12.17 1. 0535 13.86 1.0600 15.55 1.0665 17.25 1.0730 18.95 1.0406 10.51 1.0171 12. 19 1.0536 13.89 1. 0601 15. 58 1.0666 17. 27 1.0731 18.97 1.0407 10.53 L.0472 12.22 1. 0537 13.91 1.0602 15.61 1.0667 17.30 1.0732 19.00 1.0408 10.56 1.0473 12.25 1.0538 13.94 1.0603 15.63 1.0668 17.33 1.0733 19.03 1.0409 10.58 1.0474 12.27 1. 0539 13. 96 1.0604 15.66 1.0669 17.35 1. 0734 19.05 1.0410 10.61 1.0475 12.30 1.0540 13.99 1.0605 15.68 1. 0670 17.38 1. 0735 19.08 1.0411 10.63 1.0476 12.82 1.0541 14.01 1.0606 15.71 1.0671 17.41 1.0736 19.10 1.0412 10.66 1.0177 12. 35 1.0542 14.04 1.0607 15.71 1. 0672 17.43 1.0737 19.13 1.0413 10.69 1.0478 12.38 1.0643 16.07 1.0608 16.76 1.0673 17.46 1.0738 19.16 1.DI1I 10.71 1.0479 12.40 1.0544 14.09 1.0609 15.79 1.0674 17.48 1.0739 19.18 1.0415 10.74 1.0480 12.43 1.0545 1 1.12 1.0610 15. 81 1.0675 17.51 1.0740 19.21 L0416 10.76 1.0481 i-j. i:. 1.0646 11.11 1.0611 15.84 1.067*) 17.54 1.0711 19.23 1.0117 10.79 L.0482 12.48 1. 0547 11.17 1.0612 15.87 1.0677 17.66 1.0742 19. 26 L.0418 10.82 1.0483 12.51 1.0548 14.20 1.0613 15.89 1.0678 17. ;•«.» 1.0743 19. 29 1. 0419 10.84 1.0484 12.53 1.0649 14.22 1.0614 15.92 1.0679 17.62 1. 0744 19.31 L0420 10.87 1.0485 12.56 1.0550 14.25 1.0615 15.94 1.0680 17.64 1. 0745 19.34 1.0421 10.90 1.0486 12.58 1.0551 L4.28 1.0616 15.97 1.0681 17.67 1.0746 19.37 1.0422 10.92 1.0487 12.61 1.0552 14.30 1.0617 16.00 1.0682 17.69 1. 0747 19.39 1.0423 10.95 1.0488 12.64 1.0553 14.33 1.0618 16.02 1.0683 17.72 1. 0748 19.42 1.0424 10.97 1.0489 12.66 1.0554 14.35 1.0619 16.05 1.0684 17.75 1.0749 19.44 1.0125 11.00 1.0490 12.69 1.0555 14.38 1.0620 16.07 1.0685 17.77 1. 0750 19.47 L.0426 11.03 1.0491 12.71 1.0556 11. 11 1.0621 16.10 1.0686 17.80 1.0751 19.50 1.0427 11.05 1.0492 12.74 1.0557 1 1. i:: 1.0622 16.13 1.0687 17.83 1.0752 19. 52 1.0428 11.08 1. 0493 12.77 1.0558 11. 10 1.0623 16.15 1.0688 17.85 1. 0753 19.66 1. 0429 11.10 1.0494 12.79 1.0559 1 1. is 1.0624 16.18 1.0689 17.88 1.0754 19.58 1.0430 11.13 1. 0495 12.82 1.0560 11.51 1. 0625 16.21 1.0690 17.90 1.0755 19.60 1 . 0 1151 1 1 . 1 :. 1.04% 12.84 1.0561 M.5| 1.0626 16.23 1.0691 17.93 1.0756 19.63 1.0482 11.18 1.0497 12.87 1. 0562 14.56 1.IMJ27 16.26 1.0692 17.95 1.0757 19.65 1.0433 11.21 1.0498 12.90 1.0563 II.. v.i 1.0628 16.28 1.0693 17.98 1.0758 19.68 1. 0434 11.23 1.0499 12. 92 1.0564 14.61 1.0629 16.31 1.0694 18.01 1.0759 19.71 1.0435 11. 26 1.0500 12.95 1.0565 14.64 1. 0630 16.33 1.0695 18.03 1.0760 19.73 i.nr.t; 1 1 . 2S 1.0501 12.97 1.0566 14.67 1.0631 16.36 L.0696 18.06 1. 0761 19.76 1. 0487 11.31 1.0502 13.00 1.0567 14. 09 L.0632 16. 39 1.0(597 18.08 L.0762 19.79 1.0438 11.34 1.0503 13. 03 L0668 14.72 1.0633 16.41 1.0698 18.11 1.0763 19.81 1.0489 11.36 1.0504 18.06 1.0569 14.74 1.0634 16. 44 1.0699 18.14 1.0764 19.84 1. 0440 11.39 1.0505 13.08 1.0570 11.77 1.0635 16.47 1.0700 18.16 1. 0765 19.86 1.0111 11.42 1.0506 13.10 1. 0571 11. SI) 1.0686 16.49 1.0701 18.19 1. 07(!(; 19.89 1.0442 11.44 1.0507 L8.18 1. 0572 14,82 1.0637 16. 52 1.0702 18.22 1. 0767 19.92 1. 0443 11. 17 1.0508 13.16 1.0573 11. S5 1.0638 16.54 1.0703 18.24 1.0768 19.94 1.0444 1 1 . I'.i 1.0509 13.18 1. 0574 1 1.S7 1.0639 16.57 1.0704 18.27 1.0769 19.97 1.0445 11.52 1.0510 13.21 1.0575 14.90 1.0640 16.60 1.0705 18.30 1.0770 20.00 1.0446 11.66 1.0511 13.23 1. 0576 14.93 1.0641 16.62 1.0706 18.32 1. 0771 20.02 1.0447 1 1 . 57 1.0512 13.26 1. 0577 14.95 1.0642 16.66 1.0707 18. 35 1.0772 20.05 1.01 IS 11.60 1.0513 13.29 1.0578 14.98 1.0643 16.68 1.0708 18.87 1. 0773 20.07 1.0449 11.62 1.0614 13.31 1.0579 15.00 1.0644 16.70 1.0709 18.40 1. 0774 20.10 1.0460 11.68 L0616 13.34 1.0580 15.03 1.0645 16.73 1.0710 is. IM 1 . 0775 20.12 Loir,] 11. (is 1.0616 L8.86 1.0581 16.08 1.0(1 If, 16.75 1.0711 18.45 1.077(5 20.15 1.0462 11.70 1.0617 L8.89 1.0582 15.08 1.0647 16.78 1.0712 18.48 1. 0777 20.18 l.o i:.:; LI. 78 1.0618 13.42 1.0583 15.11 1. 0648 16.80 1.0713 18.50 1.077s 20.20 1.0454 1 1 . 7.-, 1.0519 13.44 1.0584 15. 14 1.0649 16.88 1.0714 18.53 1. 0779 20.23 138 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. TABLE V. — Extract in urine — Continued. Spe- cific gravity. Ex- tract. Spe- cific gravity. Ex- tract. Spe- cific gravity. Ex- tract. Spe- cific gravity. Ex- tract. Spe- cific gravity. Ex- tract, Spe- cific gravity. Ex- tract. 1. 0780 20.26 1.0845 21.96 1. 0910 23.67 1. 0975 25.38 1. 1040 27.09 1. 1105 28.81 1. 0781 20.28 1. 0846 21.99 1. 0911 23. 70 1.0976 25. 41 1.1041 27.12 1.1106 28.83 1. 0782 20.31 1.0847 22. 02 1. 0912 23.72 1.0977 25.43 ; 1. 1042 27.15 1.1107 28.86 1.0783 20.34 1.0848 22. 04 1. 0913 23.75 1.0978 25.46 i 1. 1043 27.17 1. 1108 28.88 1.0784 20.36 1. 0849 22.07 1. 0914 23.77 1.0979 25.49 i 1. 1044 27.20 1. 1109 28.91 1.0785 20.39 1.0850 22.09 1.0915 23.80 1.0980 25.51 1.1045 27.22 1. 1110 28.94 1.0786 20.41 1.0851 22.12 ! 1. 0916 23.83 1. 0981 25.54 1.1046 27.25 1. 1111 28.96 1.0787 20.44 1. 0852 22. 15 1.0917 23.85 1.0982 25. 56 1. 1047 27. 27 1.1112 28.99 1. 0788 20.47 1.0853 22.17 1. 0918 23.88 1. 0983 25.59 1.1048 27.30 1. 1113 29.02 1. 0789 20.49 1.0854 22.20 1. 0919 23.91 1.0984 25.62 I 1. 1049 27.33 1. 1114 29.04 1.0790 20.52 1.0855 22.22 1.0920 23.93 1. 0985 25.64 1.1050 27.35 1. 1115 29.07 1. 0791 20.55 1.0856 22. 25 1. 0921 23.96 1.0986 25.67 1. 1051 27.38 1. 1116 29. 09 1. 0792 20.57 1.0857 22. 28 1.0922 23.99 1. 0987 25.70 1. 1052 27.41 1. 1117 29. 12 1.0793 20.60 1.0858 22. 30 1. 0923 24.01 1. 0988 25. 72 1.1053 27.43 1.1118 29.15 1. 0794 20.62 1.0859 22.33 1. 0924 24.04 1. 0989 25.75 1.1054 27.46 1. 1119 29.17 1.0795 20.65 1.0860 22.36 1. 0925 24.07 1. 0990 25.78 1. 1055 27.49 1. 1120 29.20 1. 0796 20.68 1.0861 22.38 1.0926 24.09 1.0991 25.80 1. 1056 27.51 1. 1121 29.23 1.0797 20.70 1.0862 22.41 1.0927 24.12 1.0992 25.83 1 1. 1057 27.54 1. 1122 29.25 1. 0798 20. 73 1. 0863 22.43 1.0928 24.14 1.0993 25. 85 1.1058 27.57 1.1123 29.28 1.079S 20.75 1.0864 22.46 1.0929 24. 17 1.0994 25.88 1. 1059 27. 59 1.1124 29.31 1.0800 20.78 1. 0865 22.49 1.0930 24.20 1.0995 25.91 1. 1060 27.62 1. 1125 29.33 1.0801 20. 81 1.0866 22.51 1.0931 24. 22 1. 0996 25. 93 1. 1061 27.65 1. 1126 29. 36 1. 0802 20. 83 1.0867 22.54 1.0932 24.25 1.0997 25.96 1. 1062 27.67 1. 1127 29.39 1.0803 20.86 1. 0868 22.57 1.0933 24.27 1. 0998 25. 99 1. 1063 "7.70 1. 1128 29.41 1. 0804 20.89 1.0869 22.59 1. 0934 24.30 1.0999 26. 01 1. 1064 2.. 72 1. 1129 29.44 1. 0805 20.91 1. 0870 22.62 1.0935 24.33 1.1000 26.04 \. 1065 27.75 1.1130 29.47 1.0806 20.94 1.0871 22. 65 1. 0936 24. 35 1.1001 26. 06 1. 1066 27.78 1. 1131 29.49 1.0807 20.96 1.0872 22.67 1. 0937 24.38 1.1002 26.09 1.10t>7 27.80 1. 1132 29. 52 1. 0808 20.99 1.0873 22. 70 1. 0938 24.41 1.1003 26.12 1.1068 27.83 1.1133 29.54 1.0809 21.02 1.0874 27.72 1.0939 24.43 1.1004 26.14 1.1069 27.86 1. 1134 29. 57 1.0810 21.04 1. 0875 22.75 1.0940 24.46 1.1005 26.17 1. 1070 27.88 1.1135 29.60 1. 0811 21.07 1.0876 22.78 1.0941 24.49 1.1006 26.20 1. 1071 27.96 1.1136 29.62 1.0812 21.10 1.0877 22.80 1. 0942 24. 51 1.1007 26.22 1. 1072 27.03 1. 1137 29.65 1. 0813 21.12 1. 0878 22. 83 1.0943 24.54 1.1008 26.25 1.1073 27.96 1. 1138 29.68 1.0814 21.15 1. 0879 22.86 1.0944 24.57 1.1009 26.27 1. 1074 27. 99 1. 1139 29.70 1.0815 21.17 1.0880 22.88 1.0945 24.59 1. 1010 26.30 1. 1075 28.01 1.1140 29.73 1. 0816 21.20 1. 0881 22.91 1. 0946 24.62 1. 1011 26.33 1.1076 28.04 1.1141 29.76 1.0817 21.23 1.0882 22. 93 1. 0947 24.64 1. 1012 26. 35 1. 1077 28.07 1. 1142 29.78 1. 0818 21. 25 1.0883 22.96 1.0948 24.67 1.1013 26.38 1.1078 28.09 1.1143 29.81 1. 0819 21.28 1.0884 22.99 1. 0949 24.70 1. 1014 26.41 1. 1079 28.12 1. 1144 29.83 1. 0820 21.31 1. 0885 23.01 1.0950 24.72 1. 1015 26.43 1. 1080 28.15 1.1145 29.86 1.0821 21. 33 1. 0886 23.04 1.0951 24.75 1. 1016 26.46 1. 1081 28.17 1. 1146 29.89 1.0822 21.36 1. 0887 23.07 1. 0952 24.78 1. 1017 26.49 1. 1082 28. 20 1. 1147 29.91 1. 0823 21.38 1. 0888 23.09 1.0953 24.80 1. 1018 26.51 1.1083 28.22 1.1148 29.94 1. 0824 21, 41 1.0889 23.12 1.0954 24.83 1.1019 26.54 1.1084 28.25 1. 1149 29.96 1.0825 21.44 1. 0890 23.14 1.0955 24. 85 1. 1020 26.56 1. 1085 28.28 1. 1150 29.99 1.0826 21.46 1. 0891 23. 17 1.0956 24.88 1. 1021 26. 59 1.1056 28.20 1.1151 30.02 1. 0827 21.49 1.0892 23.20 1.0957 24.91 1. 1022 26.62 1. 1087 28. 33 1. 1152 30.04 1. 0828 21.52 170893 23. 22 1. 0958 24.93 1. 1023 26.64 1.1088 28. 36 1.1153 30.07 1.0829 21.54 1. 0894 23.25 1. 0959 24.96 1. 1024 26.67 1. 1089 28.38 1. 1154 30.10 1.0830 21.57 1. 0895 23.28 1.0960 24.99 1. 1025 26.70 1. 1090 28.41 1.1155 30.13 1. 0831 21. 59 1.0896 23.30 1. 0961 25.01 1.1026 26.72 1. 1091 28.43 1.1156 30.15 1. 0832 21.62 1.0897 23.33 1.0962 25.04 1.1027 26.75 1.1092 28. 46 1.1157 30.18 1. 0833 21.65 1.0898 23.35 1.0963 25.07 1. 1028 26.78 1.1093 28. 49 1. 1158 30.21 1.0834 21.67 1.0899 23.38 1.0964 25.09 1. 1029 26.80 1.1094 28.51 1. 1159 30.23 1.0835 21.70 1.0900 23.41 1.0965 25.12 1. 1030 26.83 1. 1095 28.54 1.0836 21. 73 1.0901 23.43 1. 0966 25. 14 1. 1031 26. 85 1.1096 28.57 1.0837 21. 75 1.0902 23.46 1. 0967 25. 17 1. 1032 26.88 1. 1097 28.59 1.0838 21.78 1.0903 23.49 1. 0968 25.20 1. 1033 26.91 1. 1098 28.62 1. 0839 21.80 1.0904 23.51 1.0969 25.22 1. 1034 26. 93 1.1099 28.65 1.0840 21. 83 1.0905 23.54 1. 0970 25.25 1.1035 26.96 1.1100 28.67 1. 0841 21.86 1.0906 23. 57 1.0971 25.28 1. 1036 26.99 1. 1101 28. 70 1.0842 21.88 1.0907 23.59 1. 0972 25. 30 1. 1037 27. 01 1. 1102 28.73 1.0843 21.91 1.0908 23.62 1.0673 25.33 1. 1038 27. 04 1.1103 28.75 1. 0844 21.94 1.0909 23.65 1.0974 25. 36 1. 1039 27.07 1.1104 28.78 REFERENCE TABLES. 139 TABLE VI. — Relation <>j hrir, gpeciftc gravity, «n% 8.1 21.1 1.0882 11.7 .7 1.0066 0.9 8.2 .0827 4.55 11.7 1.0600 8.16 21.2 1.0886 11.7 .8 1.0070 1.0 8.3 .0331 4.6 14.8 1.0604 s. 2 21.3 1.0891 11.8 .9 1.0074 1.05 8.4 .0835 4.7 14.9 1.0609 8.3 •_'l. 1 l . os'.tn 11.8 2.0 1.0077 1.1 8.5 .0339 4.7 16. Q L0818 s.:; 21.5 1.0900 11.9 2.1 1.0081 1.2 8.6 . 0343 4.8 lf,.l 1.0617 8.4 21.6 1.0904 11.95 2.2 1.0085 1.2 8.7 . 0:5 17 4.8 16.2 L0621 s. 1 21.7 1.0909 12.0 2.3 1.0089 1.3 8.8 .0351 4.9 L6.8 1.0626 21.8 1.0914 12.05 2.4 1.0093 1.3 8.9 .0855 4.9 15. i 1.0630 8.5 21.9 1.0918 12.1 2.5 1.0097 •1.4 9.0 . 035'J 5.0 16.6 L.0684 8.6 22.0 1.0'. 12:; 12.2 2.6 1.0101 1.4 9.1 1.0864 5.05 16. 6 1.0639 8.65 22.1 1.0927 12.2 '2.7 1.0105 1.5 9.2 1.0308 5.1 16.7 L.0648 8.7 •2-2. -2 1.0932 12,8 2.8 1.0109 1.55 9.3 1.0372 5.2 15.8 L0647 8.8 22.3 1.0936 12.3 2.9 1.0113 Li 9.4 L.0876 5.2 16. 9 L.0652 8.8 22.4 1.0941 12.4 3.0 1.0117 1.7 9.5 1.0380 5.3 16.0 MM;:*; 8.9 22.5 1.0945 12.4 3.1 1.0121 1.7 9.6 1.0384 5.3 16.1 1.0660 8.9 •2-2. 6 1.0950 12.5 3.2 1.0125 1.8 9.7 1.0388 5.4 16.2 1.0665 9.0 22. 7 1.0954 12.55 3.3 1. 0129 1.8 11. S .0393 5.4 16.3 1.0669 9.0 22. s 1 . Oit:><.l 12.6 3.4 1.0133 1.9 9.9 .0897 5.5 Hi. 1 L.0874 '.M 22. '.» 1.0964 12.7 3.5 1. 0137 1.9 10.0 .0401 r,. .vi 18.6 1.0678 9.1 28.0 1.0968 12.7 3.6 .0141 2.0 10.1 .0405 5.6 16.6 1.0682 9.2 23.1 1.0973 12. 8 3.7 .0145 2.0 10.2 .0409 5.7 it;. 7 1.0687 '.i. 25 23.2 1.0977 12.8 3.8 .0149 2.1 10.3 .0413 5.7 L6.8 1,0691 9.3 23.3 1.0982 12.9 3.9 .0153 2.2 10.4 .0418 5. s 16.9 .0696 '.». 1 23.4 1.0986 12.9 4.0 .0157 2.2 10.5 .0422 5.8 17.0 .0700 '.i. 1 23.5 1.0991 13.0 .1 .0161 2.3 10.6 .4426 5.9 17.1 .0704 9.5 2::. 6 1.0996 13.0 .2 .0165 2.3 10.7 .0430 5.9 L7.2 .0709 23.7 1.1000 13.1 .3 .0169 2.4 10.8 .0434 6.0 17.:; .0718 9.6 23.8 1.1005 13.15 .4 .0173 2.4 10.9 .0489 6.05 17.4 .0717 9.6 23.9 1.1009 13.2 .5 .0177 2.5 11.0 .0448 6.1 17.5 .0722 9.7 24.0 1. 1014 13.3 .6 .0181 2.6 11.1 .(HI7 8.2 17.6 .0726 '.). 7.'. 21. 1 1.1019 13.3 .7 .0185 2. (i 11.2 .0451 6.2 17.7 .0730 9.8 24.2 1.102:5 l:;. 1 .8 .0189 2.7 11.3 .0455 6.3 17.8 .0735 9.9 24.8 1. 102H 13.4 .9 .0193 •J.7 11.4 .0459 6.3 17.9 . 0739 '.». '.' 21. 1 1.1032 13.5 5.0 .0197 2.8 11.5 .0464 6.4 ls.it .0744 10.0 24.5 1.1037 13.5 5.1 . 0201 2.8 1 1 . <; .0468 (i. i 18.1 .07 is 10.0 34.6 1.1042 13.6 . 0205 2.9 11.7 .0472 6.5 18.2 .117:.:; 10.1 24.7 1.1046 13.6 5.8 .0209 2.9 11.8 .di7«; 18.3 .0757 10.1 24.8 1.1061 13.7 :». i .0213 3.0 11.9 .0481 6.6 is. 1 .07C.1 in. 2 24.9 1.1056 13. 75 .0217 8.0 12.0 .0485 6.7 18.6 .0786 10.2 25. o 1.1080 13.8 5. i; .0221 3.1 12.1 .0489 C..7 18.6 . 0770 10.3 26, 1 1.1065 13.9 ."..7 . 0225 :'-. -1 12.2 .0493 6.8 18.7 .0775 10. 35 25. 2 1.1070 13.9 5. x .0229 3.2 12.8 .0497 li. s 18.8 .(I77'.i Ki. 1 2.-). 3 1.1071 14.0 5. '.) .0233 8.3 12.4 .0502 6. '.» 18.9 .0783 10.5 •jr.. i L.1079 11.0 6.0 . 02:57 3.3 12.6 . 0506 (i. y ly.o .0788 10.5 25. r. 1.1083 11.1 6.1 .024] :;. 1 12. C .0610 7.0 1'.!. 1 .0792 10. C, 25. t; 1.1 OSS 11.1 6.2 .0245 12.7 .0514 7.0:. 19. 2 .0797 10.6 25. 7 1.1098 14,2 6.3 .0249 3.5 12.8 .0519 7. 1 L9.8 .0801 1(1.7 25. s i. ui'.>7 14,2 «',. 1 . 02;.:! 3.6 12.9 .0628 7.2 I1.!, i .0806 10.7 25. '.< 1.1102 n.:; 6.5 1.0257 8.1 13.0 .0527 7.2 19. 6 .0810 10. s 26. 0 1.1107 14.35 140 PROVISIONAL METHODS FOB ANALYSIS OF FOODS. TABLE VI. — Relation of brix, specific gravity, and Baumi — Continued. Per cent of sugar. Specific gravity. Degree Baum6. Per cent of sugar. Specific gravity. Degree Baume. Per cent of sugar. Specific gravity. Degree Baume\ Per cent of sugar. Specific gravity. Degree Baume. •20. 1 1.1111 14.4 32.6 . 1422 17.9 39.1 1. 1748 21.4 45.6 .2088 24.9 2. -4 . 2077 24.8 51.9 .2433 28.2 32.5 1.1417 17.9 39.0 .1743 21.4 45. 5 1.2083 24.8 52.0 .2439 28.2 REFERENCE TABLES. 141 TABLE VI. — Relation of brix, specific gravity, and Baume — Continued. Per fl'Ilt of sugar Specific gravity. Degree Baumc. Per cent of sugar Specific gravity. Degree BaumC- Per cent of sugar Specific gravity. Degree Baume. Per cent of sugar Spccilic gravity. Degree Baumg. 52. 1 1.2444 28.3 58.6 1.2816 31.6 65.1 1.3205 34.95 71.6 1.3610 38.2 52. 2 1.2450 28.3 58.7 1.2822 31.7 65.2 1.3211 35.0 71.7 1.3616 38.2 52. 3 1 . 2455 28.4 58.8 1.2828 31.7 65.3 1.3217 35.05 71.8 1.3623 38.2 52.4 1.2461 28.4 58.9 1.2834 31.8 65.4 1.3223 35.1 71.9 1.3629 38.3 52.5 1.2467 28.5 .")'.». 0 1.2840 :;i.s:, 65.5 1.3229 35.15 72.0 1.3635 38.3 52.6 1. 2472 28.5 59.1 1.2845 31.9 65.6 1.3235 35.2 72.1 1.3642 38.4 52. 7 1. 2478 28.6 59.2 1.2851 31.95 65.7 1.3241 35.25 72.2 1.3648 38.4 62.8 1.2483 28.65 59.3 1.2857 32.0 65.8 1.3247 35.3 72.3 1.3655 38.5 5v. 9 1.2489 28.7 59.4 1.2863 92.06 65.9 1.3253 35.35 72.4 1.3661 38.5 63.0 1.2495 28.75 59.5 1.2869 32.1 66.0 1. 3260 35.4 72.5 1.3667 38.6 53. 1 1.2500 28.8 59.6 1.2875 32.15 66.1 1. 3266 35.4 72.6 1.3674 38.6 M. '2 1.2506 28.85 59.7 1.2881 :«. '2 66.2 1.3272 :{.-). :> 72.7 1.3680 38.7 63.3 1.2512 | 28.9 59.8 1.2887 32.3 66.3 1.3278 35.5 72.8 1.3687 38.7 53.4 1.2517 28.9 59.9 1.2893 32.3 66.4 1.3285 35.6 72.9 1.3693 38.8 53. 5 1.2523 29.0 60.0 1.2898 32.4 66.5 1.3291 35.6 73.0 1.3699 38.8 53. (i 1.2529 i 29.1 60.1 1.2904 ' 32.4 66.6 1.3297 a=i.7 73.1 1. 3705 38.9 53.7 1.2534 29.1 60.2 1. 2910 32. 5 . 66.7 1 . :wtw 35.7 73.2 1.3712 38.9 63.8 1.2540 29.2 60.3 1.2916 32.5 66.8 1.3309 35.8 73.3 1.3719 39.0 53.9 1.2546 29.2 60.4 1.2922 32.6 66.9 1.3315 35.8 73.4 1.3725 39.0 54.0 1.2551 29.3 60.5 1.2928 32.6 67.0 1.3322 35.9 73.5 1. 3732 39.1 64.1 1.2557 ! 29.3 60.6 1.2934 32.7 67.1 1.3327 35.9 73.6 1.3738 39.1 64.2 1.2563 '*). 1 60.7 1.2940 32.7 67.2 1.3334 36.0 73.7 1.3745 39.2 64.3 1.2568 29.4 60.8 1.2946 32.8 67.3 [.8340 36.0 73.8 1.3751 39.2 54.4 1 . 257 1 29.5 60.9 1.2952 82.8 67.4 1.3346 :;<;. i 73.9 1.3757 39.3 54.5 1.2580 29.5 61.0 1.2956 32.9 67.5 1.3*52 36.1 74.0 1.3764 39.3 54.6 1.2585 29.6 61.1 1.2%4 32.9 67.6 1.3359 36.2 74.1 1.3770 39.4 64.7 1.2591 29.6 61.2 1.2970 33.0 (17.7 1.3365 36.2 74.2 1.3777 39.4 64.8 1.2597 29.7 61.3 1.2975 33.0 67.8 1.3371 36.3 74.3 1.3783 39.5 64.9 1.2602 29.7 61.4 1.2981 33.1 67.9 1.3377 36.3 74.4 1.3790 39.5 55.0 1.2608 29.8 61.5 1.2987 33.1 68.0 1.3384 36.4 74.5 1.3796 39.6 55. 1 1. 2614 29.8 61.6 1.2993 33.2 68.1 1.3390 36.4 74.6 1.3803 39.6 f>f>. 2 1.2620 29.9 61.7 1.2999 33.2 68.2 1.33% 36.5 74.7 L.8808 39.7 55.3 1.2625 29.9 61.8 1.3005 33.3 68.3 1. 3402 36.5 74.8 1.3816 39.7 65 4 1.2631 30.0 61.9 1.3011 :«. :; 68.4 1.3408 36.6 74.9 1.3822 39.8 65.5 1.2637 30.05 62.0 1.3017 33.4 68.5 1.3415 36.6 75.0 1.3828 39.8 65.6 L2642 30.1 til'. 1 1.3023 33.4 68.6 1.3421 36.7 75.1 1.3835 39.9 55.7 1.2648 30. 15 62.2 L.3029 33.5 68.7 1.3427 36.7 75.2 1.3842 39.9 f>:>. s 1.265* 30.2 . :j 1.3035 :;:>. ;, 88,8 1.3433 36.8 75.3 1.3848 40.0 55.9 1.2660 30.25 62.4 1.3041 33.6 68.9 1.3440 36.8 75.4 1.3855 40.0 56.0 1.2665 30.3 62.5 1.3047 33.6 69.0 1.3446 36.9 75.5 1.3861 40.1 66.1 1.2671 30.4 62.6 1.3053 33.7 69.1 1.3452 36.9 75.6 1.3868 40.1 56.2 1. 2677 30.4 62.7 1.3059 33.7 1.3458 37.0 75.7 1.3874 40.2 56.3 1.2683 30.5 • 12. s 1.3065 33.8 69.' 3 1.3465 37.0 75.8 1.3880 • 40.2 66.4 1.26H8 30.5 62.9 1.3071 33.8 69.4 1.3471 37.1 75.9 1.3887 40.3 56.5 1.2694 30.6 63.0 1.3077 33.9 69.5 1.3477 37.1 76.0 1.3894 40.3 56.6 1.2700 30.6 63.1 1.3083 33.9 69.6 1.3484 37.2 76.1 1.3900 40.4 56.7 1.2706 30.7 63.2 1.3089 34.0 69.7 1.3490 37.2 76. 2 1.3907 40.4 56.8 1. 2712 30.7 <;:i « 1.3095 34.0 99.8 1.3496 37.3 76. 3 1.3913 40.5 66.9 1.2717 30.8 63.4 1.3101 34.1 69.9 1.3502 37.3 76.4 1.3920 40.5 67.0 1.2723 30.8 63.5 1. 3107 34.1 70.0 1.3509 37.4 76.6 1.3926 40.6 57.1 1. 2729 30.9 IN',. C> 1.3113 34.2 70.1 1. 3515 37. 1 76.6 1.3933 40.6 67.2 1 . 27:!f> 30.9 63.7 1.3119 34.2 70.2 1.3521 37.5 76.7 1 . WHO 40.7 57.3 L.2740 31.0 63.8 L.8126 34.3 70.3 1.3528 37. 5 76.8 1.3916 - 40.7 67.4 1. 2746 31.0 63.9 L.8182 34.3 70.4 1.3534 37.6 76.9 1.3953 40.8 57.5 1.2752 31.1 64.0 L8188 34.4 70.5 1.3540 37.6 77.0 1.3959 40.8 67.6 1.2758 31.1 HI.] 1.3144 34.4 70.6 1.3546 37.7 i 77.1 1.3966 40.8 6'. 7 1.2764 31.2 64.2 1.3150 34.5 70.7 1.3553 37.7 77.2 1. 3972 40.9 67*8 1.2769 31.2 64.3 1.3156 34.5 70.8 1.3559 37.8 77.3 1.3979 41.0 67.9 1.2775 31.3 64.4 1.3162 34.6 70.9 1 . :i.v,5 37.8 77.4 1.3986 41.0 68.0 1.2781 31.3 '64.5 1.3168 34.6 71.0 1.3572 37.9 77.5 1.3992 41.0 58.1 1.2787 31.4 64.6 1.3174 34.7 71.1 1.3578 37.9 77.6 1.3999 41.1 68.2 1 . 27'.»:{ 31.4 84.7 1.3180 34.7 71.2 I . :;;>x:> 38.0 77.7 1.4005 41.1 68.3 1.2799 31.5 84.8 l.Misr, 34.8 71.3 1.3591 38.0 77.8 1.4012 41.2 68.4 1.2804 31.5 64.9 1.3192 34.8 71.4 1. 3597 38.1 77.9 1. 4019 41.2 1.2810 31.6 65.0 1. 3198 34.9 71.5 1.3604 38.1 78.0 1.4025 41.3 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. TABLE VI. — Relation of brix, specific gravity, and Baume — Continued. Per Per Per Per cent of Specific gravity. Degree Baum6. cent of Specific gravity. Degree Baume. cent of Specific gravity. Degree Baume. cent of Specific gravity. Degree Baume. sugar sugar. sugar. sugar. 78.1 1.1032 41.3 80.1 1.4165 42. :^ 82.1 1.4300 43.3 84.1 1. 4437 44.2 78.2 1. 4039 41. 1 80.X2 1.4172 42.3 82.2 1.4307 43.3 84.2 1.441:; 44.3 78.3 1.4045 41.4 80.3 1.4179 42.4 82.3 1.4314 43.4 84.3 1. 44,50 44.3 78.4 1. I0.rv_> 41 . 5 80.4 ! . 1 1 85 42.4 82.4 1.4320 43.4 84.4 1.4457 44.3 78.5 1.4068 41.5 80.5 1. 4192 vi. r, 82.5 1.4327 43.5 "84.5 1.4464 44.4 78.6 .4065 11. (i 80.6 .4199 42. 5 82.6 1.4334 43.5 84. 6 1.4471 44.4 78.7 1.4072 41.6 80.7 .4205 42.6 82.7 1. 4341 43.5 84.7 1.4478 44.5 78.8 .4078 41.7 80.8 .4212 42.6 82.8 1.4348 43.6 84.8 1.4485 44.5 78.9 . 4085 41.7 80.9 .4219 42. 7 82.9 1.4354 43.6 84.9 1. 4492 44.6 79.0 .4092 41.8 81.0 . !•_>•_><; 42. 7 83.0 1. 4361 43.7 85.0 1.4498 44.6 79.1 .4098 41.8 81.1 .1232 12. s 83.1 1.4368 43.7 85.1 .4505 44.7 79.2 .4105 41.9 81.2 . 4239 12.8 83. 2 1.4375 43.8 85.2 .4512 44.7 79.3 1.4112 41.9 81.3 .4246 42.9 s:{. S 1.4382 43.8 85.3 .4519 44.8 79.4 1.4119 42.0 81.4 . IL>5:; 42. '.» 83.4 1.4388 43.9 85.4 . 452ti 44. S 79.5 1. 4125 42.0 81.5 .4259 43.0 83.5 1. 4395 43.9 85.5 .4533 44.9 79.6 1. 4132 42.1 81.6 .4266 43.0 83.6 1.4402 44.0 85.6 .4540 44.9 79.7 1. 4138 42.1 81.7 . 42J73 43.1 83.7 1.4409 44.0 85.7 .4547 45. 0 79.8 1.4145 42.2 81.8 .4280 43.1 83.8 1. 4416 44.1 85.8 .4554 45.0 79.9 1.4152 42.2 81.9 .4287 43.2 i 83.9 1.4423 44.1 85.9 .4561 45.1 80.0 1.4158 42.2 82.0 1.4293 43. 2 84.0 1.4430 44.2 86.0 .4568 45.1 TABLE VII. — Correction for the readings of fiat./ hi;/'* mccharometer, on account of temperature. TO BE SUBTRACTED FROM THE DEGREE READ. Temp. Ivr cent of sugar in solution. C. 0 5 10 15 20 25 :;o :•,:> 40 50 60 70 75 13 0.14 0.18 0.19 0.21 0.22 0.24 0.26 0.27 0. 28 0. 29 0.33 0.35 0.39 14 .12 .15 .16 .17 .18 .19 .21 .22 . 22 . 23 .26 .28 .32 15 .09 .11 .12 .14 .14 .15 .16 .17 .16 i .17 .19 .21 .25 16 .06 .07 .08 .09 .10 .10 .11 .12 . 12 . 12 .14 .16 .18 17 .02 .02 .03 .03 .03 .04 .04 .04 .04 .04 .05 .05 .06 TO BE ADDED TO THE DEGREE READ. 18 .02 .03 .03 .03 .03 \ .03 .03 .03 .03 .03 .03 .03 .02 19 .06 .08 .08 .09 .09 .10 .10 .10 .10 .10 .10 .08 .06 20 .11 .14 .15 .17 .17 .18 .18 .18 .19 .19 .18 .15 .11 21 .16 .20 .22 .24 .24 .25 .25 .25 .26 .26 .25 .22 .18 22 .21 .26 .29 .31 .31 .32 .32 .32 .33 .34 .32 .29 .25 23 ' .27 .32 .35 .37 .38 .39 .39 .39 .40 .42 . .39 .36 .33 24 .32 .38 .41 .43 .44 .46 .46 .47 .47 .50 .46 .43 .40 25 .37 .44 .47 .49 .51 .53 .54 .55 .55 .58 .54 .51 .48 26 .43 .50 . 54 .56 .58 .60 .61 .62 .62 .66 .62 .58 .55 27 . .49 .57 .61 .63 .65 .68 .68 .69 .70 .74 .70 .65 .62 28 .56 .64 .68 .70 .72 .76 .76 .78 .78 .82 .78 .72 .70 29 .63 .71 .75 .78 .79 .84 .84 .86 .86 .90 .86 .80 .78 30 .70 .78 .82 .87 .87 . 92 .92 .94 94 .98 .94 .88 .86 REFERENCE TABLES. TABLE VIII.— J///7m',s table for tin- ilffmiiiimtioH of dextrose. 143 Milli- grams of cop- per. Milli- i grams I of cu- prous oxid. Milli- grams of dex- trose. Milli- grams of cop- per. Milli- grams of cu- prous oxid. Milli- of dex- trose. Milli- grams of cop- per. Milli- grams Of cu- prous oxid. Milli- grams of dex- trose. Milli- grams i of cop- per. Milli- grams of cu- prous oxid. Milli- grams of dex- trose. 11 !•_'. i »;. 6 7(1 s5. t; •;s s 1 11 158.7 71.8 206 231.9 105.8 12 18.6 7. 1 77 stl. 7 :;'.i. :; 1 12 159.9 72. 3 207 233. 0 106.3 13 14.6 7. t> 7s s7. s :;!•. s 1 \:\ 1 161.0 72. 9 20S 284.2 106.8 1 I 1 5. s s. 1 7< ss. (,i id.:; 1 1 1 162. 1 73.4 209 2:;5. :; 107.4 18 10.9 s. i; SO 9: i 1 •to. s 145 163.2 73. 9 210 2:1,c>. I 107.9 16 18.0 9.0 si :n.2 41.8 in; 161. 1 71. 1 211 2:57. 6 108.4 17 19.1 9.5 82 92. :; ll.s 117 165.5 74.9 212 2:>s. 7 109.0 18 •jo.:; 10.0 88 98. 12. :; 148 166.6 75. 5 218 239. s 109. ft 19 21.1 10.5 si '.M.I; 42.8 149 167.7 76.0 211 210.9 110.0 •JO 22. ."> 11.0 86 95. 7 i:l. 1 150 16S.9 76.5 215 i 242. 1 110.6 •_M •_>;>_ ('» 11.5 86 %. s 4:i. '. 151 170.0 77.0 216 243. 2 111.1 22 24! 8 12.0 87 97.9 11. 1 152 171.1 77.5 217 244.3 111.6 23 25.9 12.5 99.1 11. 9 153 172.:; 78.1 218 245.4 112. 1 24 27.0 13.0 89 100.2 15. 1 151 178.4 78.6 219 246.6 112.7 25 28.1 18. 5 90 101.8 15.9 155 171.5 79.1 220 247.7 113.2 26 29. :> ll.ii 91 102. 1 16. 1 156 175.6 79.6 221 248.7 113.7 '27 30.4 11.5 92 103.6 46.9 157 176.8 80.1 222 249.9 114.3 28 :;i.:. 15.0 93 101.7 47.4 158 177.9 80.7 223 251.0 114.8 29 32.7 15.5 M 105.S 17.9 159 179.0 81.2 224 252.4 115.3 30 33.8 16.0 96 107.0 48.4 160 180.1 81.7 225 253.3 115.9 81 34.9 it;. 5 <„; Ids. l IS. 9 161 181.3 82.2 226 251. 1 116.4 32 36.0 17.0 ',17 109.2 49.4 162 182. 4 82.7 227 255. 6 116.9 33 f!7. "J 17. ft 96 111) ;; 19. 9 163 183. 5 83.3 228 256.7 117.4 :;i ;;s ;; 18.0 99 111.5 50. 1 164 184.6 s;;. .s 229 257. s 118.0 85 ;;'.». i is. 5 LOO 112.6 .50. 9 165 186.8 84.3 230 25s. 9 118.5 u K.I. 5 IS. 11 101 11:;. 7 51.4 166 186.9 84.8 2:;i 26(1. 1 119.0 37 11.7 19.4 102 114. 8 51.9 167 188.0 86. :: 261.2 119. 6 88 12. s 19.9 103 116.0 168 189.1 86. 9 2 W •'I'r' ;; 120.1 39 I:1,, '.i 20. I 101 117.1 52.9 169 190.3 86.4 2il 26:!. 1 120.7 in 1."). (I 20. 9 105 1 1 S. 2 53.5 170 191.4 86.9 235 261.6 121.2 11 it;. 2 21. 1 106 1 19.:; 51.0 171 192.5 87.4 286 265. 7 121.7 12 17.:; 21.9 107 120.5 51.5 172 193.6 87.9 237 266. s 1-22.3 18 is. 1 22.4 108 121.6 55. 0 178 194. 8 88.5 238 268.0 122.8 H 49.5 22. 9 109 122.7 55 5 174 195.9 89.0 239 269. 1 123.4 1") 50.7 23.4 110 L28.8 56.0 175 197.0 89.5 210 270.2 123.9 1C, 51.8 23.9 111 125.0 56. 5 176 198.1 90.0 241 271.3 124.4 17 62. '.» 24.4 112 126. 1 57. 0 177 199.3 90.5 242 272.5 125.0 is 54.0 24.9 113 127.2 57. 5 178 200.4 91.1 243 273.6 125. 5 49 55. 2 25. 1 111 128,3 58.0 179 201.5 91.6 211 274.7 126.0 50 56. 3 25.9 115 129.6 58.6 180 202.6 92.1 245 275.8 126.6 51 57. 1 26.4 IK; 130.6 59.1 181 203.8 92.6 246 277.0 127.1 52 58.5 26.9 117 181.7 59.6 182 204.9 93.1 247 278.1 127. 6 53 51). 7 27. 1 118 132. 8 60.1 183 206.0 93.7 248 279.2 128.1 M 60.8 27.9 119 134.0 60.6 184 207. 1 94.2 249 280.3 128.7 55 61.9 28.4 120 135.1 61.1 185 208.3 94,7 250 281.5 129.2 56 63.0 28. s 121 186.2 61.6 186 209.4 95. 2 251 282.6 129.7 57 64.2 29.3 122 i:;7. 1 62.1 187 210.5 95. 7 252 283.7 130.3 58 66, :; 29.8 123 138.5 62.6 188 211.7 96.3 253 284.8 130.8 59 66. 1 30.3 121 139.6 63.1 189 212. S 96. S 254 286.0 131.4 60 (17. (i 30.8 125 140.7 63.7 190 218.9 97. 3 255 287.1 131.9 C,l 6s. 7 31.3 126 141.9 64.2 191 215.0 97.8 256 288.2 132.4 62 69. s 81.8 127 M:;. o 64.7 192 216. 2 98.4 257 289.3 133.0 63 70.9 32.3 128 144.1 65. 2 193 217.3 98.9 258 290.5 133.5 64 72: 1 32.8 129 115.2 65. 7 194 218.4 99.4 259 291.6 134.1 65 73.2 33.3 130 1 16. 1 66.2 195 219.5 100.0 260 292.7 134.6 66 74.3 33.8 131 147. 5 66.7 196 220.7 100.5 261 293.8 135.1 (17 75.4 34.3 1.72 148.6 67.2 197 221.8 101.0 262 295.0 135.7 68 76.6 84.8 188 149.7 67.7 198 222.9 101.5 263 296.1 136.2 M 77.7 85.8 184 1-50.9 68.2 199 224.0 102. 0 264 ?97.2 136.8 70 7s. s 86. 8 186 152.0 68.8 200 225.2 102.6 265 29S. 3 137.3 71 79. '.i 36.8 L86 15.H. 1 69.3 201 226.3 103.1 266 299.5 137.8 72 Sl.l :!6. s 1 "7 151.2 69.8 202 227.4 103.7 267 300.6 138.4 73 S2. 2 87.8 188 155. I 70.:? 203 22S. 5 104.2 268 301.7 138.9 74 :;-. s 189 I5ti.;, 70. s 201 229. 7 104.7 269 302. S 139.5 75 64 I 88.80 110 167.6 71.3 205 230.8 105. 3 270 304.0 140. 0 i 144 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. i TABLE VIII. — Allihn'a table for the determination of dextrose — Continued. Milli- grams of cop- 'per. Milli- grams of cu- prous oxid. Milli- grams of dex- trose. Milli- grams of cop- per. Milli- grams of cu- prous oxid. Milli- grams of dex- trose. Milli- grams of cop- per. Milli- grams of cu- prous oxid. Milli- grams of dex- trose. Milli- grams of cop- per. Milli- grams of cu- prous oxid. Milli- grams of dex- trose. 271 305.1 140.6 321 361.4 168.1 371 417.7 196.3 421 474.0 225.1 272 306.2 141.1 322 362. 5 168.6 372 418.8 196.8 422 475.6 225. 7 273 307.3 141.7 323 363.7 169.2 373 420.0 197.4 423 476.2 226.3 274 308.5 142.2 324 364.8 169.7 374 421.1 198.0 424 477.4 226. 9 275 309.6 142.8 325 365.9 170.3 375 422.2 198.6 425 478.5 227.5 276 310.7 143.3 326 367.0 170.9 376 423.3 199.1 426 479.6 228.0 277 311.9 143.9 327 368.2 171.4 377 424.5 199.7 427 480.7 228.6 278 313.0 144.4 328 369.3 172.0 378 425.6 200.3 428 481.9 229.2 279 314.1 145.0 329 370.4 172.5 379 426.7 200.8 429 483.0 229.8 280 315. 2 145.5 330 371.5 173.1 380 427.8 201.4 430 484.1 230. 4 281 316.4 146.1 331 372.7 173.7 381 429.0 202. 0 431 485.3 231.0 282 317.5 146.6 332 373.8 174.2 382 430. 1 202.5 432 486.4 231.6 283 318.6 147.2 333 374.9 174.8 383 431.2 203.1 433 487.5 232. 2 284 319.7 147.7 334 376.0 175.3 384 432.3 203.7 434 488.6 232.8 285 320.9 148.3 335 377.2 175.9 385 433.5 204.3 435 489.7 233.4 286 322.0 148.8 336 378.3 176.5 386 434.6 204.8 436 490.9 233.9 287 323.1 149.4 337 379.4 177.0 387 435.7 205.4 437 492.0 324.5 288 324.2 149.9 338 380.5 177.6 388 436.8 206.0 438 493.1 235.1 289 325. 4 150.5 339 381.7 178.1 389 438.0 206. 5 439 494.3 235.7 290 326.5 151.0 340 382.8 178.7 390 439.1 207.1 440 495.4 236.3 291 327.4 151.6 341 383.9 179.3 391 440. 2 207. 7 441 4%. 5 236.9 292 328.7 152.1 342 385.0 179.8 392 441.3 208.3 442 497.6 237.5 293 329. 9 152.7 343 386.2 180.4 393 442.4 208.8 443 498.8 238.1 294 331. 0 153. 2 344 387.3 180.9 394 443. 6 209. 4 444 499.9 238.7 295 332.1 153.8 345 388.4 181.5 395 444.7 210.0 445 501.0 239.3 296 333.3 154.3 346 389.6 182.1 396 445. 9 210. 6 446 502.1 239. 8 297 334.4 154.9 347 390.7 182.6 397 447.0 211.2 447 503. 2 240.4 298 335. 5 155.4 348 391.8 183.2 398 448.1 211.7 448 504.4 241.0 299 336.6 156.0 349 392.9 183.7 399 449. 2 212. 3 449 505.5 241.6 300 337.8 156.5 350 394.0 184.3 400 450.3 212.9 450 506.6 242.2 301 338.9 157.1 351 395.2 184.9 401 451.5 213.5 451 507.8 242. 8 302 340.0 157. 6 352 396.3 185.4 402 452. 6 214. 1 452 508.9 243.4 303 341.1 158.2 353 397.4 186.0 403 453.7 214.6 453 510.0 244.0 304 342.3 158.7 354 398.6 186.6 404 454.8 215.2 454 511.1 244.6 305 343.4 159.3 355 399.7 187.2 405 456.0 215.8 455 512.3 245.2 306 344.5 159.8 356 400.8 187.7 406 457.1 216.4 456 513.4 245.7 307 345.6 160.4 357 401.9 188.3 407 458.2 217.0 457 514. 5 246.3 308 346.8 160.9 358 403.1 188.9 408 459.4 217.5 458 515.6 246.9 309 347.9 161.5 359 404.2 189.4 409 460.5 218.1 459 516.8 247.5 310 349.0 162.0 360 405.3 190.0 410 461.6 218 7 460 517. 9 248.1 311 350.1 162.6 361 406.4 190.6 ' 411 462.7 219.3 461 519.0 248.7 312 351.3 163.1 362 407.6 191.1 412 463.8 219.9 462 520.1 249.3 313 352. 4 163.7 363 408.7 191.7 413 465. 0 220.4 463 521.3 249.9 314 353.5 164.2 . 364 409.8 192.3 414 466.1 221.0 315 354.6 164.8 365 410.9 192.9 415 467.2 221.6 316 355.8 165.3 366 412.1 193.4 416 468.4 222. 2 317 356.9 165.9 367 413.2 194.0 417 469.5 222.8 318 358.0 166. 4 368 414.3 194.6 418 470.6 223. 3 319 359. 1 167.0 369 415.4 195.1 419 471.8 223.9 320 360.3 167.5 370 416.6 195.7 420 472.9 224.5 TABLE IX. — Determination of maltose in beer. [According to Wein.] Milli- grams of cop- per. Milli- grams of cu- prous oxid. Milli- grams of mal- tose. Milli- grams of cop- per. Milli- grams of cu- prous oxid. Milli- grams of mal- tose. Milli- grams of cop- per. Milli- grams of cu- prous oxid. Milli- grams of mal- tose. Milli- grams of cop- per. Milli- grams of cu- prous oxid. Milli- grams of mal- tose. 31 34.9 26.1 36 40.5 30.5 41 46.2 34.8 46 51.8 39.1 32 36.0 27.0 37 41.7 31.3 42 47.3 35.7 47 52.9 40.0 33 37.2 27.9 38 42.8 32.2 4:5 48. 4 36.5 IS 54.0 40.9 34 88.8 28.7 39 43.9 88. 1 1 1 49. 5 37.4 49 55.2 41.8 35 :;•.». 1 29.6 lit 45.0 88. (.i 4:> 50. 7 88. :; 50 56.3 42.6 REFERENCE TABLES. TAKLK IX. — /h'd'riniiintioii <>f maltose in beer — Continued. 145 Milli- grams of cop- per. Milli- grams of cu- nnms oxid.. Milli- grams of mal- tose. Milli- grams of cop- per. Milli- grams of cu- prous oxid. Milli- grams of mal- tose. Milli- grams of cop- per. Milli- grams of cu- prous oxid. Milli- grams of mal- tose. Milli- grams of cop- per. Milli- grams of Cll- proua o.xid. Milli- grams of mal- tose. 51 57.4 43.5 116 130.6 100.8 181 203.8 159.2 246 277.0 217.2 52 68. 5 ii. t 117 131.7 101.7 182 204.9 160.1 247 278.1 218. 1 53 59. 7 45.2 118 132.8 102.6 183 206.0 160.9 248 279. 2 219.0 54 60.8 46.1 119 134.0 103.5 184 207. 1 161.8 249 280.3 219. 9 55 61.9 47.0 120 135.1 104.4 185 208.3 162.7 250 281.5 220.8 56 63.0 47.8 121 136.2 105.3 186 209.4 163.6 251 282.6 221.7 57 64.2 48.7 122 137.4 106.2 187 210.5 164.5 252 283.7 222. 6 58 65.3 49.6 123 138. 5 107.1 188 211.7 165.4 253 284.8 223.5 59 66.4 50.4 124 139.6 108.0 189 212.8 166.3 254 286. 0 224. 4 60 67.6 51.3 125 140.7 108.9 190 213.9 167.2 255 287.1 226. :; 61 68.7 52. 2 126 141.9 109.8 191 215.0 168.1 256 288.2 262.2 62 69.8 53.1 127 j 143.0 110.7 192 2 If.. 2 169.0 257 289.3 227.1 63 70.9 53.9 128 144.1 111.6 193 217.3 169.8 258 290.5 228.0 64 72.1 54.8 129 145. 2 112.5 194 218.4 170.7 259 291.6 228. 9 65 73.2 5.'). 7 130 146.4 113.4 195 219.5 171.6 260 292.7 229.8 66 74.3 5T,. (I 131 147.5 114.3 196 220.7 172.5 261 293.8 230.7 67 76.4 57.4 132 148.6 115. 2 197 221.8 173.4 262 295.0 231.6 68 76.6 as. ;{ 133 149.7 116.1 198 222.9 174.3 263 296.1 2:52. f> 69 77.7 .")'.». 2 134 1.50.9 117.0 199 224.0 175. 2 264 297.2 233.4 70 78.8 60.1 135 152.0 117.9 200 225. 2 176.1 265 298.3 234.3 71 79.9 61.0 136 153.1 118.8 201 226.3 177.0 266 299.5 235.2 72 S1.1 f.i.s 137 164.2 119.7 202 227.4 177.9 267 300.6 2:?f,. l 7:; 82.2 f.2. 7 138 l.V,. 1 120.6 203 228.5 17S.7 268 301.7 237.0 71 88. :'. 63.6 139 166.5 121.5 204 229.7 179.6 269 302.8 237. '.) 75 84.4 M. 5 140 157.6 122.4 205 230.8 180.5 270 304.0 238.8 76 85.6 65.4 141 158.7 123.3 206 231.9 181.4 271 305.1 239.7 77 Mi. 7 66.2 142 169. 9 124.2 207 233.0 182.3 272 306.2 240.6 78 87.8 67.1 143 161.0 125.1 208 234.2 183.2 273 307.3 241.5 79 88.9 68.0 144 162.1 126.0 209 235.3 184.1 274 308.5 242.4 80 90.1 68.9 145 163.2 126. 9 210 236.4 185.0 275 309.6 243. 3 81 91.2 69.7 146 164.4 127.8 211 237.6 185.9 276 310.7 244.2 82 92.3 70.6 147 165.5 128.7 212 238.7 186.8 111 311.9 245.1 93.4 71.5 148 166.6 129.6 218 239. 8 187.7 278 313.0 246.0 84 94.6 72.4 149 167.7 130.5 214 240. 9 188.6 279 314.1 246.9 85 '.>:>. 7 73.2 150 168.9 131.4 215 242. 1 189.5 280 315.2 247.8 sti 96.8 74.1 151 170.0 132.3 216 243. 2 190.4 281 316.4 248.7 87 97.9 78.0 l.V-' 171.1 133.2 217 244.8 191.2 282 317.5 24'.). f, 88 99.1 75. 9 15:; 172.:; ' 134.1 218 246.4 192.1 283 318.6 250.4 89 100.2 7(i. 8 154 173.4 135.0 219 246.6 193.0 284 319.7 261.8 90 101.3 77.7 155 174,6 135.9 220 2 47. 7 193.9 285 320.9 252.2 91 102.4 78.6 156 175.6 136.8 221 248.7 194.8 286 322.0 253.1 92 103.6 79.5 157 176.8 137.7 222 249. 9 195.7 287 323.1 254.0 93 104.7 80.3 158 177.9 L38.6 223 251.0 196.6 288 324. 2 264.9 94 106.8 81.2 159 179.0 139.5 224 252. 4 197. 5 . 289 325. 4 255.8 95 107.0 82, 1 160 180.1 140.4 225 253. 3 198.4 290 326.5 256.6 96 108.1 s:;. i) 161 181.8 141.3 226 254.4 199.3 291 327.4 257. 5 97 109.2 83.9 162 182.4 1 12. 2 227 255.6 200.2 292 328.7 258.4 98 110.3 84.8 hi:; is3.5 143. 1 228 266.7 201.1 293 329.9 259. 3 99 111. 5 s:>. 7 nil isi.i; 144.0 229 257. s 202. 0 2'.» 1 831.0 260. 2 100 i]2.f, -sc..r. it;:, 186.8 lll.'.t 230 258.9 202. 9 295 882. 1 261.) 101 113.7 s7. r, 166 186.9 115. s 231 260.1 203.8 296 333.2 2f,2. 0 102 114.8 ss. 4 167 188.0 146.7 232 261.2 201.7 297 334.4 2(12. S 103 116.0 s'.l. 2 168 189.1 147.6 233 262.3 205. 6 298 :;:;:,.:, 2(53. 7 104 117.1 '.»(). 1 169 190. 3 1 is. :> 234 2f.3. 1 206.5 2W :;:!ii.f. 264.6 105 118.2 91.0 170 191.4 I !'.». 1 235 264.6 207.4 300 :»7. s 2(55. ft 106 119.3 91.9 171 192. ft 150.3 23< i 265.7 208.3 107 120.5 92. s 172 193. 6 151.2 2:;7 266.8 20'.l. 1 108 121.6 '.»:;. 7 17:; 194,8 162.0 238 268.0 210.0 109 122.7 94.6 171 196.9 152. 9 239 2f.'.». 1 210. 9 110 123. 8 !i5. 5 17:, 197.0 153.8 240 270. 2 211.8 111 128.0 96.4 176 108.1 164,7 211 271.3 212.7 112 126. 1 97.3 177 199.8 L65.6 212 272. 5 213. 6 113 127.2 98. 1 17s 200.4 243 273.6 214.6 114 128.3 99.0 17(.» 201.5 167. 1 244 274.7 215 1 118 129.6 '.t'.i. '.» iso L-irj.i; [68.3 246 27.",. s 216.3 KJC4S No. r,5— 02- 10 146 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. TABLE X. — Per cent of fat and solids not fat in milk. [According to Babcock.] Per cent of fat. Lactometer readings at 15.6° C. Per cent of fat. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 1 0.0 6.50 6.75 7.00 7.25 7.50 7.75 8.00 8.25 8.50 8.75 9.00 0.0 0.1 6.52 6.77 7.02 1 7.27 7.52 7.77 8.02 8.27 8.52' 8.77 9.02 0.1 0.2 6.51 6.79 7.04 7.29 7.54 7.79 8.04 8.29 8.54 8.79 9.04 0.2 0.3 6. 56 6. 81 7. 06 7. 31 7. 56 7.81 8.06 8. 31 8. 56 8.81 9.06 0.3 0.4 6.58 6.83 7.08 7.33 7.58 7.83 8.08 8.33 8.58 8.83 9.08 0.4 0.5 6. 60 6.85 7.10 7.35 7.60 7.85 8.10 3.35 8.60 8.85 9.10 0.5 O.G 6.62 6.87 7.12 7.37 7.62 7.87 8.12 8.37 8.62 8.87 9.12 0.6 0.7 6.64 6.89 7.14 7.39 7.64 ".89 8.14 8.39 8.64 8.89 9.14 0.7 0.8 6.66 6.91 7.16 7.41 7.66 7.91 8.16 8.41 8.66 8.91 9.16 0.8 0.9 6.68 6.93 7.18 7.43 7.68 ".93 8.18 8.43 8.68 8.93 9.18 0.9 1.0 6.70 6.95 7.20 7.45 7.70 ".95 8.20 8.45 8.70 8.95 9.20 1.0 1.1 6.72 6.97 7.22 7.47 7.72 ".97 8.22 8.47 8.72 8.97 9.22 1.1 .2 6.74 6.99 7.26 7.49 7.74 7.99 8.24 8.49 8.74 8.99 9.24 .2 .3 6.76 7.01 7.24 7.51 7.76 8.01 8.26 8.51 8.76 9.01 9.26 .3 .4 6.78 7.03 7.28 7.53 7.78 8.03 8.28 8.53 8.78 9.03 9.28 .4 .5 6.80 7.05 7.30 7.55 j 7.80 8.05 8.30 8.55 8.80 9.05 9.30 .5 .6 6.82 7.07 7.32 7.57 7.82 8.07 8.32 8.57 8.82 9.07 9.32 .6 .7 6.84 7.09 7.34 7.59 7.84 8.09 8.34 8.59 8.84 9.09 9.34 .7 1.8 6.86 7.11 7.36 : 7.61 7.86 8.11 8.36 8.61 8.86 9.11 9.37 .8 1.9 6.88 7. 13 7. 38 7.63 1 7.88 8.13 8.38 8.63 8.88 9.13 9.39 .9 2.0 6.90 7. 15 7. 40 7.65 7.90 8.15 8.40 8.66 8.91 9.16 9.41 2.0 2.1 6.92 7. 17 7. 42 7.67 7.92 8.17 8.42 8.68 8.93 9.18 9.43 2.1 2.2 6.94 7.19 7.44 7. 69 7. 94 8.19 8.44 8.70 8.95 9.20 9.45 2.2 2.3 6.96 7.21 7.46 7. 71 7. 96 8.21 8. 46 8. 72 8.97 9.22 9.47 2.3 2.4 6.98 7.23 7.48 7.'73 7. 98 8.23 8.48 8.74 8.99 9.24 9.49 2.4 2.5 7.00 7.25 7.50 7. 75 8. 00 8.25 8.50 8.76 9.01 9.26 9.51 2.5 2.6 7.02 7.27 7.52 7.77 8.02 8.27 8.52 8.78 9.03 9.28 9.53 2.6 2.7 7.04 7.29 7.54 7.79 8.04 8.29 8.54 8.80 9.05 9.30 9.55 2.7 2.8 7.06 7.31 7.56 7.81 8.06 8.31 8.57 8.82 9.07 9.32 9.57 2.8 2.9 7.08 7.33 7.58 7. 83 8. 08 8.33 8.59 8.84 9.09 9.34 9.59 2.9 3.0 7.10 7. 35 7.60 7. 85 8.36 8.61 8.10 8.86 9.11 9.36 9.61 '3.0 3.1 7.12 7.37 7.62 7.87 8.38 8.63 8.13 8.88 9.13 9.38 9.64 3.1 3.2 7.14 7.39 7.64 7.89 8.40 8.65 8.15 8.90 9.15 9.41 9.66 3.2 3.3 7.16 7.41 7.66 7.92 8.42 8.67 8.17 8.92 9.18 9.43 9.68 3.3 3.4 7.18 7.43 7.69 7.91 8.44 8.69 8.19 8.94 9.20 9.45 9.70 3.4 3.5 7.20 7.45 7.7] 7.9C) 8.46 8.71 8.21 8.96 9.22 9.47 9.72 3.5 3.6 7.22 7.48 7.73 7.98 8.48 8.73 . 8. 23 •8.98 9.24 9.49 9.74 3.6 3.7 7.24 7.50 7.75 8.00 8.50 8.75 8.25 9.00 9.26 9.51 9.76 3.7 3.8 7.26 7.52 7.77 8. 02 8. 52 8.77 8.27 9.02 9.28 9.53 9.78 3.8 3.9 7.28 7.54 7.79 8.04 ! 8.54 8.79 8.29 9.04 9.30 9.55 9.80 3.9 4.0 7.30 7.56 7.81 8.06 , 8.56 8.81 8.31 9.06 9.32 9.57 9.83 4.0 4.1 7.32 7.58 7.83 8. 08 8. 58 8.83 8. 33 9. 08 9.34 9.59 9.85 4.1 4.2 7.34 7.60 7.85 8.10 8.60 8.85 8.35 9.11 9.36 9.62 9.87 4.2 4.3 7.36 7.62 7.87 8.12 8.62 8.88 S. 87 9. 13 9.38 9.64 9.89 4.3 4.4 7.38 7.64 7. 89 8. 14 8.64 8.90 S. : 9 9. 15 9.40 9.66 9.91 | 4.4 4.5 7.40 7.66 1 7.91 8.16 8.66 8.92 8. 41 9. 17 9.42 9.68 9.93 4.5 4.6 7.43 7.68 ! 7.93 8.18 8.68 8.94 8.43 9.19 9.44 9.70 9.95 4.6 4.7 7.45 7.70 7.95 8.20 8.70 8.96 8. 45 9. 21 9.46 9.72 9.97 4.7 4.8 7.47 7.72 7.97 8.22 8.72 8.98 8. 47 9. 23 9.48 9.74 9. 99 4. 8 4.9 7.49 ! 7.74 7.99 8.24 8.74 9.00 ! 8.49 9.25 9.50 9.76 10. 01 4. 9 5.0 7. 51 7. 76 8.01 8.26 8.76 9.02 8.51 ! 9.27 9.52 9.78 10.03 5.0 5.1 7.53 7. 78 8.03 8.28 8.79 9.04 8.53 9.29 9.54 9.80 10.05 5.1 5.2 7.55 7.80 8.05 8.30 8.81 9.06 8.55 9.31 9.56 9.82 10.07 5.2 5.3 7.57 7.82 8.07 8.32 8.83 9.08 8. 57 9. 33 9.58 9.84 10. 09 5. 3 5.4 7.59 7.84 8.09 8.34 8.85 9.10 8.60 9.36 9.61 9.86 10.11 5.4 5.5 7.61 7.86 8.11 8.36 8.87 9.12 8.62 9.38 9.63 9.88 10.13 5.5 5.6 7.63 7.88 8.13 8.39 8.89 9.15 8.64 9.40 9.65 9.90 10.15 5.6 5.7 7.65 7.90 8.15 8.41 8.91 9.17 8.66 9.42 9.67 9.92 10.17 5.7 5.8 7.67 7.92 8.17 8.43 8.94 9.19 8.68 9.44 9.69 9.94 10.19 5.8 5.9 7.69 7.94 8.20 8.45 8.96 9.21 •8.70 9.46 9.71 9.96 10.22 5.9 6.0 7.71 ' 7.% 8.22 8.47 8.98 9.23 8.72 9.48 | 9.73 9.98 10. 24 6. 0 KKFERENCE TABLES. 147 TABLE XI. — Atomic ?/r«////.s-. Name. Svm- bol. Atomic weight. Name. Sym- bol. Atomic weight. H 1. 0=16. H=l. O=16. Aluminum Antimony Al.... St 26.9 119.5 74. 45 13(5.4 206.5 10.9 79. 34 111.55 131.9 39.8 11.9 138.0 35. 18 51.7 93^0 164^7 18.9 155.8 69.5 71.9 9.0 195.7 1.000 113.1 125.89 191.7 55.5 137.6 205.86 6.97 24.1 54.6 198.50 95.3 27.1 120.4 75.0 137. 40 208.1 11.0 79. 95 112.4 132.9 40.1 12.0 139.0 35.45 52.1 59.00 93.7 63.6 166.0 19.05 157. 0 70.0 72.5 9.1 197. 2 1.008 114.0 126.85 193.1 55.9 138.6 206.92 7.03 24.8 55.0 200.0 96.0 Neodvmium 142.5 58.25 13.93 189.6 15.88 106.2 30.75 193.4 139! 4 102.2 84.75 100.9 149.2 43.8 78.6 28.2 107. 11 22.88 86.95 31.83 181.5 126.5 158.8 202.61 230.8 169.4 118.1 47.8 182.5 237.8 51.0 17]. 9 88.3 64.9 89.7 143.6 58.70 14.04 191.0 16.000 107.0 31.0 194.9 39.1 140.5 103.0 85.4 101.7 150.3 44.1 79.2 28.4 107.92 23.05 87.60 32.07 182.8 127. 52 160.00 204.15 232.6 170.7 119.0 48.15 184.00 239.6 51.4 173.2 89.0 65.4 90.4 Nickel Ni Arsenic As Nitrogen \ Barium Ba Os Bismuth Bi . . . . Oxvgen o Bor< >ii B I'd Bromine Br... Phosphorus p Cadmium . . Cd.... Platinum Pt Caesium Cs ... Calcium Ca . . . . Praseodymium c Rh Cerium Ce... Rubidium Rb Chlorine Chromium Cobalt Cl .... Cr.... Co... Ruthenium Samarium Scandium Ru ... Sm ... Sc . . . . Se Cnlumbium Copper Erbium Cb.... Cu.... Er.... Selenium. . Silicon Si Silver Sodium Strontium Ag.... Na.... Sr Fluorine F Gadolinium Gallium Ga Sulphur g Germanium 1... Glucinum Ge.... GJ.... Au Tantalum Tellurium Ta.... Te Gold Terbium Thallium Tb.... Tl 1 1 yd r< >gen H Indium In Th Iodine I Thulium Tu Iridium Ir Tin Sn Iron Fe . . . . Titanium Ti Lanthanum. La . Tungsten W Lead Pb u Lithium Magnesium Manganese Li .... Mg... Mn ... Vanadium v Ytterbium Yttrium Zinc . . . Yb.... Yt.... Zn Mercury • Molybdenum Hg ... Mo ... Zirconium Zr .... •Clarke, Jour. Am. Chern. Soc., 1901, 23, 90. APPENDIX. As stated in the introduction, the methods given in the body of this report were submitted to about 250 chemists for criticism before they were reported to the asso- ciation. The replies received were referred to the various authors and later were considered by them jointly at a meeting held on November 13, 14, 1901. All suggestions that those present approved of from their own experience .were incor- porated in the methods reported to the association and are published in this bulletin. In this appendix are given extracts 1'roiu replies containing other suggestions, which, though not adopted, were thought to be valuable and worthy of consideration at the hands of other analysts. At the beginning of each extract are indicated the page and the chapter subdivision of this bulletin containing the matter to which the criticism refers. The comments are by the referee. MEAT AM) MKAT PRODUCTS. Page 7, 1. — Practical men will sometimes say that this or that beef is cotton-seed-fed or slop-fed, judging simply from the appearance of the fat. No doubt such fats do give different factors which it might be well to take into account. — 7>. M. 7V///W///. Page 10, 4, 5, and 7 (a). — Forthe determination of water, ash, fat, and total nitro- gen I have dried a weighed amount (50 grams) of finely chopped meat on a tared, flat, porcelain or nickel dish till the weight is approximately constant after it has stood in the atmosphere of the room over night. This is then immediately tinely powdered and tightly stoppered, and is used for the above determinations. — E. E. Smith, Page 10, 6. — Two grams of the dried sample seems an unnecessarily large quantity. I have used 0.5 to 1.0 gram. 1 think it would be well to specify "passed through a 100 (or 80) mesh sieve."— E. E. Smith. Page 12, 7, (f ). — It is quite common to determine meat bases directly by the bromin method without previous determinations of proteoses, peptones, and gelatin. How would the results thus obtained compare with those obtained according to (f)? Is the direct estimation of meat bases from the amount of nitrogenous matter not pre- cipitated by bromin incorrect? — A. P. Bryant. CoHiiin-Ht by Mr. Bigelow. — Results by Mr. Trescot in this laboratory show a mate- rial error in the method suggested by Mr. Bryant, owing t<> the decomposition of meat bases with the evolution of nitrogen. Page 16, 13. — I have succeeded best in extracting coloring matter from sausage^ by maceration with acidulated alcohol, using hydrochloric acid. — A. 8. Mitchell. EDIBLE OILS AND FATS. Page 20, 2. — In preference to the three methods given, 1 consider the Sprengel-tube method by far the most accurate, as well as the most rapid, process for determining the specific gravity at the boiling point. This is particularly the case when a large number of samples have to be examined together. I may add that I consider accurate determinations of specific gravity especially 149 150 PROVISIONAL METHODS FOE ANALYSIS OF FOODS. valuable when taken in conjunction with some other measurement (volatile acid, iodin, absorption, etc.)- A fairly constant ratio may often be observed between the specific gravity and other measurements for a particular oil. Addition of an adul- terant may upset this relationship without, however, bringing the specific gravity (or other measurement) outside the limits for the pure oil. — Edgar B. Kenrick. Page 22, 2, (b), (2). — Why not use Westphal balance to determine specific gravity at temperature of boiling water? — A. G. Woodman. Page 22, 3. — I think it is time that a vigorous protest be made against the practice, now becoming quite common, of reporting refractive indices by purely arbitrary numbers. One would think that the confusion resulting from the use of Twaddell, Baume", etc. , degrees of specific gravity should be sufficient warning. The omission of any statement as to the optical relation between the readings of the Zeiss instrument and the refractive indices leaves the reader in doubt as to whether the table given is of any use beyond the individual instrument for which it was constructed. The writer of a recent text-book on physical measurements gives at the end of the book a table for the conversion of the readings of the Pulfrich refractometer into refractive indices. No warning is given to the reader that the table will not apply to any Pulfrich refractometer. The table, in fact, is quite useless for the instrument now in use in my laboratory. The index of refraction in the Pulfrich instrument is the square root of the difference between the square of the refractive index of the glass prism and the square of the* sine of the angle measured. Since the refractive index of the prism in any particular instrument is not the same as that of the one for which the table in the book is made, it is obvious that the said table can not be used with my instrument. After an experience of twelve years with two forms of the Pulfrich refractometer, I am able to say that this instrument leaves nothing to be desired in point of accuracy and ease of operation. — Edgar B. Kenrick. Page 25, 4. — In weighing the fat for determination of iqdin absorption I use Wes- son's small, flat-bottomed glass cylinders and a narrow-mouthed bottle. (See our report for 1896, p. 23. ) Would it not be well to make the instruction a little more elastic, so as to cover any form of glassware found efficient? — A. L. Winton. Referring to the "wide-mouth bottle," I should prefer small glass stopper on account of greater danger of loss of iodin from large one. — A. G. Woodman. Page 26, 5, (a). — It has always been customary in the laboratory at Munich, Bavaria, under Professor Hilger, to keep the solutions of iodin and mercuric chlorid separate. They were mixed in equal proportions forty-eight hours before use. — Emil ScMichting. Page 26, 5, (b) and (c). — Instead of about 5 grams of the melted fat, I think it better to use from 1 to 2 grams. Instead of a reflux condenser, I prefer a small funnel placed in mouth of flask. This is perfectly satisfactory and more con- venient.— A. G. Woodman. Page 29, 11. — The method of using 5 grams of fat is satisfactory for most analytical work, but that I may be able to present a sample of the adulterant found as evidence in court, in the case of adulterated linseed oils, it has been my practice to use 10 grams, following the method of Morawski and Demski, page 172 of Benedikt and Lewkowitzch (Oils, Fats, and Waxes). By this method the removal of the alcohol used in saponification is avoided, as is also to a great extent the solubility of the alkaline soap solution in ether. Ten grams of fat are saponified in a flask with 5 grams of caustic potash dissolved APPENDIX. 151 in the leapt amount of water and 50 cc of stronger alcohol. The mixture is boiled for half an hour with inverted condenser. (I have found saponifieation by this method insufficient in the case of waxes, notably beeswax.) After saponification 50 ccofhot water are added, the, mixture is cooled, and shaken out with petroleum ether. Page 30, 12. — Commenting upon this method, I will state that while Wiley's method is undoubtedly the most accurate for determination of the melting point, the capillary- tube method is so much more convenient that most of the chemists in this section use it in their commercial work. I would suggest that that method be reinstated as an alternate method. — A. /ST. Mitchell. Page 32, 14. — The directions for the Maumene figure are doubtless designed espe- cially for olive oil; but inasmuch as cotton-seed, sesame, or poppy seed and the like might be included among edible oils, would it not be well to consider whether " strongest" sulphuric acid can be added to the latter oils without such frothing and evolution of S02 as would vitiate the results? Some experiments on the Maumene test have recently been made in this laboratory a. The details are now being prepared for publication. — H. C. Sherman. Comment by Mr. Tolman. — This suggestion regarding the method for determining the Maumene figure is very appropriate and it will be necessary to modify the method when working with such oils as are mentioned above. Sherman a uses an acid which will give a rise of temperature with water of 33°-34° C., and calculates the "specific temperature reaction" as ;,'iven in the methods for oil analysis. But he finds that slightly lower results are obtained by this method. Each analyst should determine the constants for the conditions under which he is working. Page 33, 17. — I should prefer to use the fatty acids for the Bechi test rather than the oil or fat itself. — A. G. Woodman. DAIRY PRODUCTS. Page 35, 2. — The dish used should be platinum or light porcelain. I should bar the use of either aluminum or tin. They are too easily subject to corrosion and change of weight. A small rod, about 1 inch by 3 or 4 millimeters, should be weighed with the dish, and the milk and sand should be stirred up when milk is added. This will greatly facilitate drying and no crust will form on top of the sand. In this manner more milk can be advantageously used, and I should advise increasing the amount to an optional 5 or even 10 cc. Anyone using the rod once will never after do without it. — Charles L. Parson*. Page 36, 6. — From the expression, "if the milk contains one or more parts per 10,000 of formaldehyde," one would gather that the test will detect any amount of formaldehyde greater than one part per 10,000, whereas I believe that if the amount of formaldehyde be increased above a certain point the test will no longer show it. — .1. d'. ]\'<><> Jour. Am. Chem. Soc., 1898, 20,110. APPENDIX. 153 Page 55, 3. — I would suggest temperature of water bath, say about 100° instead of 110° C. A great many laboratories! have only water baths, and the temperature obtainable is only 100° C.— -/. A. Le Clerc. Comment. />>/ Mr. ]\'inlnn. — Temperature of 110°, although in some ways not so con- venient as 100°, facilitates the removal of the volatile oils. 1 'age 56, 10. — Most published methods involve the assumption that oil of cloves exerts no vapor pressure at ordinary temperatures. This is very far from being the ease. In the process described on page 2, a mixture of ether and oil of cloves will lose both ether and oil of cloves when allowed to "evaporate at room temperature." A second loss will take place in standing eighteen hours over sulphuric acid, the sulphuric acid continually absorbing the vapor of the oil as it is given off. If cloves are finely powdered and exposed to the air in a thin layer, it will be found that after the lapse of a week or two the loss in weight which has taken place will be approximately equal to the amount of volatile oil originally present. The final weight, or rather the weight after the oil has evaporated, will vary slightly with the pressure of water vapor in the atmosphere. The fact that commercial ground cloves often contain very little volatile oil may sometimes be due to the fact that the cloves have been long ground, the oil having escaped by evaporation. The correct method indicated would seem to be: (1) Allow one of the volatile constituents to become in equilibrium with a limited atmosphere kept continually saturated with this constituent (e. g., water) at a given ten i]>erature. (2) Allow the other volatile constituent (oil) to evaporate completely into an unlimited atmosphere free from this constituent. (3) Restore the original conditions in (1). The difference in weight between (1) and (3) wrill give the weight of the second constituent. (All the oil and water may be driven off by a few hours' heating in a \vater oven.) I have used various modifications of the above principle, but have so far had no opportunity of checking their absolute accuracy, as all published methods seem to me wron<; in principle for the reason already given. —E. B. Kenrick. Page 56, 10. — A student in this laboratory, Mr. L. L. Watters, last year made some experiments in regard to the determination of oil of sage by a method practically the same as this, except that very light petroleum ether was used for extraction. He found that it was difficult to drive off all of the ether without some of the oil, or to tell when all the solvent was driven off. Also sage oil left a residue, small, but rat her variable, when evaporated, ami brought to constant weight at 100° C. He thought the amount of residue thus left was influenced by the other constituents of the ether extract. A partial correction was obtained by adding to an aliquot part of the ether solution, before evaporation, a known weight of sage oil and carrying this through the same process as a blank. Possibly it might be worth wrhile to try some- thing of this sort with other volatile oils.—//. C. Sherman. Com UK' nt l>i/ M,-. ]Vinton. — Our standards are based on ether extraction. The method, we know, is not perfect, but we should go slow in making changes. The points named are worthy of further study. Page •")(;, 10. — Could not petroleum ether or gasoline be used alternatively here or wherever extraction with absolute ether is recommended? The latter is better on account of the dilliculty of keeping the ether perfectly anhydrous during the extrac- tion. -A. (!. }\'(liixiii. Comment />>/ Mr. Wmton.— Petroleum ether has certain advantages over ether, but among the disadvantages in this instance is the fact that our standards of composition are based on the other method. 154 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. Page 56, 10. — Under determination of volatile and nonvolatile ether extracts I think he consumes too much time. He extracts with a continuous apparatus for twenty hours. — /. A. Wesener. Comment by Mr. Winton. — The method for volatile and nonvolatile ether extract takes time, but I have found no satisfactory short cuts. Furthermore, our proposed standards are based on this method. Page 56, 11. — Alcohol extracts from pepper a large amount (10 to 12 per cent) of matter which is easily volatile from its alcoholic solution, but is not volatile at the same temperature by dry heating. (See Bui. 10, Inland Eevenue Laboratory, p, 18. ) — A. McGill Comment by Mr. Winton. — A matter worthy of future study. Page 57, 12. — The method we are using and one we much prefer to the copper- reducing method for sugars is to conduct the determination similarly to the copper- plating method until the copper suboxid has been dissolved in nitric acid. Then proceed as follows: Add sulphuric acid to displace the excess of nitric acid and boil until all fumes of nitric dioxid have disappeared. Then neutralize with sodium car- bonate. Redissolve the precipitated copper in acetic acid, boil to expel excess of that acid, cool, and add enough potassium iodid to change all of the copper to cuprous iodid, with the liberation of free iodin. The free iodin thus liberated is then titrated with deci-normal ammonium thiosulphate, using starch as indicator. This method in our laboratory is both rapid and accurate. — /. A. Wesener. Comment by Mr. Winton.^The association gives choice of several methods for determining of reduced copper, any of which may be employed. Personally,. I prefer weighing either the CuO or Cu2O in a Gooch crucible. Page 57, 12. — In following Allihn's method, you direct that the solution, after addition of reducing solution, be heated merely to boiling, whereas in the A. 0. A. C. version the solution is boiled two minutes. — W. D. Bigelow. Comment by Mr. Winton. — The table used in connection with the Allihn method is based on Allihn's experiments with different quantities of pure dextrose, heating in each case until boiling begins again. So long as we use Allihn's table, we should follow his instructions. The writer, in a long series of experiments11 with both pure starch and dextrose, found that the original Allihn method gave accurate results, whereas longer boiling brought the results too high. The German food analysts use the original Allihn method. Page 57, 12. — We have found it better to make the copper solution very slightly acid. We include 1 cc of strong sulphuric acid in the 500 cc of copper sulphate solution. — A. G. Woodman. Comment by Mr. Winton. — A subject for study by the association. Page 58, 14. — Several inquiries have been received regarding the details of the method prescribed for the determination of crude fiber. Paper always gives a clear filtrate and nearly filters rapidly, whereas linen does not always retain the fine material and Gooch crucibles sometimes clog, rendering filtration impossible. A possible disadvantage of a weighed paper is that it may lose weight on treatment with soda, but this loss can be determined by blank experiment and a correction introduced. Of course a Gooch crucible is more convenient, provided it does not clog, but to make its use obligatory renders the method impossible for many sam- ples.— A. L. Winton. Page 58, 14. — In the determination of crude fiber, the centrifuge will be found a »Conn. Expt. Sta. Kept., 1897, p. 128; Jour. Anal. Chem., 1888, p. 129. APPENDIX. 155 great help; since filtration after use of alkali is almost impossible, and always most tedious.— A. Mr (,'!//. < 'oininnit !>// Mr. }\'iitton. — Use of paper obviates the slow filtration. Page 58, 14. — The only exception I take to the method of analysis as outlined is the method of estimating crude fiber. The official method is always tedious, and usually impossible with spices, owing to clogging of Gooch filter. The method as given is liable to be inaccurate, owing to difficulty of transferring fiber from paper, possibility of removing paper fiber, and the assumption that the weight of filter pa PIT after washing with water, alcohol, and ether, and drying at 100 C.° is the same as before treatment. A method I have used with satisfaction consists in filtering through linen after acid, and again after alkali treatment, then transferring to Gooch crucible and proceeding as in official method. — E. N. Eaton. Comment. — The method I recommend is that of the A. O. A. C., except that the fiber is weighed on a paper filter instead of the Gooch crucible. I can fully agree with Eaton that the "official method is always tedious and usually impossible with spices, owing to the clogging of Gooch filter/' but I prefer a paper, both for the acid and alkali filtration. There is little danger of fiber being detached from the paper after the acid filtration. Page 59, 16. — I think the Jena flasks used in determining nitrogen of nonvolatile ether extract should be described more exactly, whether round or flat-bottomed, length of neck, etc. Would it not be satisfactory to make extraction in the ordinary flask and transfer with water or ether? The ilask you prescribe could not be used with the Knoor extraction apparatus. — W. 1). Bin-. Comment by Mr. Winton. — I prefer a flat-bottomed Jena flask, 15 centimeters high, but other shapes and sizes may be used without affecting the result. The extract, after drying, is not easily removed with ether; hence it is strongly advised to digest for nitrogon in the extraction flask, transferring to a larger flask for distillation. The kind of apparatus used is not important, provided the extraction and digestion are complete, and mechanical loss is avoided. FLAVORING EXTRACTS. Page 70, 4. — I would suggest the following method for the estimation of vanillin:* Two cubic centimeters of the vanilla extract, is measured into a test tube and sufficient freshly precipitated lead hydroxid added to completely decolorize. The mixture is washed onto a filter and the filtrate and washings collected in a Nessler tube. Bro- min water is then added, after which enough of a freshly prepared 10 per cent solu- tion of ferrous sulphate is added to get the maximum bluish-green color that will be produced if vanillin is present. A standard solution is prepared by dissolving, say 50 mm of pure vanillin in 100 cc of water. A series of standards is then made, taking for instance £, 1, 2, 2$, 3, etc., cc of the vanillin solution in Nessler tubes, each being treated with 2 or 3 drops of Bromin water, and with ferrous sulphate solution, and made up to the 50-cc mark. The lead hydroxid is prepared by dissolving 200 grams of lead acetate in 850 cc of water. The solution is filtered and a strong solution of potassium hydroxid is added in excess, and the precipitate is washed thoroughly several times by decantation.b — A. E. Leach. FERMENTED AND DISTILLED LIQUORS. Page 83, 6. — When a liquor is titrated and the indicator does not give the color reaction distinctly on account of the color of the liquor after that point where the red goes to violet, the end reaction is gotten by dipping a capillary tube into the •Ztschr. anal. Cheni., 189-1, tf:$, urj. bZtschr. anal. Cheni., 1894, 38, 241>; -Mass. Hoard of Ili-.-ilih Jlt-pt. tor js-i-.i. r,-.".i. 156 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. liquid after every other cubic centimeter and putting the point of it upon a piece of litmus paper. After the absorption of the liquor from the tube the center of the blot will show the alkaline blue on red litmus paper before a drop will. This method was brought before the local section of the American Chemical Society some years ago by Dr. S. Waldbott.— B. M. Pilhashy. Page 84, 10. — Allow me to call attention to a point that is often overlooked in the examination of fermented and distilled liquors. The determination of glucose in wines, etc., is often based on the examination of the sample for dextrine. This in itself is all right except that very little commercial glucose is used in any fermented liquor except beer. The product that is used is grape sugar, which has been so highly converted that it will not give more than a qualitative test for dextrine. The only way to determine the presence of grape sugar is by double polarization before and after inversion. Nor is this positive proof of adulteration since, in some cases, invert sugar is used besides grape sugar, and the amounts are so well balanced that the polarization due to these two products is 0, In cases of this kind the addition of the foreign bodies can only be determined indirectly. The cane sugar is deter- mined by reduction before and after inversion, the difference between the two results being calculated to cane sugar. The direct reduction is then due to the mix- ture of the grape and invert sugars. A mixture of about one part of grape sugar to to 2£ parts of invert sugar will give a direct polarization, and a polarization after inversion of 0. In some cases I have found that direct polarization was due to the cane sugar added. This is only the case where the fermentation was complete and all the sugar of the grape turned into alcohol. The point that I want to bring out is that a certain relation exists between the amounts of sugars found by polarization before and after conversion, and the amounts of reducing sugars found by the reduction method before and after conversion, and that the absence of this relation is always proof of adulteration due to the addition of grape or invert sugar or both. — Edward Gudeman, BAKING POWDER AND BAKING -POWDER CHEMICALS. Page 98, 1. — Regarding the determination of carbon dioxid, I will say that I have used for factory control work a method which requires for its execution a slight modification of the Kjeldahl nitrogen apparatus, receiving the distillate in a solution of sodium hydroxid whose titre of free alkali is known; afterwards titrating with standard acid, using phenacetolin as the indicator. I am satisfied that with the cooperation of the association this method could be made as good for carbon dioxid as the Kjeldahl is for nitrogen. Figure 7 illustrates the apparatus used by myself for the estimation of carbon dioxid in low-grade phosphate rock, such as is used for fillers in the manufacture of com- mercial fertilizers. The flask C is an ordinary globe chemical flask having a capacity of 1,000 cc, fitted with a funnel tube having a stopcock at B. The flask E is an absorption flask having two bulbs, as shown. It should have a capacity of about 200 cc. The condenser D is a Liebig condenser of brass, with inner tube of block tin, as used in the Kjeldahl nitro- gen process. This tin tube is connected with the bulb tube of flask C by a bitof rub- ber tubing and terminates in a glass tube which is fitted by a rubber stopper to flask E. The determination is made as follows: Place 500 cc of freshly boiled distilled water in flask C; allow it to cool, and, if convenient, reduce its temperature to 20° or lower; then introduce into flask C about 1 gram of the substance to be estimated. Place in funnel tube a quantity of normal sulphuric acid considerably in excess of that required to decompose the substance. Place in the flask E 50 cc of normal or double normal sodium or potassium hydroxid solution. The exact content of hydroxid in this solution must be determined by titrating with decinormal sulphuric acid and phenacetolin previous to using it — in a separate, portion, of course. APPENDIX. 157 The apparatus is then connected, as shown in the illustration, with the glass tube dipping in the liquid in flask E. The stopcock B is then partly opened, and the acid is allowed to flow in at such a rate that the bubbles pass through E about one per second. Slowly increase the heat to boiling and distill about 50 cc. After the distillation, titrate the liquid in E with decinormal sulphuric acid and phenacetolin, or, better, make it up to a definite quantity and take an aliquot part for titration, stopping at the first appearance of the pink. The difference between the amount of hydroxid shown by this last titration and that known to have been con- tained in it previous to receiving the distillate is the amount of hydroxid that has been converted into carbonate, and from this the quantity of carbon dioxid may readily be calculated. A check on the work may be made by titrating the yellow color, and the difference between the appearance of the pink and the appearance of the yellow is the amount of hydroxid in combination with carbon dioxid. This method, for use in the determination of available carbon dioxid in baking powder, could be modified by placing the powder in C without water and introduc- ing water gradually through the funnel tube and afterwards heating it as de- IIA scribed. -/. C. Mims. Page 100, 1, (a), (3).— It is conven- ient to introduce sample wrapped in a cartridge in tissue paper into the dry fla.sk. The tissue paper may be col- ored with litmus or strips of litmus paper may be introduced at the same time. When the baking powder is badly made and contains excess of the acid ingredient this is indicated by the litmus remaining red at end of opera- tion. Usually the sodium carbonate is in excess, and the paper remains blue. Page 101, 1, (b), (3).— I find that 4 grains of a baking powder may safely and conveniently be employed in deter- mining carbon dioxid. This reduces the factor needed to convert to per- centage and conduces, to accuracy. With a maximum value for baking powder this amount yields from 0.5 to 0.6 gram of carbon dioxid. Page 104, 2. — I find it convenient to determine the excess of sodium carbonate occurring in most baking powders by replacing the tubes after determination of the available carbon dioxid, adding acid to the decomposing flask, and continuing the operation without recharging. The carbon dioxid now obtained is that due to excess of sodium bicarbonate. — A. McGill. Page 104, 7. — We desire to make the following preliminary announcement of a method for the application of the polariscope to the estimation of tartaric acid in commercial products: The commercial products containing tartaric acid fall into three classes, corre- sponding to the three methods of analysis described below: Class I. — Tartaric acid and mixtures containing alkaline tartrates and calcium tartrate but no other optically active substances or materials capable of modifying the rotation of tartaric acid in am n ion iacal solution (e. g., alum, iron). To this class belong Iloclielle salt, potassium tartrate, cream of tartar, calcium tartrate, and many effervescing i (reparations of the Pharmacopoeia. FIG. 7.— Mims' apparatus for the determination of carbon dioxid. 158 PROVISIONAL METHODS FOR ANALYSIS OF FOODS. Class II. — Mixtures of the above (I) with sugar. To this class belong many of the effervescing compounds of the Pharmacopoeia and most of the similar proprietary preparations. Class III. — Mixtures of members of Class I with modifying agents and traces of optically active substances. To this class belong mixtures containing alum, those containing traces of iron and aluminum, and those of which starch is a constituent, the latter containing almost invariably traces of active substances soluble in cold water. Consequently all baking powders and mixtures of cream of tartar with cream of tartar substitutes fall into this division. METHODS OF ANALYSIS. Class I. — The method employed in the analysis of materials of this group is based on the fact that in the presence of excess of ammonia the rotation of the solution is proportional to the concentration of the tartaric acid, and is independent of the other bases and acids present. (a) The substance is completely soluble in dilute ammonia. — A weighed quantity of the material containing not more than 1 gram tartaric acid is placed in a 25 cc measur- ing flask, moistened with 3 or 4 cc of water, and cone, ammonia (sp. gr. 0.880) added in quantity sufficient to neutralize all acids that may be present and leave about 1 cc in excess. The actual amount of the excess is not of importance, but a greater quan- tity than 1 cc of free ammonia should be avoided. The solution is then made up to 25 cc with water, filtered, if necessary, through a dry filter, and measured in a 20 cm tube in the polari meter. The amount of tartaric acid (C4H6O6) in grams (y) in the material taken is given by the formula: ?/=0.00519a; where x is the rotation in minutes. (b) The substance is not completely soluble in dilute ammonia. — In this case calcium tartrate is probably present and may be determined as follows: Treat 1 gram of the substance (or an amount containing not more than 1 gram tartaric acid) in a small beaker with 15 cc of water and 10 drops of cone, hydrochloric acid. Heat gently till both the potassium and calcium tartrates have passed into solution, and then, while still hot, add 2 cc of cone, ammonia (or enough to produce an ammoniacal smelling liquid) and about 0.1 gram of sodium phosphate dissolved in a little water. Trans- fer to a 25 cc measuring flask, cool, make up to the mark with water, filter through a dry filter, and polarize the filtrate in a 20 cm tube. The tartaric acid is calculated from the formula given under (a). The precipitation of the calcium by means of sodium phosphate is not absolutely necessary, but when this is not done, in cases where the proportion of calcium in the sample is high, there is a great tendency for the calcium tartrate to crystallize out from the ammoniacal solution before the reading is made. The tartaric acid present as bitartrate of potash may be determined by proceeding as in (a), the calcium tartrate being practically insoluble in cold ammonia solution. The tartaric acid present as calcium tartrate is given, with sufficient accuracy for most purposes, by the difference between the results of (a) and (6). If more accurate results are required, the residue insoluble in ammonia in (a) may be dissolved in a little hydrochloric acid and treated as above with sodium phosphate and ammonia. It may be noted that the method given ^below, under Class III, is applicable to this class also, but in most cases the above procedure will be found simpler. Class II. — The determination of tartaric acid in substances of this class is an exten- sion of the method given under I. In ammoniacal mixtures containing both tartaric acid and sugar the rotation of each is unaffected by the presence of the other substance, and consequently the rotation of the tartaric acid may be obtained by subtracting from the total rotation that part due to the sugar. The cane sugar may APPENDIX. 159 be conveniently determined by Olerget's method, both readings (before and after inversion), however, being made alter addition of ammonia. Should the sugar in these materials have become partly inverted, the reducing sugar must be determined by Fehling's process, and due allowance made for it. Class III. — Direct readings of rotation in ammoniacal solution are inadmissible in analyses of the substances of this class on account of the influence of iron and aluminum on the rotation of tartaric acid, and on account of the small but unknown rotation of the trace of inverted starch. Accurate determinations, however, may be made in the presence of excess of ammonium molybdate in neutral solution. The latter substance has the property of greatly increasing the rotation of tartaric acid, so that by its use the small rotation of the inverted starch is made insignificant. It is to be noted, however, that this increased rotation is very sensitive to the presence of alkali and acid, and is, more- over, modified by phosphates. It is therefore necessary, in the first place, to remove the phosphoric acid, and, secondly, to bring the solution to a definite state of neutrality Hoth these results are attained by the following procedure, the details of which must be carefully adhered to: Solutions required. — The following solutions must be prepared, but need not be made up very accurately: Molybdate solution: 44 grains ammonium heptamolybdate in 250 cc. Citric acid solution: 50 grams citric acid in 500 cc. Magnesium sulphate solution: 60 grams MgSO4 . 7H2O in 500 cc. Ammonia solution: 80 cc concentrated ammonia (sp. gr. 0.880) in 500 cc. Hydrochloric acid: 60 cc concentrated hydrochloric acid in 500 cc. Methyl orange solution: Method of i »•<><•<'< Inre. — An amount of material containing not more than 0.2 gram tartaric acid, not more than 0.3 gram alum, and not more than 0.3 gram calcium superphosphate is accurately weighed and placed in a dry flask. To this, 5 cc. of citric acid and 10 cc. of molybdate solution are added and allowed to react with the substance for 10 or 15 minutes (with an occasional shake). Next, 5 cc. of mag- nesium sulphate solution are added and 15 cc. of ammonia solution stirred in. After a few minutes (not more than an hour) the solution is filtered through a dry filter, a slight turbidity of the filtrate being disregarded. To 20 cc. of the filtrate are then added a few drops of methyl orange and hydrochloric acid, from a burette, till the pink color appears ( '2 or .'> drops too much or too little are of no consequence). Finally, 10 cc. more of the molybdate solution are added to the pink solution, which now becomes colorless or pale yellow; and wrater is added to make up the volume to 50 cc. This s< dution, after filtering if necessary, is polarized in a 20-cm. tube. The amount of tartaric acid in grams (y) in the weight of substance originally taken is given by the following formula, in which x is the rotation in minutes: // = 0. 001086 x + 0.001601 */x. But if the rotation is not less than 40', the simpler formula, y = 0.0075 + 0.001 168 x, may be employed. The following table gives the tartaric acid in grams for every 10 minutes rotation: Rotation in minutes. Grams tartaric acid. Rotation in minutes. Grams tartaric acid. 10 0 016 90 0.1130 20 0 029 100 0 1246 30 0.0-115 110 0.1365 10 o 05:',:> !•>() 0. 1479 50 60 0.0667 0 077(1 i:,o no 0. 1596 0. 1710 70 . o ovc. I.MI 0. 1826 80 0. 10111 160 PKO VISIONAL METHODS FOB ANALYSIS OF FOODS. It may be mentioned that the temperature has practically no influence on the readings. — Edgar B. Kenrick, University of Toronto; Frank B. Kenrick, University of Manitoba. Page 106, 12, (b). — Has anyone ascertained how accurately a mixed precipitate of ferric and aluminum phosphates can be calculated into its components from its gross weight and (Al PO4=122; FePO4=151; P2O5=142) total phosphoric acid? Let x and ?/=Al P04 and Fe P04, respectively; then x-\-y=a\ . 142*' , 142 y and~24T+W^6- Page 107, 12, (d). — Would you not usually recommend the indirect calculation of K from the weight of mixed chlorids and total chlorin as being much less laborious than the precipitate of K2Pt C15?— A. Me Gill. FOOD PRESERVATIVES. Page 108, 3. — It would be well to note that chloroform is much more convenient than ether for these extractions. A more convenient way to apply the ferric chlorid test is to use a portion of the chloroform solution without evaporation. Shake this portion in a small test tube with about 1 cc of water, and add a very small drop of weak ferric chlorid solution; the violet color will be observed in the aqueous layer above the chloroform if salicylic acid is present. Successive small drops of ferric chlorid should be added until the deepest color is obtained or until it is evident that salicylic acid is not present. An excess of ferric chlorid must be avoided, as it tends to destroy the color; but, on the other hand, if the first addition of ferric chlorid does not produce the reaction, enough must be added to make sure that the color can not be obtained. Page 109, 4. — The oxidation method devised by the writer (see Bulletin No. 59, TJ. S. Department of Agriculture, Division of Chemistry, page60;orLeffmann's Select Methods in Food Analysis, 1901, page 98), based upon the oxidation of benzoic into salicylic acid (Hanriot, C. R. 102, page 1250), has been in use in this laboratory for nearly three years with good results, and I think it worthy a place in our methods. Recently Mr. J. O. LeBach, food chemist of this station, has simplified the manipulation by doing away with the cooling in ice water and performing the oxidation in a test tube instead of a dish. Mr. LeBach describes his method of making the test as follows: Transfer about 0.05 gram to 0.1 gram of the dry residue from the chloroform or ether extract of the suspected sample to a test tube holding about 50 cc; add from 5 cc to 8 cc of concentrated H2S04, shake until the mass is dissolved, then add from 0.5 to 0.8 gram of barium peroxid, a little at a time, shaking and cooling in water after each addition of the peroxid. After all the barium peroxid has been added a per- manent froth should have been formed on the sulphuric acid. Let stand from 20 to 30 minutes, then fill the test tube three-fourths full of water, shake and cool rapidly to the temperature of the room. Filter off the barium sulphate and extract the filtrate with chloroform or ether. Draw off the chloroform and test it for salicylic acid in the usual way with dilute ferric chlorid. It is important that during the oxidation of benzoic acid to salicylic acid with barium peroxid the temperature of the solution should not go higher than ordinary temperature; the cooler the better. I have been able to oxidize benzoic acid to salicylic acid with commercial hydrogen peroxid, but have not found the method as easy to control as the one given above. Ammonium persulphate works as well in most cases, but sometimes fails to act properly. With barium peroxid I have never had a failure. We find that saccharin, when oxidized in this manner, gives the salicylic acid re- action. It is therefore necessary, before applying this test, to determine by the taste whether saccharin is present. Of course it is necessary also first to prove the absence of salicylic acid. — Alfred M. Peter, INDEX. A. Acetyl value, determination 28 Acidity, determination 96, 77, 104 Acids, fatty, determination of free 27 of melting point 31 estimation of liquid and solid 28 fixed, determination 64, 84 insoluble, determination 27 mineral, detection of free 77, 65 determination 65 soluble, determination 27 total, determination 52, 63, 83, 94 volatile, determination 52, 64, 77, 84, 94 Agar agar, detection 81 Alcohol, determination 65, 71, 72, 76, 82, 96 extract, determination 56 precipitate, determination 79 Aldehydes, determination 97 Alkalinity, determination 63 Alum, detection 106 Ammonia, determination 107 Annato, detection 39 Ash, determination 10, 17, 45, 55, 63, 69, 72, 76, 83, 94, 96 examination 63, 69, 77, 106 B. Baking powders, acidity, determination 104 alum, detection 106 ammonia, determination 107 ash, examination 106 carbon dioxid, determination 98, 104 phosphoric acid, determination 107 potassium bitartrate, determination 105 starch, determination 105 sulphuric acid, determination 107 tartaric acid, determination 104, 106 Barium, determination 88 Baudoin test for sesame oil 34 Bean*, coloring matter, detection 52 Beer, acids, total and volatile 94 alcohol, determination 92 ash, determination 94 16648— No. 65—0^ 11 161 162 INDEX. Patre. Beer, carbon dioxid, determination 95 dextrin, determination 94 degree of fermentation, determination 94 extract, determination 92 glycerol, determination 94 phosphoric acid, determination - 94 preservatives, detection 96 protein, determination 94 wort, determination of original gravity 93 Benzoic acid, detection 89, 109 Beta-napthol, detection 90 Boric acid, detection 16, 110 Brandy drops 44, 49 Butter, coloring matter, detection '. 40 fat, determination 38 microscopic examination 39 process, special tests 38 Reichert-Meissl number, determination 38 saponification value 38 the Waterhouse test for oleomargarine 38 water, determination 38 C. Candied or sugared fruits 44 Cane sugar, determination 71 Caramel, detection 98, 120 test 71 Carbohydrate foods 42 Carbon dioxid, determination 56, 95, 98, 104 Catsups, coloring matters, detection 52 Cereal products, examination methods 41 Cheese, fat, determination 40 separation for examination 40 nitrogenous compounds, determination water, determination 40 Chocolate. (See Cocoa. ) Cholesterol, determination Citric acid, determination 80 Cochineal, detection 1 20 Cocoa, and its preparations 54 Coffee and tea 55 Coloring matter. (See also Tannin. ) acid magenta, determination 114 caramel, detection 120 coal-tar colors, detection by extraction with solvents 113 coal-tar dyeing test 11 1 cochineal, detection 120 detection 1 6, 36, 50, 52, 65, 71, 74, 80, 88, 98 heavy metals, determination Ill Martin's yellow or napthalene yellow test organic, Rota's method of identification 114 turmeric, detection vegetable, determination 120 INDEX. 163 Page. Confectionery 43 alcohol, determination 49 cane sugar, determination 48 coloring matter, detection 50 commercial glucose, determination 48 ether extract, determination 46 mineral adulterants, determination 45 nitrogen, determination 40 paraffin, determination 46 polarization 47 starch, determination 46 sugar, determination 48 water soluble 47 Coumarin and vanillin, determination 69 Cream of tartar. (See Potassium bitartrate. ) Crude fiber. (See Fiber. ) D. Dextrin, determination (see also Gum) 42, 78, 94 Dextrose, determination (see also Sugar, reducing) 43 Dulcin. (See Sucrol. ) E. Ether extract, determination 10, 46, 56 Ethereal salts, determination 98 Extract, cold water, determination 59 determination (see also solids) 83, 92, 96 F. Fat, cheese, separation 40 determination (see «/w Ether extract) 17, 36, 38, 40, 42 Fats, edible (see also Oils), 40 Fermentation, degree, determination 94 Fiber, determination 58 Fluoborates, detection 92 Fluorids, detection 91 Fluosilicates, detection 92 Formaldehyde, detection 36, 65, 79, 107 Fruit juices. (See Jellies. ) Fruits and fruit products 74 acidity, determination 77 alcohol precipitate, determination 79 artificial sweetening materials, detection 80 ash, determination 76 examination 77 cane sugar, determination 78 coloring matter, detection 80 dextrin, determination 78 irrhitin, detection 81 heavy metals, determination 81 insoluble solids, determination 76 nitrogen, determination 77 preservatives, detection 80 sugar, determination ~ solids, determination 75 INDEX. Page. Fruits and fruit products, starch, detection 81 tartaric, citric, and malic acids, determination 79 candied 44 canned. (/See Jams. ) fresh 75 sugar-coated 44 Furfurol, determination 98 Fusel oil, determination 96 G. Gelatin. (See Proteoses. ) detection 36. 81 determination .. 19 Gherkins, coloring matters, detection 52 Glucose, determination 48, 85 Glycerol, determination 72, 82, 94 Glycogen, determination 19 Pfluger and Nerking method, determination 13 Gum and dextrin, determination (see also Dextrin) 86 H. Hehner number, determination 27 Hehner's method for free mineral acid 64 Heidenhain's carbon dioxid apparatus 100 Hilger's method for free mineral acids 64 Honey. (See Molasses. ) Infant and invalid foods 41 added sucrose, determination 42 carbohydrate 42 condensed milk 42 dextrin, determination 42 dextrose, determination 43 fat, determination 42 invert sugar, determination 43 maltose, determination 43 protein, determination 42 sugar, determination 42 water, determination 42 lodin absorption, Hiibl's method, determination 24 Iron and alumina, determination 106 J. Jams 75 Jellies, solids, determination 75 juices. (See Jellies. ) K. Knorr's, carbon dioxid apparatus 99 Koetstorfer number 26 Kremla's insoluble solids, method for the determination 76 L. Lemon extract 71 alcohol, determination 72 ash, determination 72 INDEX. 165 Page. Lemon extract, coloring matter, detection 1 74 glycerol, determination 72 methyl alcohol, detection 72, 73 refraction of precipitated oil 74 residue, determination 71 specific gravity, determination 72 Lemon oil, determination 73, 74 Lime, determination 56,106 Liquors, distilled, acidity, determination 96 alcohol, determination 96 aldehydes, determination 97 ash, determination 96 coloring matter, determination 98 ethereal salts, determination 98 extract, determination 96 furfurol, determination 98 fusel oil, determination 96 specific gravity, determination 96 sugar, determination 96 fermented, methods for examination 81 Lozenges and other pulverizable confectionery 46 M. Magenta, determination 114 Malic acid, determination 80 Maltose, determination 43 Maple sirup. (See Molasses. ) Marmalades. (See Jams. ) Martins yellow, test 114 Maumene number 31 • Meat, ash, determination 10 bacterial products 8 bases, determination 12 coloring matter, detection 16 ether extract, determination 10 extracts, ash, determination 17 fat, determination 17 fiber, determination of meat 17 gelatin, determination 19 glycogen, determination 19 nitrogen, determination 17 peptones, determination 19 preservatives, detection 19 proteids, determination of coagulated 18 proteoses and gelatin, determination 18 proteoses, peptones, and gelatin, determination 18 sample, preparation 17 syntonin, determination 18 \vater, determination 17 glycogen, determination ( Pfliiger and Nerking method) 13 metals, poisonous 8 nitrogen, determination of total 10 p< >is< mous, examinat ion 7 166 INDEX. Page. Meat, potassium nitrate, determination 14 preservatives detection 16 proteids, coagulated . 10 proteoses, peptones, and gelatin, determination 11 sample, preparation 9 species of animal 7 starch, determination 12 sugar, determination 14 connective tissue, determination 11 trichinae 8 water, determination 10 Melting point, determination 30 Metals 65 determination . 8, 52, 65, 81, 87, 111 Methyl alcohol, detection 72, 73 M'Gill method for determination of starch in baking powder 105 Milk and cream, colors, detection of foreign 36 fat, determination 36 gelatin, detection 36 preservatives, detection 36 solids, determination of total 36 condensed 42 3lolasses and sirup 43 commercial glucose, determination 48 polarization 47 sirups and honey, total solids, determination 44 N. Naphthalene yellow, test .' 114 Nitrates, detection 88 Nitrogen, determination 10, 17, 46, 59, 77 Nitrogenous compounds, determination 41 Nuts, sugar-coated 44 Oils, acetyl value, determination 28 Bechi test 33 distillation process 28 free fatty acids, determination 27 Halphen reaction for cotton-seed oil 32 index of refraction, determination 22 insoluble acids or Hehner number, determination 27 iodin absorption (Hiibl's method) 24 Kcetstorfer or saponification number 26 liquid and solid fatty acids 28 Maumen6 number 31 melting points, determination 30 melting point of fatty acids, determination 31 microscopical examination 35 peanut 33 phytosterol and cholesterol, determination 29 resin, determination 32 sesame, detection 34 INDEX. 167 Page. Oils, soluble acids, determination 27 specific gravity, determination 20 unsaponifiable residue, determination 29 Oleomargarine, Waterhouse test 38 Oxalic acid, determination 65 P. Paraffin, determination 46 Peas, coloring matter, detection 52 Peptones and gelatin. (See Proteoses.) determination 19 Phosphoric acid, determination 86, 94, 107 Phytosterol, determination : — 29 Pickles, coloring matter, detection 52 Potash and soda, determination 107 Potassium, bitartrate, determination 87, 105 nitrate, determination 14 sulphate, determination 86 Preservatives, detection 16,19, 65, 80,88, 96, 107 Preserves (See Jams. ) Proteids, coagulable, determination 18 coagulated 10 Protein, determination 42, 87, 94 Proteoses and gelatin, determination 18 determination 19 peptones and gelatin, determination 11, 18 R. Refractive index, determination 20 Reichert-Meissl number, determination 38 Rota's organic coloring matter, method 114 Saccharin, detection 51, 109 Saccharine products 43 ash, determination 45 Saffron, detection 39 Salicylic acid, detection 89, 108 Saltpeter. (See Potassium nitrate. ) Sand, determination 56 Saponification value, determination 26, 38 Sirup. (See Molasses. ) Sodium chlorid, determination 86 Solids, determination (see aho AVater ) 35, 44, 63, 69, 71 , 75, 92 insoluble, determination 76 Solubility, determination 63 Specific gravity, determination 20, 63, 72, 82, 92, 96 Spices, alcohol extract, determination 56 ash, determination 55 carbon dioxid, determination 5(> copper-reducing matters, determination 57 ether extract, determination ' 56 filter, i let en i) ination , "'s 168 INDEX. Page. Spices, lime, determination 56 microscopical examination 60 nitrogen, determination 59 piperin, determination 59 sand, determination 55 starch, determination 57, 58 sulphur, determination ". 56 tannin, determination 59 water, determination 55 water extract, determination 59 Starch, detection 81 determination 12, 46, 57, 58, 105 Sucrol, detection : 89 Sucrose, added, determination 42, 48, 78, 85 Sugar, determination 42, 84 invert (see also Sugar, reducing) 43 reducing (see also Dextrose) 14, 48, 78, 85, 94, 96 Sugar-coated fruits and nuts 44 Sulphites, determination. (See Sulphurous acid.) Sulphur, determination 56 Sulphuric acid, determination 107 Sulphurous acid, detection 16, 51, 108 free, determination 90 total, determination 90 Sweetening materials, artificial, detection 51, 80, 89, 109 Syntonin, determination 18 T. Tannin, determination 59, 86 Tartaric acid, detection 104 determination 80, 87, 104, 106 Tea and coffee 55 Tissue, connective, determination 11 Tocher test for sesame oil 35 Tomatoes, coloring matter, detection 52 Turmeric, detection 120 V. Vanilla 69 alcohol, determination 71 ash, determination 69 examination 69 cane sugar, determination 71 coloring matter, test 71 coumarin and vanillin, determination 69 solids, determination 69 Vanillin, distinction of solution from vanilla extract (see also Coumarin) 70 Vegetables, canned, total and volatile acidity, determination '. 52" coloring matter, detection 52 heavy metals, determination : 52 microscopic examination proximate analysis 51 INDEX. 16V) Page. Vegetables, saccharin, detection 51 soaked 54 sulphite, determination 51 Villivecchia, test for sesame oil 34 Vinegar, alcohol, determination 65 ash, determination 63 calculation of results 62 coloring matter, detection 65 foreign pungent materials, detection ., 65 free mineral acids ' 65 metallic poison, detection and determination 65 oxalic acid, determination 65 preservatives, detection 65 solids, determination 63 specific gravity, determination 63 total acidity, determination 63 - variety, determination 66 volatile and fixed acids, determination 64 W. Water, determination (see also Solids ) 10, 1 7, 38, 42, 55 Waterhouse test for oleomargarine 38 Wine, acids, determination 84 alcohol, determination 82 ash, determination 83 barium and strontium, determination 88 beta-iuiphthol, detection 90 cane sugar 85 commercial glucose 85 cream of tartar, determination 87 extract, determination 83 foreign coloring matter, detection 88 glycerol, determination 82 gum and dextrin, detei urination 86 heavy metals, determination 87 nitrate, detection 88 phosphoric acid, determination 86 polarization 84 potassium sulphate, determinate >u 86 preservatives, detection 88 protein, determination 87 reducing sugars 85 sodium chloric!, determination 86 solids, determination 83 specific gravity, determination 82 sugar, determination 84 sulphurous acid, determination 90 tannin and coloring matter, determination 86 tartaric acid and tartrates, determination 87 original gravity, determination 93 liii;4s— No. Ho— 02 12 O