Aug., 1919
T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
British, and American services for the purpose of organizing a commission which would study the questions of production and distribution of chemical warfare material, just as the previously described Congress discussed questions of research. Duplication of orders and difficulties in securing raw materials, of which, of course, each country would try t o get as much as possible without regard to the immediate needs of the others, made necessary the creation of some central organization which would regulate the flow of both raw material and manufactured products in accordance with the military requirements. This idea was nothing more than another manifestation of the generally felt need for pooling all allied resources, in order to meet effectively the ever increasing German menace, a feeling which culminated in the unity of command and the formation of the High Interallied Council. There were three representatives from each of the above-mentioned countries present: Gen. Ozil, Com. Bollaert, and Com. Perrot for France; Mr. Haigh, Capt. Moreland, and Capt. (later Major) Lefebure for the United Kingdom; and Col. (later Brig. Gen.) Fries, Capt. (later Major) Ward, and the writer for the American Expeditionary Forces. After some discussion the Commission proposed that meetings should be held every two or three months and that it should deal broadly with the following matters: I-The examination of allied chemical warfare manufacture and outputs, and of allied chemical warfare programs, with a view to ensuring that the demands concerned are covered. 2-The examination of the best utilization of allied factors in manufacture, such as raw materials, plant, processes, distribution of raw materials, tonnage, etc., with a view to meeting the program indicated. The Commission was to be represented by a permanent secretariat comprising: I-France, Com. Perrot 2-Great Britain-Capt. Lefebure j-The United States of America-the writer and it was to act purely in an advisory capacity. The organization plan was approved by the ministers o€ France and Great Britain and by the Commander-in-Chief of the American Eupeditionary Forces and thereafter the Commission met on three occasions, May 11, August g, and August 17. Owing to changes in the organizations in the allied armies, the personnel of the Commission was different a t every meeting, the secretaries and the chairman, Gen. Ozil, being the only members who were present a t all the meetings. Italy was asked to join and was represented by Col. Malvani a t the second session, Lieut. Cardoso acting as secretary. A certain routine was adhered to in all the meetings. Starting materials, such as chlorine, bromine, sodium cyanide, chloride of lime, etc., were first of all discussed in regard to actual production, plant, capacity, and contemplated increase or decrease. The demands of each country were recorded and the possibilities of fulfilling it from the excess production or capacity of another considered. Then such products as phosgene, chlorpicrin, and mustard gas were taken up in the same manner and finally recommendations were made to the competent authorities. Much was accomplished by these meetings, where these questions were frankly discussed. It was soon found that large stocks of gas supplies were being held by one country that were badly needed by another and in this way, to cite but one example, our gas production, which was running ahead OF our shell capacity, was utilized in supplying our Allies’ needs, considerable shipments of bulk gas being made a t really critical times. The Commission had nothing to do with financial matters or price fixing, these being left to the proper missions to arrange. When, in August 191sthe High Interallied Munitions Council was organized, the Commission for Chemical Warfare Supplies was taken into that body and became its “Chemical Committee.” In addition to all chemical warfare material, it was
7 23
assigned glycerin, asbestos, and talcum, and not only were programs of the different countries to be considered by that Committee, but the tonnage schedules of the Interallied Maritime Council for the materials handled were to be filled out as far as possible in accordance with the military requirements for periods of six months. Only two meetings of the Chemical Committee were held, one on September 2, 1918, and one the week following the armistice, to clear up questions of existing contracts, after which the Commission adjourned sirte die. The writer has felt that the series of articles on the Chemical Warfare Service in THISJOURNAL would not have been complete without a short account of the organization of these interallied bodies, which not only accomplished much on the material side but, as pointed out before, had a most beneficial effect in bringing close together chemists of the allied countries in a way that it is hoped will have lasting effects. It seemed to him worth while to call attention of chemists in general to the existence of these organizations with a hope that the work they accomplished and the spirit which animated their meetings may serve as a starting model for similar groupings in the future. NEW YORKCITY
A FERMENTATION PROCESS FOR THE PRODUCTION OF ACETONE AND ETHYL ALCOKOL1,2~* By JOHN H, NORTHROP, LAUREN H. ASFIEAND R. R . MORGAN Received June 27, 1919
Acetone was one of the substances for which the war created a greatly increased demand. I t was needed by all the Allies for the dope used on airplane wings and b y the English in addition for the manufacture of cordite. The ordinary source of acetone, the dry distillation of wood, proved quite inadequate to supply the quantities needed. It became necessary, therefore, to develop some new method for the production of acetone. Large quantities were made from calcium acetate which was in turn produced from acetic acid obtained by the oxidation of alcohol. The expense of this process, however, rendered it unpracticable. It seemed important, therefore, under these conditions, to attempt the development of a direct fermentation process for the production of acetone, inasmuch as such a method, if successfully developed, would furnish acetone in practically unlimited quantity and a t a low cost. Several fermentation processes for the production of acetone have been described and patented,4 and of these, the Fernbach processt5 has proved t o be a com1 The work described in this paper is the outcome of a suggestion of the Council for National Defense t h a t n fermentation process for the production of acetone be worked out. The laboratory work and the preliminary large scale experiments were conducted a t the chemical laboratories of the Rockefeller Institute. A second series of experiments was done a t the laboratory of Arthur D. Little, Inc., of Cambridge, Mass., under a grant from the Bureau of Aircraft Production, and the final work was carried out a t Terre Haute, Ind., a t the plant of the Commercial Solvents Corporation. The authors wish t o express their indebtedness t o the Commercial Solvents Corporation, and particularly t o Dr. Nelson B. Mayer and Mr. Robert D. Clark, for placing every facility of the plant a t Terre Haute a t their disposal. 2 Published b y permission of the Director, Chemical Warfare Service. a The process described in this paper is protected by U. S. Pat. 1,293,172, assigned t o the Rockefeller Institute for Medical Research. This patent has been dedicated to public use and is held, under these conditions, by the U. S. Patent Office. 4 Bayer and Company, D. R. P. 283,107, July 1913; D. R . P. 291,162, Jan. 1914; Brit, P a t , 14,371, June 15, 1914; Delbruck, U. S. Pat. 1,169,321; Fernbach and Strange, U. S . Pat. 1,044,368, Nov 12, 1912. 8 A process similar a t least t o the original Fernbach process has been developed in England by Dr. Weissman. It has been used successfully in this country and in Canada.
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
7 24
mercial success. It has t h e disadvantage, however, of producing twice as much butyl alcohol as acetone. This alcohol, though valuable, is one for which there is a limited demand and is therefore difficult t o dispose of when produced in large quantity. The present work iq an attempt t o develop a process which yielded largely ethyl alcohol as a by-product, with smaller amounts of propyl and butyl alcohols. The organism used is described under the name of B . acetoethylicum in a paper which is t o appear shortly in the Jowlzal of Biological Chemistry. The general characteristics of t h e organism together with the optimum conditions for its growth may be summarized as follows: TABLEI DESCRIPTION OF THE ORGANISM-Described of the Society of American Bacteriologists.
according t o descriptive chart
IX-FERMENTATION OF SUGARS, Ferments the following tion of CaCOs and sugars in 1 per cent peptone or nitrogen solution with addi-
-
(1) Vegetative cells, motile From 24 hrs. agar slant, 40' C.-Short rods 4-6 M & I X 0.20.3 p#. No chains. Ends r o u n d e d . Stain evenly with Loeffler's methylene or gentian blue violet. Gram negative.
Ferments levulose and galactose under following conditions: Medium: 1 g. KHzP04, I g. (NHa)eHPOd, 0.01 g. NaCl, 1.0 g. CaCOs, 10.0 g, levulose, per liter.
( I ) 2 per cent glucose agar slant, 24 hrs., 40° C.-Moderate, spreading, effuse, dull, translucent, no odor. Condensation water opaque. (2) Potato, 24 hrs., 40° C.-Gas bubbles all over media. Crumbles easily. No odor. 2-3 d a y s , 40' C. -Media sinks t o grayish white paste. (3) Glucose broth, 24 hrs., 40' C.-Cloudy. No odor. days--$ h i n y 2-3 mass in bottom.
-
=
For ferm e n t a t i on, PH = 6.0 to 8.0.
8.0
to 9.0, fv-VITALITY At least 6 months a t room temperature.
OF
CULTURE MI~DIA At least 1 month a t 40' C.
V-TEMPERATURE R ~ L A T I O N Spores may be boiled Optimum temperature a t least 20 min. 40' t o 43" C. VI-RESISTANT TO DRYING Formic acid
P u t in tubes and sterilized as described by Schardinger; inoculated with pure culture of the bacteria and insubated 12 days a t 40° C.
per cent Alcohol Per cent 14-16 22-23 24-25 18-20 40-43 24-26
Acetone = 8-9 per cent. Alcohol = 14-20 per cent. Starch does not ferment under these conditions,
solutions, having a reaction of pH 8.09.0, large quantities of slime are formed
FORMATION
so that the whole media becomes very viscous. U n d e r conditions of fer-
mentation small de posit of slime settles to the bottom.
It was found in the preliminary laboratory experiments already described t h a t t h e fermentation, if carried out in the usual way by inoculating a sterile mash: with a relatively small inoculating culture, required! 5 t o 6 days for completion. It was also found t h a t t h e organisms collected in a slimy mass at the bottom of the fermenting liquid, a fact which becomes more disadvantageous with the increase in the size of t h e fermenting vessel. Both these difficulties were overcome by using a fermenter filled with pieces of broken marble.' Under these conditions the process was made semicontinuous by merely draining off the fermented' liquor and adding fresh sterile mash. The organisms remain as a slimy scum on the limestones and serve t o start the succeeding fermentation. The fermentntion was complete in 40 to 60 hrs. and there seemed every reason t o suppose t h a t its course would not. be markedly influenced by the size of the fermenting vessel. It was decided, therefore, t o repeat t h e experiments on a larger scale, APPARATUS
111-OPTIMUM REACTION OF MSDIW
For growth, pH
.........
XI-SLIME
If-CULTURAL FEATURES Edge entire or un(4) Litmus milk, 24 dulate. I n t e r n a 1 hrs., 40' C.-Bottom structure, coarsely of tube white, no granular. gas, odor, acid, or (6) Sodium chloride i n clot. bouillon- Inhibiting 36 hrs., 40a C.4-5 concentration Milk red on top, rest per cent. white. (7) Nitrogen Wit h 7 2 hrs., 40' C.sugar as carbohydrale Same but coagulated; obtained from pepclot does not digest tone, proteins, or subsequently. ammonium salts. ( 5 ) Agar Plat colonies, With starch-Same 2 per cent glucose but cannot use agar, 24 hrs., 40' C. ammonium salts. -Growth slowly (8) Best media for longspreading. Round, continued growth-2 outline irregular. per cent corn in Surface smooth. media with CaCOa. Elevation-effuse.
-
X-AIR RELATION Facultative anaerobe.
I n 16 per cent sugar (2) Spores-Elliptical, form a t end of rods. Stain easily with methylene blue or gentian v i o 1 e t. 0.5-1.0 &&I in diameter.
source, 15 cc. in test tubes.
........ ......... ..........
.......... ........ ..
No. 8
ETC.
......... .........
...........
aceloethylicunt.
I-MORPHOLOGY From 24 hrs. 10 $eV cent corn mediaSame as above but sh or t occasional chains. From old (6-10 days) 10 Per cent corn media-S t a i n unevenly with deeply staining spot a t end or in center.
11,
Temperature = 37'C., Substrate 2 per cent Sugar, I Peptone, 2 per cent CaCOs. Time of Fermentation 10 Days Acetone Alcohol Acetone Per Per Per SUBSTANCE cent cent SUBSTANCE cent Galactose.. . . . . . . . 4- 5 22-24 Dextrin 6- 7 6- 7 23-24 Dextrose 9-10 Maltose Mannose 6- 7 22-23 Levulose 8-10 Xylose 4- 5 Raffinose.......... 8-10 22-23 d-Arabinose 6- 7 12-16 Glycerin Sucrose 8- 9 Calcium lactate.. Starch.. .......... 8LiO 2bLi4
SOURC~--FCO old ~ potatoes obtained from Berkshire Co., Mass., July 1, 1917. ~ROPOSED NAME-BaCZ'UUS
Vol.
VII-PRODUCTS OF REACTION Ethyl, propyl, butyl alcohol VIII-PATHOGENICITY Non-pathogenic to mice
Acetone
The apparatus used was of copper, tin-lined, and consisted of two closed vessels of about I O gals. capacity each. One, which was used as a sterilizer o r cooker, was fitted with stirring apparatus and an interior coil which was connected both t o the steam and cold water system. The fermenter itself was a similar vessel, but without t h e steam coil, and was filled with broken lumps of limestone about the size of an egg. It was connected t o the cooker by means of a 3/4 in. pipe. The fermenter and' connecting pipe were both connected with the steam line so t h a t they could be sterilized. 1 It was found later that any inert material could be used, provided the fresh mash was made slightly alkaline (9H 8.0 to 9.0), so as t o maintain the reaction a t a p H of 6.0 to 7.0 during the course of the fermentation.
T H E JOURNAL OF INDUSTRIAL A N D ENGINEERING CHEMISTRY
Aug., 1919
MASH
A solution of beet molasses1 was found the material most conveniently handled in the large size apparatus. The molasses used contained I . 0 5 g of sugar (determined as dextrose by reduction after hydrolysis) per cc. For fermentation i t was diluted t o 1 5 times its volume with water. This mash therefore contained 7 0 mg. total sugar per cc. EXAMPLE O F A N EXPERIMENT
The fermenter and connecting pipe were heated under lbs. steam pressure for 6 hrs. on three successive days and then allowed t o cool t o 40°, air being admitted through a cotton filter. 0.5 gal. of beet molasses was diluted t o 7.5 gals. with water and heated in the cooker under 15 lbs. pressure for 4 hrs. The mash was then cooled a t 40' (by running water through the coil), forced into the fermenter with air pressure, and inoculated with I gal. of fermenting mash. This had been sterilized in a large Pasteur flask and inoculated 24 hrs. previously with 5 agar slants of t h e organism. The temperature of the room in which the apparatus was placed was maintained a t 40' C. Samples were withdrawn and analyzed a t intervals. The acetone and alcohol were determined by the method described in t h e paper on the laboratory experiments. T h e reaction (pH) of t h e n p s h was determined roughly by brom-cresol-purple, phenol red, or phenolphthalein. The results of the analyses are shown in Table 11. IO
TABLEI1
--A-TON-
-.
After Inoculation
Hrs. 0
1
48 50 24 50 24 52 24
48 56 72
As per -ALCOHOL-cent of Per As Original CC. of per cent Sugar Solution of Sugar Percent Mg. Percent
Per Sugar per cc. of cc. of Solution Solution Mg. Mg. 9H 0.07 0~.~ .1 70 8.5-9.0 0.24 0.3 6.5 2.0 3.0 .. 6.0 i:4 1i:o 11 5.3 6.0 3.7 Old mash run out and 5 pals. fresh mash run in 0.4 0.5 65 8.0 5.4 7.7 10 6.0 5.6 8.0 14:s 20:O 8 6.0 Old mash run out and 5 gals. fresh sterile mash run in 2.3 3.3 47 8.5 5.9 8.4 i4:g 2i:3 3 6.0 Old mash run out and 5 gals. fresh sterile mash run in 2.8 4.0 40 8.3 14:O 2610 4 6.0 5.8 8.3 Old mash run out and 5 gals. fresh mash run in 3.0 8.1 5.0 *.
.. ..
.. ..
..
5.9 6.0
-
..
... ...
.. ..
..
8.5
1i:2
2i:7
...
..
.. .. ..
3
... ...
6.0
It will be seen t h a t , after the first refilling of the tank the fermentations were complete in 50 t o 60 hrs. with a yield of 8 t o 8 . 5 per cent of the sugar as acetone and 20 t o 21 per cent as alcohol. Calculated as volume per cent of the original molasses, the acetone is g to I O , and the alcohol 2 2 t o 23 per cent of the original volume. The alcohol was identified, as described in the paper on the laboratory eiperiments, as ethyl alcohol containing probably some propyl and some butyl. The hydrogen ion concentration varies from about p H 8 . o a t the beginning t o p H 6 . o a t the end. The optimum condition for fermentation is within this range. 1 Information had been received a t this time from the Department of Agriculture and also from the War Industries Board that large quantities of this molasses were available for fermentation; it was found later, however, that there was actually very little of the substance on the market.
7 2.5
The fermented mash from the foregoing experiments was distilled and finally fractionated in glass, yielding about 7 5 per cent of the calculated amount of acetone and alcohol in the form of the pure substances. As no special precaution was taken t o make the fractionation strictly quantitative, the yield from the distillation agrees fairly well with the quantity found by analysis. The experiments described above were repeated by Lieut. Ashe a t the laboratory of Arthur D. Little, Inc., Cambridge, on a larger scale. I n these experiments the fermenter held 160 t o 175 gals. The fermentation was slightly slower t h a n in the previous trials but gave a higher yield. It had been found in t h e meantime t h a t if t h e mash were brought t o a pH of 8 . 5 t o 9 . 5 by the addition of lime before fermentation the limestone in the fermenter could be replaced by brush or any similar inert material. The work was therefore repeated in Terre Haute with a tank holding about 800 gals. and filled with brush instead of limestone chips. The fermentation took place in the same way and with the same yields as in the experiments described. I n all the foregoing fermentations the principal difficulty encountered was the prevention of contamination by foreign organisms which destroyed the acetone already formed, or interfered in other respects with the fermentation. T h e danger of contamination was particularly great when the old mash was drawn off. It was thought, therefore, t h a t the process would be much easier t o control as well as more rapid if the mash could b e drawn off and run in in such a way as t o avoid emptying the tank. This could be done by running in the fresh mash gently a t the bottom and allowing the fermented mash t o flow off a t the top. I n this way the fermenter could be always kept filled and under pressure and the danger of contamination greatly lessened. It was found impossible t o test this method in the laboratory as the fresh and fermented mash mixed too much in a small vessel. It was decided, therefore, t o install an apparatus of about 1000 gals. capacity. APPARATUS
A steel tank 4 2 in. in diameter and 1 2 f t . high was set up and connected with the cooker and cooling coil as shown in Fig. I . The various steam
Cooker
FIQ. 1
connections are apparent. It will be seen t h a t the outlet of the tank was sealed off with steam which was always kept turned on slightly (Valve D). The tank
7 26
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
was filled with broken corn cobs’ and had four transverse perforated plates in order t o prevent mixing. MASH
The following experiments were made, using poor grade cane molasses (“black strap”) such as is used for fermentation. It contained 760 to 780 mg. of total sugar (as dextrose) per cc. It was found t o be slightly acid in reaction, so t h a t it was necessary t o use considerable lime to bring it t o the proper degree of acidity. The sterilizing was complicated by the fact t h a t the cooler was on a long (nearly 1000 f t . ) steam line and therefore received very wet steam, so t h a t the volume of mash increased greatly during sterilizing. This made i t necessary t o work with very dilute mashes since if high concentrations of molasses were used, so as t o finish with the correct concentration, too much sugar was lost by caramelizing in t h e Erst part of the heating. Air-slaked lime was used to neutralize t h e molasses at the rate of 5 lbs. of lime per 5 gals. of molasses. Owing t o the arrangement of the apparatus it was necessary to add this lime before sterilizing, although it was realized t h a t this was not advisable. Nearly twice as much lime is needed if this is done and more sugar i s destroyed. The lime should be pumped into the sterile mash after cooling.
Vol.
11, No.
8
MASH
5 gals. of molasses, I 2 0 gals. of water, and 5 lbs. of airslaked lime were then sterilized under 1 5 lbs. pressure for 3 hrs., run through t h e cooling coil by steam pressure, and cooled t o about 30’ C. before entering the hot fermenter. The latter was filled t o Stopcock I ; and four 2-1. cultures run in through t h e inoculating cock and washed into t h e fermenter. These cultures had been inoculated from agar slants of B. ncetoethylicum, and incubated for 24 hrs. The mash, owing t o dilution while sterilizing, contained only about 9 . 5 mg. sugar per cc., whereas i t was possible t o ferment a mash containing more than three times as much sugar. The pipe line connecting the cooler and fermenter was kept under j to I O lbs. steam pressure when not in use and care was taken t o prevent access of air t o any part of the system. The outflow of gas from t h e fermentation was regulated so as t o maintain 2 t o j lbs. pressure per sq. in. in t h e tank. This greatly reduces the danger of contamination. Percent of 8ugbT as acetone
INOCULATION
This molasses was difficult t o bring into fermentation and the difficulty was increased by the fact t h a t no apparatus was available for “building up” a large inoculating culture. A series of six Pasteur flasks, each of 2-1. capacity, was therefore used, giving an inoculation of about z gals. This was not sufficient. t o start fermentation in t h e entire 400 gals. of mash, so t h a t a t first attempts were made t o start 40 to 50 gals. of mash fermenting in the bottom of the tank and then to add t h e remainder of the mash slowly. It was not found possible t o prevent contamination by this method, a butyric acid organism being the one which caused the most trouble. It was found possible, however, t o keep the top of the tank (above Stopcock I) under low steam pressure while the culture was growing in t h e lowest part of the tank. Fresh mash was then added gradually until the entire tank was filled. I n this way all possibility of contamination was avoided. The following fermentation was carried out in this manner: STERILIZATION
The fermenter was sterilized I O hrs. a day for 8 days, under 2 0 lbs. steam pressure and then drained through the bottom cock. Cock I was now opened, all t h e others closed. and the steam valve a t D opened slightly so as t o allow a little steam t o blow through the tank and out a t Cock I , Cocks A and B being closed. Corn cobs were used since they were the most readily available material and since they worked very well in laboratory experiments. They were found t o be unsuited for use in a large tank as they gradually settled down and so greatly reduced the volume of liquid which the tank held Coke or beech shavings, such as are used i n vinegar towers, would probably be much more suitable. 1
FIG.2
After the t a n k had been filled the temperature was kept a t about 40’ C. by allowing a stream of water a t approximately t h a t temperature t o flow over it. TABLEI11
-ACETONE-
. . . . . . . . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ......... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .. .. .. .. .. ...... ................... ......................
23 100 9.4 56 1.4 0 . 4 0.35 0 . 4 57 75 9 . 0 82 4 . 3 2 . 8 3 . 3 2.4 1 . 2 105 5.0 5.2 3.5 1.3 106 75 10.0 1.3 1.7 1 . 9 2.4 2!.4 3 . 6 107 6 . 6 6.2 3 . 6 4.2 4 . 0 4 . 2 124 7.4 6.6 4 . 5 4 . 0 41.0 4 . 4 . . . 130 131 75 9 . 6 ........ ........ 1 . 7 2 . 2 3.2 4:s i.0 5 . 0 5 . 0 131.5 7.4 7.6 5.6 5.2 5 . 4 5 . 4 5.4 139 9.2 9 . 0 7.4 6 . 2 6 . 2 6 . 0 6 . 2 147 152 10.0 8 . 6 7.2 6 . 4 €).L 3 . 8 0 . u 152.5 100 9 . 5 . . . . . . . . 1.8 2.0 2.6 3 . 6 4.0 5 . 8 5.4 153 164 . . . . . . . . 9 . 0 8 . 0 8 . 8 7.2 5 .. U. .6 .. 4. .6 .. 3. 164.5 50 9 . 8 175 . . . . . . . . 8.8 9 . 4 1 0 . 4 7 . 4 i . 0 7 . 0 7.0 . . . . . . . . . . . . . . . . . . .. . . . . 175.5 50 9.7 187 . . . . . . . 9 . 6 9.2 9 . 2 8 . 0 8 . 0 8 .O 8.0 188 50 9 . 6 5 . . . . . . . . . . . . . . . . . . . . . . . 10.6 8 . 9 8 . 9 9 . 1 910 9 . 3 9 . 2 199 199.5 50 10.0 . . . . . . . . . . . . . . . . . . . . . . . . 50 9.7 ........................ 211
..................................... ................ ................ ............. 50 4 . 3 4 . 3 .... .. .. ..... .. .. . ....... .......... . . . . . . . . . . . . . . . . . . . . . . . io0 6 . 0 6 . 0 ....
........ ........ ........ .... .. .. .. .. ........ .. .. .. .. .. .. .. ..
...............
. . . . . . . . . ..... ...
6:4 6:4 .... ............. 50 7.0 7 . 0 . . . . ...
. 50
. . . . . .50. . .8:O gib 2O:O ......... 50 9 . 0 9 . 0 22.3 50 8 . 9 8 . 9 22.4
AW., 1919
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 CHEMISTRY
I t will be seen from Table 111 and Fig. 2 t h a t the concentration of acetone gradually increased in the liquid in the upper part of t h e tank (Stopcocks j, 6, 7 ) , until i t reached about 0.9 mg. per cc., corresponding t o 8 t o g per cent by weight of the sugar originally present. I t then remained constant a t this point. These changes are shown graphically in Fig. 2. The analysis of the lower part shows a decided drop immediately after every additional charge of mash was run in. The concentration of acetone then increases quite rapidly until i t reaches 9 t o I O mg. per I O cc. This shows t h a t there is no excessive mixing under these conditions even in a t a n k of the size used in this experiment. It is possible therefore t o keep such a tank in continuous fermentation by adding
727
fresh mash a t the bottom and allowing the fermented mash t o run off a t the top. T h e larger and higher the tank the more rapidly the mash could be run through. The reaction of the mash varied from $H 8 . 0 to 9.0 in the fresh mash t o p H 6 . 0 t o 7 . 0 in the spent mash. It was therefore always near the optimum for fermentation. S UMM AR Y
A brief description has been given of a n organism which produces acetone and ethyl alcohol. A method for conducting a continuous fermentation with molasses has been suggested and a n experimental fermentation described. ROCKEFELLER INSTITUTE FOR MEDICAL RESEARCH NEWYORKCITY
-.
EFFICIENCY A N D PRODUCTIVITY OF W A G E A N D SALARY EARNERS IN THE CHEMICAL INDUSTRIES AN ATTEMPT T O OBTAIN AN ANSWER I
By 0.P. HOPKINS. Washington, D.C.
I n the discussion of national aid t o our industries which will sooner or later become an active and vital question in the national development of all our domestic industries for the purpose of making our national industrial fabric, as a whole, as self-contained, selfsupporting, and self-developing as conditions will permit, exact knowledge concerning fundamental questions of markets, production, efficiency of production, and productivity, both domestic absolute values and also relative values for the leading competitive nationals, will be of paramount importance. To this our chemical industries are no exception. I n furtherance of this independence, the Bureau of Foreign and Domestic Commerce has greatly aided our chemical industries by compiling and publishing the Norton Dye Census and the Pickrell Chemicals Census. Our SOCIETY, through its standing ex-oficio Committee on Import Statistics, is endeavoring still further t o reduce t o quite simple terms the exact kind and character of our dependence concerning raw or partly manufactured materials as disclosed by the Pickrell Census a n d in this the Geological Survey and the Department of Agriculture are further aiding t o reduce this dependence not only t o simpler terms but are indicating, where possible, remedies for those dependencies or workable domestic substitutes therefor. I n determining competitive ability, knowledge of markets, accessibility t o markets, and control of supplies of raw or partly finished materials are only some of the factors involved. Amount of product or of value added by manufacture per dollar expended for service and per individual engaged a n d their relative distribution over wage earners and salary earners, expressed in “ e x c l u s i v e averages,” are of directive but not controlling importance. Up t o the present little, if any, information is available on these points for our chemical industries. This may very well be because suitable fundamental information is not available. However, our Census of Manufactures offers some data capable of giving
some light on these important questions for our entire industrial activities including, of course, our chemical and allied industries. THIS J O U R N A L , believing t h a t such information, even though i t be not rigidly exact nor of t h a t ultimate refinement necessary t o a definitive and conclusively binding, universal, and specific answer, would nevertheless be directionally and relatively true and t o t h a t extent helpful, has enlisted the aid of Mr. 0. P. Hopkins in a n effort t o throw as much light on these questions as the d a t a available for the United States, England, France, Germany, and Japan permit. T o this end Mr. Hopkins has undertaken the statistical article presented in this number, in an effort t o supply the material in a form from which an answer may be deduced t o questions relating t o productivity of labor and the like units and of expenditures for labor and the like. Should the result of this work be disappointing in this respect, i t will have served its purpose eminently if it will have shown conclusively the importance of information of this kind, the need for proper fundamental information, and will have induced the proper officials of our Government t o collect the fundamental data essential t o a correct, complete, precise, and comprehensive answer t o the questions whose answering is the ultimate object of this e f f o r t . - [ E ~ ~ ~ ~ ~ . ] This article is presented t o the readers of THIS J O U R N A L for the purpose of establishing in their minds certain facts as t o the standing of the chemical and allied industries in t h e industrial community, and also for the purpose of showing. so far as is possible, how the American chemical and allied industries compare, in these certain respects, with similar industries in England, France, Germany, and Japan. The chemical industries are contrasted with other American industries on the basis of value of annual product per wage earner, per salary earner, and per service unit (or per employee), carried t o the nearest dollar; and also per wage dollar, per salary dollar,
