burnt alum, but he fought it for three years and beat the patentee. The manufacturers themselves wanted to burn it, and reduced the price to 3 cents; then witness went out of the business. It is manufactured in Buffalo and in New York City; the Pennsylvania Salt Company, the largest manufacturers, manufacture it in Chicago. The Grant Baking Powder Company manufactures its own, or used to. (70.)

3. Deceptive labels.-Professor MITCHELL says that alum baking powders are sold either under deceptive labels or not labeled at all as to their composition, and that while they are sold at wholesale at very low prices, they frequently reach the consumer at prices as high as that of cream of tartar baking powder, very frequently prizes being given with them which are supposed to be given for nothing. The dairy and food commission of Wisconsin ordered the arrest of a Milwaukee merchant who sold the inspectors 2 samples of baking powder, one for 20 cents a pound and the other, labeled "best" baking powder, but identically the same powder, for 50 cents, a china dish being given with it. The witness read the label used, which contained the words, "Warranted Cream of Tartar Baking Powder Company, New York, U. S. A.,” in such a way that the careless reader would read, warranted cream of tartar baking powder," the word "company" being on the lower line. The formula which would make cream of tartar baking powder is given, but there is no cream of tartar in the baking powder, nor is it made in New York. To comply with the Wisconsin law requiring such powder to be branded as containing alum, the manufacturers have left their deceptive label on the side and top, and stamped on the side in black letters, "This baking powder contains alum.' Professor Mitchell considers this one of the most flagrant cases of deceptive labeling. (107, 108.)

D. Cream of tartar.-1. Source and action.-Professor VAUGHAN, dean of the medical faculty of the University of Michigan, says the baking powders most commonly sold in this country are the tartrate and the alum baking powders, and that the ideal baking powder is the tartrate, consisting of the acid tartrate of potash, obtained from the grape. When the wine ferments, the tartrate, being less soluble than the alcohol, is precipitated, and is then taken and purified and mixed with bicarbonate of soda, and a little starch to keep it dry and to act as a filler. In making bread the acid tartrate decomposes and sets free carbonic acid, which leavens the bread and improves its digestibility, because the gastric and other juices get into the pores better. He thinks there can be no objection to the use of tartrate baking powder; the Rochelle salts formed by the action of the tartrate of potash on the bicarbonate of soda are not injurious, but are beneficial. (205, 206.)

Dr. WILEY says cream of tartar is made from grapes. It is the acid principle of the grape, made from the argols which settle in casks and bottles of wine. He would not say that it would be wholesome in excess, nor would he call it injurious.

(47.)

Professor MALLET states that cream of tartar is the bitartrate or acid tartrate

of potassium obtained from grapes. As the fermentation of wine progresses, the wine becomes less and less capable of holding the tartar in solution, and crusts of argol or crude tartar are formed in the casks. Cream of tartar is obtained by dissolving and crystallizing this argol. Some cream of tartar is also obtained from the spent yeast or lees or dregs of the wine vats. The whole supply comes from the wine-producing countries. Some, but not much, is obtained from the wine industry in the United States. (553, 554.)

Professor PRESCOTT says cream of tartar is a constituent of fruits, especially the grape. The acid salts of fruits are among the most wholesome and important constituents of human food, and when entirely lacking leave sailors and soldiers victims of scurvy. Cream of tartar has a high rank as a wholesome article of food, both in itself and in what it leaves behind after the process of baking. This residue is Rochelle salts, which in the doses in which it occurs in food has only that favorable effect which fruits have. (200.)

Mr. PETRAEUS, a chemist, says that cream of tartar baking powder produces 70 per cent of sodium potassium tartrate, which is the basis of Rochelle salts. (292.) Dr. MCMURTRIE states that the residue left in bread by the use of cream of tartar baking powder is sodium potassium tartrate. This is disposed of in the process of digestion "in exactly the same way as other vegetable substances of like character, and is digested in exactly the same way as sugar." The tartaric acid radical is broken up into carbonic acid and water, and the alkaline radical passes into the blood, supplying the necessary alkaline constituents of it, and is eliminated by the kidneys, tending to correct any unfavorable acidity of the fluids of the body. The amount of tartrates in an ordinary loaf of bread made with cream of tartar baking powder may be equivalent to that contained in a pound and a half of ripe grapes. (594, 595.)

Professor MALLET says that he has never directly investigated the wholesomeness of cream of tartar baking powder, but he has no reason to believe that it is unwholesome. He can imagine a case in which a large amount of cream of tartar might be injurious, by rendering the urine alkaline and causing precipitation of the earthy phosphates. On the other hand, many people with a tendency to uric acid deposition from the urine are benefited by the production of such an alkaline character.

(554.)

2. Adulteration and substitution.-Dr. MCMURTRIE, consulting chemist for the Royal Baking Powder Company, the Cleveland Baking Powder Company, and the Price Baking Powder Company, states that the cream of tartar which is used by these companies in the manufacture of their powders does not vary appreciably from a purity of 100 per cent, and that the other ingredients used in their products are of a similar high degree of purity. (594.)

Dr. WILEY bought 7 samples of cream of tartar in New York City, 2 or 3 in drug stores, and the rest in groceries. Three of the samples were cream of tartar, one contained 93 per cent of cream of tartar, and one 24 per cent. The other two were phosphate of calcium and calcium sulphate combined, without a trace of cream of tartar. This combination is the substance which is known in the trade as c. t. s., or cream of tartar substitute, but they were not labeled as substitutes. They were sold by the retailer as cream of tartar, and at the price of cream of tartar, 50 cents a pound. (584.)

Professor MITCHELL, chemist to the Wisconsin dairy and food commission, says that as a rule the cream of tartar purchased by the Wisconsin inspectors in drug stores was of high grade, generally having a large amount of actual cream of tartar in it, and was much more nearly worth the price paid than the samples purchased of grocers, which as a rule were not cream of tartar to any great extent, 80 per cent being substitutes generally composed of acid phosphates of lime and alum mixed with starch, and sometimes small amounts of cream of tartar. In a few samples there were possibly natural impurities in large amounts-tartrate of lime and sulphate of lime-small amounts of which were also present in some of the drug-store samples. The substitutes for cream of tartar are generally sold as phosphatic cream of tartars. The jobber buys them of the manufacturer as phosphatic tartrates, but sells them to the grocer as cream of tartar, or did so in Wisconsin until investigated. Professor Mitchell much prefers cream of tartar to an alum substitute, and does not think alum suitable for food. (117.)

Professor Mitchell says acid phosphate of lime is made either from bone phosphate or from natural rock phosphate by treatment with sulphuric acid, and is generally mixed with flour or starch to prevent caking. (117, 118.)

Mr. MURRAY says a certain line of goods are considered commercial goods, such as commercial cream of tartar, some of which has not very much cream of tartar in it. This costs about 5 cents a pound, while the pure is worth about 214 cents a pound. (67.)

Professor FREAR says that a very large proportion of the samples of cream of tartar examined by him consisted either of terra alba, or terra alba with a little free tartaric acid, or cream of tartar diluted with terra alba or with acid calcium phosphate. (529.)

E. Composition of alum baking powder.-Professor MALLET, professor of chemistry in the University of Virginia, says that alum began to be used in baking powders in this country about 20 or 25 years ago. Alum is a very cheap material and it produces a good-looking bread. The alum baking-powder industry has consequently become very large. Some 5 or 6 per cent or more of phosphate of calcium is very commonly added to the alum baking powders. (551.)

Dr. WILEY says there are various forms of alum, which is a double salt of which alumina is one base and ammonia, potash, or some other metallic oxide the other. (46.)

Professor AUSTEN says that the material which is now commonly used in baking powders is not what is popularly known as alum. If a drug store orders alum, a potash alum is understood; and this was formerly used in baking powder. In making an alum baking powder, however, the evolution of gas must be so regulated that it will be given off slowly and in accordance with the temperature. If it goes off too quickly the bread swells up in a big bubble; if too slowly, it will not rise. It has taken a great deal of experimenting to produce a so-called alum preparation which will give exactly the same results in the evolution of gas as a cream of tartar or a phosphate powder. The alum which is now used in baking powders is c. t. s., or cream of tartar substitute, a calcined mixture of sulphate of alumina and sulphate of soda. C. t. s. is made, Dr. Austen believes, only by 3 very large chemical manufacturers. The baking-powder makers do nothing but put the materials, c. t. s., bicarbonate of soda, and starch or flour, into the

mixing machine. All the manufacturers of alum baking powder use substantially the same formula; the only difference is in the strength. (541, 542.)

Dr. MCMURTRIE says that alum baking powder consists of a mixture of soda alum, bicarbonate of soda, or ordinary baking soda, and about 60 per cent of starch. (596.)

Dr. McMurtrie says that 3 alums have been used for the making of baking powder. The first is potassium alum, double sulphate of alumina and potassium; the second, ammonium alum, a double sulphate of alumina and ammonium, and is less expensive than the first; the third, soda alum, the double sulphate of alumina and sodium, is less expensive than either. It is the last which is now chiefly used in the manufacture of alum baking powder. It is not generally sold under the name of alum, but is labeled and billed as c. t. s., which means cream of tartar substitute. The manufacturers of alum baking powder have often no knowledge of chemistry, employ no chemists, and have no means of knowing the composition of their materials except the statement of the manufacturer they buy from.

The first process in the manufacture of alum is to treat the mineral known as bauxite with sulphuric acid. The solution thus obtained is evaporated to a proper density and mixed with a solution of soda. When the mixture cools the 2 substances, alumina sulphate and sodium sulphate, crystallize together, forming what is known as soda alum. A considerable amount of water is taken up in the process of crystallization. The water is driven off by heat, and a porous matter remains, which is called "burnt alum." This burnt alum, when pulverized, is the substance which is used in the baking-powder manufacture. In order to have a product which corresponds exactly with the theoretical composition of sodium and alumina sulphate the greatest care must be exercised in the manufacture. It generally happens that some of the acid constituent of the compound is driven off in the process of burning, and we have in the finished product some uncombined or partially saturated alumina. The product obtained in this way can not, therefore, have a constituent composition. Its power to decompose the bicarbonate of soda when used in baking powder must be variable. It is readily understood, therefore, why the manufacturer of the alum should in sending each lot to his customer indicate what its neutralizing power is, and why the manufacturer of baking powder must accept what the alum manufacturer tells him, and why the baking powder must have an uncertain and variable composition. (595, 596.)

Professor MALLET states that the greater part of alum is now obtained from bauxite, a native hydroxide of aluminum. This is treated with sulphuric acid of a certain strength, sulphate of sodium is added, and the whole is evaporated until it sets in a crystalline mass on cooling. (554.)

F. Alum not found in natural foods.-1. Organic bodies.-Dr. WEBER mentions as an objection to alum baking powder that aluminum compounds do not occur in either the vegetable or the animal matters which are the sources of food for man. (605.)

Professor MUNROE believes that we should not use as food any substance which does not appear naturally in the vegetable or animal organisms. Cream of tartar occurs naturally in vegetation. Phosphates occur naturally in vegetables and animals. The salts of aluminum very rarely appear in the analysis of animal or vegetable material, and in the few cases in which it has appeared it has not been shown that its presence was not accidental. This is the more remarkable since aluminum is estimated to be the third element in abundance. (608.)

Dr. MCMURTRIE, consulting chemist of the Royal Baking Powder Company, asserts that no compound of aluminum is ever found in any flowering plant or any natural food of vegetable or animal origin. He has seen a single statement by a chemist in Japan that aluminum has been found in wheat; but he believes that the aluminum was introduced accidentally and was not contained in the grain itself. (599.)

2. Potable waters.-Dr. MCMURTRIE, consulting chemist of the Royal Baking Powder Company, says that aluminum compounds do not exist in potable wate in quantities sufficient to be taken into account. It has been said by Dr. Flint, and also by Dr. Smith, that certain public analysts in England, in determining the amount of alum which has been added to bread, make a correction of a grain and a half per pound of bread to correspond with the alumina in the water used. This would mean, according to Dr. McMurtrie, about 14 parts of alum in 7,000 parts of water. He has made inquiry among chemical experts who have had much to do with the examination of natural potable waters in the United States, and they declare that they have failed to find alumina in such waters in quantities exceeding 3 parts per million. (599,600.)

G. Chemical action of alum baking powder.-Dr. WILEY says alum is used in baking powder to free the carbon dioxide from the bicarbonate of soda. (46.) Professor HALLBERG says that alum baking powder leaves a residue of aluminum hydrate in the bread. The question as to the character of aluminum as an ingredient in baking powder is not yet settled. The authorities differ, and experts can be found to assume any view that the employer desires. (102.)

Mr. GEORGE C. REW says that, strictly speaking, alum means a double sulphate of an alkaline metal-aluminum. The substance left in food prepared with alum baking powder is hydrate of alumina and sulphate of soda, neither of which is alum, though alum may be manufactured from them. (104.)

Dr. MCMURTRIE says that when the baking powder is brought into contact with water, either by itself or mixed with flour, and the mass is cold, comparatively little action occurs. When heat is applied the sodium constituent of the bicarbonate of soda takes the place of the aluminum in the alum. Carbonic acid is liberated, and some chemists say that the aluminum is set free in the form of aluminum hydroxide and all of the sodium of the bicarbonate of soda is changed into sodium sulphate, which is also one of the constituents of the soda alum. The solid residue which remains in the bread is sodium sulphate and an aluminum compound. There are good authorities who believe that the decomposition of the alum is never complete, and that some unchanged alum always remains in the bread. (596.)

Dr. McMurtrie states that in the later pharmaceutical authorities in the United States alumina-that is, aluminum hydrate-is described as a medicinal agent and an astringent. In the dialysis of aluminum compounds the compound which is left behind is aluminum hydrate. It seems probable that it has an astringent effect upon the cells of the kidneys. (599.)

Professor MOTT found that the administration of bread made with excessive amounts of alum baking powder produced the same effects upon dogs as the administration of hydrate of alumina. Phosphate of alumina in large doses, though producing some physiological disturbances, had no such marked effects. Professor Mott concludes from these results that the alumina in biscuits made with alum baking powder must be, to a very great extent, in the condition of hydrate of alumina rather than phosphate. (628-631.)

Of the 17 brands of alum baking powder examined by Professor MALLET, all but 1 contained calcium acid phosphate as well as alum. In all cases in which phosphate was used nearly the whole of the aluminum was present as phosphate, and not as hydroxide (hydrate), after treatment with water. (561.)

Professor MOTT quotes from Professor Patrick, who considers himself to have proved the wholesomeness of alum baking powder, the admission that if bread is carelessly mixed with an insufficient amount of water, part of the flour, and with it part of the powder, remains nearly or quite dry, and after baking, such bread will contain a certain small amount of alum. Professor Mott asserts that there are few who make good bread, and therefore regards Professor Patrick's remark as equivalent to an admission that alum is likely to appear in alum baking-powder bread. (635.)

H. Solubility of aluminum hydrate.-1. Denied.-Mr. REW says that Francis Sutton, the English analyst, whom he considers the best authority who has ever investigated the subject, determined by experiments on living animals that hydrate of aluminum was not soluble in digestive juices, but was excreted in the same condition in which it was taken into the stomach; the sulphate of soda having almost identically the same physiological action as the Rochelle salts left by cream of tartar baking powder. Mr. Rew says aluminum hydrate is soluble in hydrochloric acid, but not in the weak hydrochloric acid of the stomach, according to Sutton's testimony in the Norfolk Baking Powder Case. (88, 104.)

2. Doubtful.-Dr. MEW, chemist to the Army Medical Department, says that it is quite uncertain whether aluminum hydroxide is dissolved in the stomach or not. Ordinarily it is practically an insoluble substance. In the human laboratory it may go into solution, possibly. If it does it may do harm; but Dr. Mew ows of no evidence that it does. (612.)

Professor MOTT refers to the experiments on cats, by which Professor Patrick thought he showed alum baking powder to be uninjurious. Professor Patrick fed cats with biscuits made with as large a proportion of alum baking powder as 6 teaspoonfuls to 1 quart of flour. From 20 minutes to 24 hours after eating these biscuits the cats were killed, and the contents of the stomach and of the small intestines were examined for dissolved alumina. Professor Patrick says that "in every case a large amount of sodium sulphate was found (in solution as was expected), and also a certain amount of hydrate of alumina undissolved." Professor Mott declares that the meaning of the statement that hydrate of alumina was found undissolved is not clear, and he does not think that Professor Patrick's

experiments, so far as they are explained, prove that hydrate of alumina is not dissolved in the stomach or is not absorbed into the system. (635.)

3. Affirmed.-Professor PRESCOTT thinks the most objectionable constituent of baking powders in this country is alum. As a salt of aluminum it contains an astringent which has a medicinal effect when applied with remedial intent, but is injurious when taken habitually and indiscriminately. In the mixing of bread sponge it undergoes a change, and doubtless some portion becomes very difficult of solution, so that not all of the alum comes into solution in the stomach; no one can tell how much. The alum is liable to go into solution, and if not fully dissolved when in the condition of aluminum hydrate or other compound of alum in contact with the acidulous or albuminous fluids of the stomach, it is liable to go into combinations with the digestive agents of the stomach and with the constituents of food, so as to have an effect as an astringent and a precipitant, which, though slight, tends to impair the sources of nutrition when continued from year to year. No two stomachs are in exactly the same condition. The chemical agents of solution in the stomach are too complex to be fully defined by chemistry at the present time. (196, 197.)

Dr. CRAMPTON says that the solubility of hydrate of aluminum and phosphate of aluminum in water or dilute acid is a question readily answered by any chemist, but their solubility in the various and complex alimentary fluids, and under the conditions of natural digestion in the human body, is quite another matter. Some experimenters have reported practically no solution, others a considerable amount. Improper proportioning of the different ingredients in the powder, and improper mixing of the powder in the dough, are likely to result in an imperfect reaction and in the appearance of more or less of the original salt in the bread. Considering this, as well as the various character of the solvents used and the different conditions, it is easy to understand the difference between the results of different experimenters; but it must be expected that at least small quantities of alum will be absorbed. (623,624.)

Professor MITCHELL, chemist to the dairy and food commission and the State board of health of Wisconsin, has failed to find any alum baking powder which would react perfectly and not leave some soluble alum. He says that there is no question but that hydrate of alumina is soluble in the dilute acids of the stomach in a normal condition, and his opinion is that it would be more or less soluble as a chloride, or at least liable to absorption, its tendency being to act as an astringent and possibly as a mild irritant as a drug, and not as a food. He would prefer either cream of tartar or phosphate baking powder. (108.)

Dr. WEBER says that aluminum hydroxide is itself a mild astringent, and is soluble in dilute acid, and consequently in the juices of the stomach, and that the salt thus formed acts in all respects like alum itself. (606.)

Professor FAIRHURST, of Kentucky University, says hydrate of alumina is soluble in the acids of the stomach. (620.)

Dr.MCMURTRIE asserts that it is indifferent whether any unchanged alum remains in the bread or not; for even if the reaction is completed in the manufacture of the bread the resultant aluminum compounds, under the influence of the several acids which are present in the gastric juice, must produce all the medicinal and therapeutic influences which are ascribed to alum. It has been proved that soluble aluminum compounds do exist in bread made with alum baking powder; but whether they exist in the bread itself, or whether they are formed by the reactions occurring in the stomach, the system may be subjected to the action of these soluble aluminum compounds when such bread is consumed. (596, 597.)

Dr. McMurtrie says further that Dr. Smith and Dr. Flint, upon whose experiments the statements of Dr. Austen are based (539,540) stated in their testimony in New York that they knew nothing about the disposition of aluminum compounds in the body when ingested with the food; that they knew nothing about the amount of alumina that was ingested; and that they were unable, therefore, to say whether the alumina passes through the alimentary tract unacted upon and inert, or whether it went into the blood and the circulation; and, if it did go into the blood and the circulation, whether it would be wholly excreted or whether it would remain deposited in the organs as a disturbing and injurious element. (598.)

Professor MUNROE, of the Columbian University, testifies that though aluminum hydroxide is but slightly soluble in water, it is soluble in lactic acid and acetic acid, which may occur in the stomach and may be produced during the process of digestion. He therefore believes that the alum product in bread is capable of a harmful effect. (609.) After making and artificially digesting bread in which alum baking powder was used Professor Munroe states, in a letter to Senator Mason, that his experiments show conclusively that hydrochloric acid of the strength found in the gastric juice of man will, at ordinary temperatures, dissolve