T H E J O U R X ; . 4 L OF I N D U S T R I A L AA-D EAYGIAVEERI-YGC H E - W I S T R Y
222
NO.
CC. O F T H E
DIGESTIONTO REDUCE25
30 minutes digestion
with h-aC1 n.ithout SaCl 23.2 17,s
CC. FEHLING’S SOLUTION 120 minutes digestion
with NaCl 45.5
without NaCl 30.3
Experiment 7.-Two grams soluble starch in 500 cc. water with different quantities of NaCl were saccharified with I O cc. koji extract a t 50’ c. After 30 min., I O cc. alkali solution and NaCl were added so that each solution contained I O O grams NaCl in total solution. REACTIONS TOWARD IODISE S o . of grams
S o . of solution
of XaC1 added before reaction 0
1
2
20
3
100
After 10 min. red purple purple
No. Cc. of sugar solution t o reduce 5 cc. Fehling’s solution 17.0
S o . of solution 1
2 3
In Nos.
After 30 min red red purple
26.0
45 . O
and 6 we see that the influence of NaCl depends upon the concentration and not on the ratio of starch to the enzymic quantity. The more dilute is a n enzymic solution the stronger is the inhibitory action of sodium chloride. From Exps. 6 and 7 i t is clear that the inhibitory action of NaC1 does not relate to dilution when the proportion of XaC1 t o enzym is constant. j
Mar., 1 9 1 3
other kind of diastase which produces glucose directly from starch without the aid of glucase. 11. Common salt has a protecting action on kojidiastase under heating but not on malt-diastase, while Na,HPO,, asparagine and H,SO, impair its activity more quickly. 111. The inhibitory action of salt on koji-diastase has a certain relation to the concentration of diastase. In a dilute enzymic solution i t is very strong but not in a concentrated enzymic solution. I t is therefore necessary in every case t o note concentration of diastase when we consider the influence of some salt upon it. I V . The activity of koji-diastase is conserved in brine for a long period. DEPARTMEST APPLIEDCHEMISTRY TOKYOIMPERIAL L~KIVERSITY
APPLICATION OF THE AMMONIUM CARBONATE METHOD FOR T H E DETERMINATION OF HUMUS TO HAWAIIAN SOILS’ B y J . B . RATHER Received A-ovember 12, 1912
S U M MARY
The ammonium carbonate method for the determination of humus in soils1 has been used on a number of samples of Texas soils, of different types met with in the United States, including the Travis, Orangeburg Houston, Laredo, Norfolk, Lufkin and Cameron series, and in every case the results have been entirely satisfactory, the “ a s h ” averaging less than 0.40 per cent. While this method has proved t o be reliable in this laboratory, it has been shown by Kelley and McGeorge~that on certain soils of Hawaii the method does not give good results. This is due t o the nature of the clay and not to the amount of clay present, for we have precipitated the clay completely in a solution containing 33.45 per cent. “ a s h ” as determined by the official method. Kelley and McGeorge modified the ammonium carbonate method by adding 4 grams ammonium carbonate per hundred cubic centimeters instead of 0.5 gram. This coagulated the clay in most cases, but they claim that the organic matter was partially precipitated. These investigators propose a method for the removal of the clay by filtration by means of reduced pressure through a Pasteur-Chamberland tube and washing with ammonia as was done by Alway, et al.4 I n connection with this i t might be of interest to state that the filtration of humus solutions by reduced pressure has been done by Fraps and Hamner,j who themselves do not claim originality for the process. Fraps and Hamner state that the method is very tedious and that organic matter may not pass through the filter. Neither Cameron, who first used the porcelain tube, Fraps and Hamner, nor Alway, et al., recommended the method.
I . Though koji may contain two different saccharifying enzyms, v i z . , amylase and glucase, the total quantity of the glucose in a saccharified solution could not be produced from maltose by the action of glucase alone; hence, koji must contain some
1 Under the general direction of G. S. Fraps, chemist. Read a t the meeting of the Association of Official Agricultural Chemists, Washington. D. C., September, 1912. THIS JOURNAL, 3, 660. I b i d , 4, 9, 604. 4 Nebraska Exp. Sta., Bull. 116. j Texas Exp. Sta , Bul..: 129.
IV. CAN KOJI-DIASTASE
BE PRESERVED I N B R I N E ?
The stability of the koji-diastase in brine is not yet well known and it is a very important factor in soya making, where a long period of activity is necessarily maintained. I have kept diastase in brine for a month in summer and compared it with that kept in a dried condition in a desiccator. The result was as follows: Experiment 8.-One hundred cc. of a 2 percent. starch solution was saccharified for 3.5 hours a t 50” C. with a n enzymic solution ( I gram Taka-diastase, 15 grams NaCl in I O O cc. water), and its reducing power was determined.
3-0.
1 In In 3 In 2
No. cc. of saccharified solution to reduce 25 cc. Preservation of Diastase Fehling’s solution brine ........ , . . , . . , . . . . . . . , . . . . . . . . . . . . . . . . . 30.8 dry condition with envelope of black glazed paper 2 8 . 3 dry condition in thin layer exposed to sunlight, . . . 3 3 . 4
I t will be seen from these results that the diastatic power of the enzym in brine was stronger than t h a t which was exposed to sunlight. The gelatine liquifying power of the same diastase was in the same order. From this and other data I have, I believe the strong diastatic power exerted in the old mash which was kept about a year was principally due to the koji originally used.
’
Xlthough the types of soil such as are found in Han-aii may not occur in this country, on account of the simplicity and convenience of the ammonium carbonate method it \vas thought desirable to secure such a modification as would include such soils. The soils used in this study XT-ere Hawaiian soils kindly furnished by M r . McGeorge. After a number of trials to ascertain the most suitable conditions, the following method was adopted: Prepare the solution as described in the official method, but decant the solution instead of filtering. Place roo cc. in a graduated flask, add 2 grams ammonium carbonate, and heat on the steam bath for one hour. Allow to stand over night, pipette off j o cc. of the supernatant solution, and evaporate to dryness in a tared dish. Dry three hours at 100' C . , weigh, ignite, and weigh again. The loss in weight represents the humus. The results for humus and humus ash are shown in the table along with the humus and ash by the official and original ammonium carbonate methods. All. determinations here reported were made on the same solutions. No. 6185
No. 6187 SU3I>l.iRT
c__hl---,
Hethod Official.................... Ammonium carbonate.. . . . . This modification.. . . . . . . . .
Humus 5.44 5.16
{::::
Ash 7.90 6,68 0.18 0.40
Humus 7.31 5.13 2.70 2.75
Bsh
'
34.80 17.20 0.10 0.18
The original ammonium carbonate method reduced the ash byabout 1 5 per cent. in No. 6185 and by about 50 per cent. in No. 6187. This modification of the ammonium carbonate method reduced the ash in sample No. 618j from 7.90 to 0.29 per cent., and in No. 6187 from 34.80 t o 0.14per cent. The humus which was j . 4 4 per cent. in No. 6185 by the
1
official method was reduced t o 3 . 7 4 per cent. by this modification of the ammonium carbonate method, and in S o . 6187 was reducedfrom i.31to 2 . 7 3 percent. The differences do not represent humus, but are probably entirely due to the loss of water on ignition of the hydrated clay and oxides of iron and aluminum. The solutions obtained by this modification were free from all turbidity. I t n-as found that with these soils the clay could not be filtered off and the aliquots mere therefore removed with a pipette. The introduction of the ammonium carbonate increases the volume of the solution. and after standing over night, it is about roo.; cc. This would make t h e results about 0 . 0 1 per cent. too lorn (in percentage of humus in soil). Since this is well within the limit of error with these soils, it is disregarded. The Hawaiian soils studied are said to be of volcanic origin and are very rich in iron. Although the original ammonium carbonate method gives unsatisfactory results with these soils, we believe soils of this type mill rarely be met with in the United States, since as stated before the method has given entire satisfaction on a number of the soil types of this country. The ammonium carbonate method for the removal of clay from humus solutions has given uniformly good results on a number of the soil types of the United States, but on exceptional soils, like some of those of Hawaii, a slight modification of the method is necessary to remove the clay. The modification consists essentially in increasing the amount of ammonium carbonate to z grams per hundred cubic centimeters, and heating for one hour. TEXASAGRICULTURAL EXPERIMEST STATION COLLEGESTATION, TEXAS
LABORATORY AND PLANT THE NEW HIGH FORM OF SULFURIC ACID CHAMBER B y F. J. FALDING AHD W. R. CATHCART Received January 20, 1913
Since the Sulfuric Acid Chamber-process has existed, the two important factors which have been uppermost in the minds of manufacturers, engineers, and chemists, are: F i r s t , economy of chamber space, which of course means economy of lead; and Second, economy of nitration. These economies have been accomplished in a very high degree and in a most satisfactory manner, by the use of a new form of lead chamber, which embodies a scientific principle heretofore ignored on account of a misconception of its importance. HISTORICAL O U T L I K E O F THE LEAD CHAMBER
The evolution of the Chamber-process is well known. At first intermittent-then continuous but without recovery of nitrogen oxides-next the addition of 1 Covered by U. S. Patent No. 932,771 and Canadian Patent No. 124,132, owned b y the Chemical Improvement Company. 220 Broadway,
New York City. Also patented in England, Germany, France, Belgium and other countnes.
I
Gay-Lussac towers, and finally the Glover tower. The chambers, however, have been always simply a series of enlargements of the flue or gas conduit connecting, at first, the sulfur burners with the outer air or exit, and later the Glover and Gay-Lussac towers. These enlargements of the flue retarded the speed of the gases, permitting them t o mingle and react. As the chambers have been almost universally *framed with timber construction, the height and width have varied principally in conformity with considerations of carpentry, a width of thirty feet and a height of twenty-four feet having been rarely exceeded; whereas a length of one hundred to two hundred feet or over, for each chamber, used to be quite common. Lead chambers have been constructed empirically, and of many shapes and sizes. Sometimes the gas would pass through from four to ten chambers in series having a total length of from four hundred to one thousand feet in all. The principal dintcmioii o j the chamber space has been always the horizoiztal axis in the yaiiie direction as the travel of the gas.
