T H E J O L ' R f l 1 L O F I S D l ' S T R I A L A-VD E N G I N E E R I N G C H E M I S T R F
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tion a t room temperature. The total quantity of material dissolved was found by filtering t h e solution through a Gooch filter and weighing the residue, and t h e potash was determined by t h e chlorplatinic acid method. The quantity of sample used was o . j o o o g. and t h e volume of t h e sol.vent 2 0 0 cc. The determinations showed t h e following results: P E R C E N T OF P O T A S H
DISSOLVED
On basis On basis of TOTALMATTER of sample KzO present DISSOLVED 0 . 5 t o 0 . 2 5 mm. 3.7 41.7 16.4 0.25 to 0.10 5.1 57.0 18.8 O.lOto0 6.7 75,2 25.8 O.lOtoO 6.8 76.4 26.z 0 . 5 t o O(a) 4.7 52.2 26. I ( a ) This sample consisted of a mixture of t h e first three grades of fineness in t h e ratio of 5. 36 and 58 per cents,
FIHEXESS
OF S A M P L E
From these results i t is evident t h a t potash may be dissolved from leucite rocks by means of sulfurous acid. This shows a possibility of an important industrial application since it indicates t h a t smelter fumes. containing sulfurous acid gas, may be used directly for recovering potash from leucite. Of course i t is known t h a t sulfuric acid m a y be used for that purpose, b u t there is a demand among opera-. tors of smelters for a method of using sulfurous acid gas t h a t does not involve the expensive installation required t o convert it into sulfuric acid. I t happens also t h a t t h e leucite of the Leucite Hills occurs in a region accessible in a general way t o t h e smelters of Utah, Colorado and I l o n t a n a . It may be possible t o devise methods whereby smelter fumes can be passed over or through the leucite rocks, in the presence of water, and the potash thus gradually leached out, perhaps with t h e minimum of installation and manipulation. I t is recalled t h a t t h e Wyoming leucite rocks are porous, somewhat resembling pumice. This fact may operate t o facilitate t h e percolation of the material and t h e leaching of the potash. I t is observed, furthermore, t h a t the dissolution in sulfurous acid is selective. Thus, while other materials are dissolved from t h e rock, the potash is dissolved in t h e greatest relative proportion. I t has been shown t h a t the quantity of potassic rocks in the Leucite Hills region is very great, the potash therein contained being estimated b y Schultz and Cross a t 197,349,617 tons. T h a t large quantities of sulfurous acid gas are available a t the western smelters is of course well known. BZREAUO F
SOILS
1.: S . DEPT. OF AGRICULTURE
WASHINGTOX _ _ I _ _
A NOTE ON THE CAUSE OF THE PLNK COLOR OBSERVED IN CERTAIN HYPOCHLORITE BLEACHING SOLUTIONS By H. G. ELLEDOE Received M a y 17, 1916
When sodium hypochlorite bleaching solutions are prepared for use in laundering, b y treating a solution of calcium hypochlorite, or bleaching powder, with a solution of t h e so-called neutral washing powder,' after t h e calcium carbonate has settled out, 1 These sodas are usually of about the following composition: normal sodium carbonate, 46.3 t o 36.1 per cent; sodium bicarbonate, 37.7 t o 50.0 per cent; and water, 16.0 t o 13 per cent. See Faragher, THISJOWRNAI,. 6 (1914). 641. T h e observations of Faragher have been confirmed a n d extended b y the writer.
Val. 8 , NO.ci
a pink colored solution invariably appears. This coloration has been observed when various trade brands of bleaching powder were employed, some of which were of American manufacturers and others of English origin; in fact. it seems t o result in every case where an excess of the HCO, ion is present n the solution. When bleaching solutions were made of the same bleaching powders, b u t , instead of t h e "washing sodas" mentioned, soda ash or sodium sulf a t e was used t o precipitate the calcium, the color of the resulting solution was green. By agitating this green solution with sodium bicarbonate, the pink color was again obtained. When certain laundries adopted soda ash as the washroom alkali, t h e wash-room help thereof were concerned about the absence of the pink color which, through habit and also because of the influence of the sales agents of certain alkali companies, they had come t o regard as a n index t o the bleaching qualities of the solution. Owing t o this condition, the writer was requested by the ,Illegheny County Laundrymen's Exchange t o explain the origin of the coloration a n d t o ascertain definitely whether there was a n y difference in the bleaching properties of the green and pink solutions. As was t o be expected, it was found t h a t equal volumes of the solutions, when made up with identical weights of t h e same bleaching powder, gave the same values for available chlorine. Among others, bleaching tests on hemp strings indicated t h a t one solution was as satisfactory as t h e other for laundry bleaching. The writer was led t o conclude t h a t t h e color of t h e pink solution was attributable t o the presence of traces of sodium permanganate, the manganese being derived from t h e bleaching powders used. This conclusion was reached after certain experimenta' work, of which the following is illustrative: There were made u p t w o solutions of sodium hypochlorite of the same strength.' T o one of them a small amount of manganous sulfate was added; this produced no change in color. Then t o each of the solutions, I O g. of sodium bicarbonate were added; after thoroughly shaking and settling, the solutions both assumed a pink color, b u t the one t o which the manganous sulfate had been added possessed a much more intense color. By color comparisons, it was estimated t h a t 0 . 0 2 per cent t o 0.04 per cent of manganese in the bleaching powders would be sufficient t o produce this color. I t was early suggested t h a t the pink coloration might be caused b y the presence of small amounts of sodium ferrate. Therefore, solutions were prepared as above, and t o one of them, ferric chloride was added; then, t o both solutions sodium bicarbonate was added, as above. After the precipitates had settled, no difference could be observed in the intensities of t h e pink color of the different solutions. These and other experiments led t o the conclusion t h a t the color was due t o traces of manganese, which, b y t h e catalytic action of the bicarbonate on the hypochlorite, was oxidized t o 1 T h e soliltions were prepared by making a paste of 10 g. of bleaching powder and water, adding thereto 10 g. of soda ash, and, after thoroughly shaking in a flask, making t h e volume u p t o 250 cc. This is the strength usually adopted in the laundry for stock solutions.
S e p t . , 1916
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
t h e permanganate, and t h a t , for laundry purposes, this coloration was of no consequence. Subsequently, when t h e writer’s report became available,’ the contention was made b y a representative of one of t h e prominent alkali manufacturers t h a t t h e pink color was due not t o t h e presence of permanganate, b u t of a ferrate; and in order t o settle definitely the whole matter, the absorption spectrum of t h e pink bleaching solution was compared with t h a t of a solution of potassium permanganate of t h e same color intensity. The solution used was made four times t h e concentration* usually employed and, after all t h e precipitate had settled, a saccharimeter tube was filled with the clear pink solution. A similar tube was filled with potassium permanganate solution of same color intensity and the absorption spectra were compared; t h e y were found t o be identical. T o compare t h e t w o more carefully, t h e two absorption spectra were brought in view a t one time, b y means of the comparison mirror, and t h e positions of t h e lines v-ere shown t o be exactly the same. No a t t e m p t is made here t o account for t h e presence of t h e trace of manganese in t h e bleaching powder, b u t t h e writer feels t h a t he has offered positive evidence t h a t t h e color of t h e pink bleaching solutions is due t o t h e presence of sodium permanganate, and not of sodium ferrate, as some have maintained. MELLONINSTITUTE
OF I N D U S T R I A L
RESEARCH
PITTSBURGH
ON THE USE OF CERTAIN YEAST NUTRIMENTS IN BREAD-MAKING3 By HENRYA. KOHMAN, CHARLES HOFFMAN, T R U M A N M. GODFREY, LAUREN H. ASHE, AND ALFRED E. BLAKE Received June 7 . 1916
T h e work in bread-making a t t h e Mellon Institute was begun in 1911 through the establishment of the Ward Fellowships and t h e results will now be published in a series of contributions. One of t h e important problems studied in our bread investigations mas the effect of certain mineral salts (such as are commonly found in natural waters) upon t h e fermentatiT-e activity of t h e yeast in breadmaking. I t was found necessary b y t h e Ward Baking Company (who operate bakeries in several cities) t o change t h e quantity of yeast as well as t h e fermentation period of their dough batches in the different cities, in order t o produce a standard product, or nearly so, even though all t h e raw materials used were identical (being purchased through a central office). Upon investigation it was found t h a t variations in t h e activity of the yeast were due t o the differences in t h e mineral content of t h e waters used for making t h e bread in these cities. In t h e work reported in this paper t h e effect of mineral salts found in natural waters upon the fermentative power of the yeast, as well as t h e quantity of yeast necessary for leavening purposes, has been given particular attention and 1 T h e conclusions were reported b y bulletin t o t h e Allegheny County Laundrymen’s Exchange on April 17, 1916. 2 T h e solution of sodium hypochlorite was prepared with 40 6. of commercial calcium hypochlorite, 40 g . of soda ash, and 40 g. of sodium bicarbonate, made u p t o a volume of 250 cc. with distilled water. 8 A paper presented in abstract b y Henry A, Kohnian a t the Urbana Meeting of the American Chemical Society, April 19, 1916.
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close investigation. The mineral substances contained in flour, milk, yeast and other raw materials for bread mere investigated in detail also, using a large variety of combinations and proportions. Of t h e large number of substances investigated. those t h a t have a really significant effect upon t h e fermentation in bread are surprisingly few. The salts of t h e mineral acids, such as the chlorides, nitrites, nitrates and sulfates, exert practically no influence except when combined with a cation which in itself has an effect. The carbonates are especially common i n natural waters and as a class are objectionable in bread, since t h e y neutralize the acids of the dough and thus interfere with t h e progress of t h e fermentation. More particularly, t h e carbonates of magnesium and the alkali metals should be considered as being detrimental t o the fermentation of t h e yeast. T h e salts of potassium, particularly the phosphates, were expected t o exert a decided influence on t h e fermentation of bread, because these compounds constitute such a large proportion of the ash of yeast a h d are mentioned so frequently in connection with alcoholic fermentation. Hoyever, the potassium salts were found t o influence the fermentation of bread only very slightly, while the phosphates had no noticeable effect. This is t o be explained, no doubt, b y the fact. t h a t t h e ash of flour is rich in these salts, consisting of about one-third potash ( K 2 0 ) and one-half phosphoric acid (P205),which abundantly supplies t h e yeast. Because of their common occurrence in natural waters, t h e salts of the alkaline earth metals were studied in detail, with surprisingly interesting results. T h e calcium salts, especially, are of common occurrence in water and it is around these t h a t t h e most interesting results presented in this paper center. Besides t h e water problem, t h e utilization of stale bread was indicated as an important problem for research. One of the proposed methods for using stale bread comprised t h e cooking of t h e crumbs and t h e n digesting with malt. The starches were thus transformed into sugars and t h e gluten remained in flakes which could be separated b y filtration. From this gluten residue, by digesting with concentrated HC1 in the ordinary way, glutamic acid hydrochloride was recovered in considerable quantities. The effect of the glutamic acid upon the parent substance, gluten, in bread was found t o be a decidedly beneficial effect both upon t h e dough and upon the yeast. AiiIUONIUM SALTS
Like many other acids, glutamic acid matures or ages t h e dough and, in addition, increases the gas production of t h e yeast. This accelerating effect upon the yeast was observed in bread and likewise in fermenting cane sugar, dextrose, and malt extract. I n fermentation of this kind other acids failed t o increase t h e fermentation as did glutamic acid hydrochloride, so we were led t o believe t h a t it was not a matter of acidity but t h a t glutamic acid hydrochloride owes its accelerating effect t o its nitrogen content. With this idea in mind, we conducted baking experi-
