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L. A. Rogers' collected samples above and below a source of pollution on a stream. Above t h e pollution, t h e greater percentage of t h e organisms of t h e colon-aerogenes group were soil strains, while below t h e pollution, t h e greater percentage were fecal strains. The variation i n per cent of soil a n d fecal strains of organisms of t h e colon-aerogenes group from surface water supplies is shown graphically in t h e accompanying diagram. EFFECTOF DROUTHON THE AVERAGENUMBER O F ORGANISMS OF THE COLON-AEROGENES GROUPPER Cc. IN SURFACEWATER O N THE AVERAGE NUMBER O F ORGANISMS GROWNON AGARAT 37' IN 24 HOURSA N D THE PER CENT OF FECAL STRAINS
TABLEIV-THE
Per cent Reduction in Total Count of CITY Organisms Cherryvale.. 88 89 Independence.. Coffeyville.. . 95 82 Humboldt.. . . Chanute.. . , . . . . 76 AVERAGE.. .. .. . 90.7
.... . . .. .. .. . .
Per cent Reduction in hTo.of Organism of Colon-Aerogenes Group per Cc. 6.7 7.7 2.2 19.0 0.31 7.2 ~~
Per cent Increase in N o . of Fecal Strains -1.6 75.1 39.1 36.2 6.5 24.39
Vol. 9, No. 7
The samples ranged from t h e most expensive t o t h e cheapest grades on t h e market and included fortyfour different brands from twenty-six concerns. T h e samples were obtained on t h e open market and we have no knowledge of t h e method of preparation. All cans were in good condition and all held a vacuum, no swelled ends being found. All samples were offered for sale and were in a merchantable condition. The fish was firm and of good flavor and odor in all cases. I n some of t h e cheaper brands t h e meat was somewhat dry, light-colored a n d contained rather small amounts of oil, b u t these were not sold as a highgrade product. T h e following commercial grades were examined: Red and GRADE: Sockeye Red Alaska Samples.. . , 8 24
..
Chinook 2
Cohoe 2
Pink 10
Chum 6
CONCLUSIONS
BACTERIOLOGICAL EXAMINATION
I-There seems t o be no difference between soil and fecal strains of organisms of t h e colon-aerogenes group from surface water supplies in their resistance t o treatment, nor is there a difference between cultures of t h e four principal groups of MacConkey, isolated from surface water supplies in their resistance t o treatment. 2-There is a correlation between t h e increase in t h e fecal strains of organisms of t h e colon-aerogenes group during dry weather a n d t h e sanitary survey. T h e writers wish t o express their appreciation for t h e assistance and criticism of C. C. Young, Director of t h e Water and Sewage Laboratory, a n d C. A. Haskins, State Sanitary Engiaeer. The Kansas State Board of Health helped materially in t h e survey.
The tops of .the cans were carefully cleaned a n d covered with a j per cent solution of carbolic acid for about I O minutes. This was then poured off a n d denatured alcohol added for about j minutes. The excess of alcohol was removed and t h e remainder burned. T h e t o p was then thoroughly flamed with a Bunsen burner flame. T h e can was tilted several times, flamed again a n d opened with a previously boiled and flamed can opener, with as little agitation as possible. The floors, table t o p a n d hands of t h e operator were carefully washed with carbolic acid solution before t h e operation began. Standard meat juice agar plates, dextrose fermentation tubes, bile lactose fermentation tubes, deep agar shakes, milk with a n d without calcium carbonate added, Endo agar plates a n d t h e condensation water on agar slants were inoculated. The material for these inoculations was taken from as near t h e bottom of t h e can as possible. T o t h e Petri dishes were added 2 cc., I cc. a n d 0 .I cc. of salmon liquor, about 0.5 cc. was added t o t h e milk and fermentation tubes, a large loopful was added t o t h e deep agar and t o t h e condensation water of t h e agar slants. A p a r t of t h e milk was heated t o 8 j " C. for IO minutes a n d cooled quickly in cold water. The agar shakes were also cooled quickly by plunging t h e m into cold water as soon as inoculated. A large loopful of material was smeared upon a clean slide, fixed in absolute alcohol for 15 minutes a n d stained in dilute methylene blue for 30 min. All cultures were incubated at 37' C. for 48 hours a n d careful examination made. They were placed a t room temperature for j days a n d again examined. As a check upon t h e methods, t h e increase in temperature of t h e contents of t h e can due t o t h e flaming was noted b u t i t was not influenced. The media was checked against B . typhosus; B . enteritides; B. coli c o m m u n i s ; B . p a r a t y p h o s u s , A and B ; B . tetani; B. botulinus; B . arithracis s y m p t o m a t i c i ; and three cultures of B. U'elchii, all of which grew readily. As a check on t h e ability of organisms t o grow in t h e salmon, thirteen samples taken a t random were placed in test-tubes a n d inoculated with t h e first five
WATERA N D SEWAGELABORATORY STATE BOARD O F HEALTH,LAWRENCE, KAESAS
THE EXAMINATION OF CANNED SALMON FOR BACTERIA AND TIN* By L. D . BUSHNELLAND C. A. A. UTT Received April 18, 1917 INTRODUCTION
Reports from t h e Division of Vital Statistics of t h e Kansas State Board of Health show a number of deaths in this state supposed t o have been due t o t h e eating of canned salmon. D a t a other t h a n t h a t are lacking. Mr. L. A. Congdon, Assistant Chief Food and Drug Inspector of t h e Kansas State Board of Health, suggested t o us, through Dr. J. T. Willard, chief of t h e food laboratory of t h e Kansas State Agricultural College, t h e bacteriological examination of samples of canned salmon, with t h e view particularly of noting t h e presence of paratyphoid-like organisms. T h e s t a t e inspectors h a d sent in fifty-two samples of t h e various brands t o t h e food laboratory for examination for tin. These were also used for bacteriological examination. 1 "The Viability of Different Types of the Colon-Group in Water," L. A. Rogers. J. of Bact. (Abstract), 1, 83. 2 Published b y permission of W. M. Jardine, Dean of the Exp. Station, and J. T . Willard, Chief of the Food Laboratory, Kansas State Agricultural College, and S. J. Crumbine, Sec. Kansas State Board of Health.
July, 1917
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
organisms mentioned above. These were incubated a t 37’ C. for 48 hrs. a n d examined microscopically for increase in number of organisms. I n every case all grew very readily. The results obtained from t h e bacteriological investigations were entirely negative. I n a very few cases a mold developed on t h e plates a n d in one case a spore-forming organism developed. I n no case did we find growth in fermentation tubes or deep agar or milk cultures. Stained slides were made from fermentation tubes in many cases, b u t no organisms were seen. No organisms were ever noted upon slides made directly from t h e cans. About 50 g. of this material from I O different brands were fed t o white rats. They a t e most of this in two days; after t h a t t h e y were kept for three weeks on ordinary feed, but failed t o develop symptoms of a n y sort. EXAMINATION FOR TIN
Twenty of t h e above samples were analyzed for their tin content. These included t h e best and cheapest brands on t h e market a n d were picked a t random without a n y reference to their quality. Tin determinations were made according t o Journal of OJicial Association of Agricultural Chemirts, Vol. 11, No. 2, page 173. All tin determinations ran below jo mg. per kilogram, showing t h e y were well below t h e tolerance of 300 mg. per kilogram. C 0 N C LU S I 0 l iS
Canned salmon as found on t h e market in this state is sterile. It does not contain organisms of B . paratyphoid type, a n d does not contain aerobic or anaerobic spore formers. This is t o be expected if t h e packers process their goods according t o advertising material which they publish. I n one case t h e y claim t o heat t h e cans t o 220’ F. for 50 mins., followed by a heating t o 240’ F. for 60 mins. on a second day. This is necessary t o protect t h e packers against loss of goods after i t has been p u t on t h e market. From t h e fact t h a t this material will readily support t h e growth of pathogenic a n d other microorganisms, great care should be exercised in handling it after removal from t h e can. KANSASSTATEAGRICULTURAL COLLEGE MANHATT.4N KAXSAS
THE INDUSTRIAL CHEMISTRY OF CHICLE AND CHEWING GUM1 By
FREDERIC DANNERTH
The official estimate of chicle imported and converted in t h e United States in 1916 approximated 7,347,000 lbs., equivalent t o a t least 30,000,000 lbs. of chewing gum. An industry which has assumed these proportions may well be said t o exert a n influence on our national life. The retail selling price of t h e finished article is at t h e rate of S I . 30 per lb., from m hich some idea of t h e financial strength of t h e industry may be obtained. 1 Presented a t the 54th Meeting of the American Chemical Society. Kansas City, April 10 to 14, 1917.
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I n view of this i t has become necessary t o establish standard methods for t h e purchase of the Crude Block Chicle. As i t arrives a t t h e port of New York or New Orleans i t contains a considerable amount of moisture-usually about 40 per cent. The factors which influence t h e purchaser may be summarized as follows: (I)-The moisture t h e gum is estimated t o contain. (a)-The shrinkage when cleaned (dirt a n d bark). (3)-The chewing quality of t h e clean purified chicle. (4)-The color of t h e crude chicle. MOISTURE
The amount of moisture contained in crude chicle was until very recently ascertained in t h e course of factory operations. For example, a Ioo-lb. lot was chopped up into ‘/*-in. crumbs a n d dried in a hot air chamber. T h e loss of weight was recorded as moisture. A somewhat better idea of t h e value of t h e chicle can be obtained by proximate analysis. T h u s one sample of Yucatan chicle when examined in t h e laboratory showed: Per cent Acetone-soluble matter (resins), . . . . . . . . . . . . . . . . 40 .O Gutta (and carbohydrates). 17.4 Proteins.. ................. 0 . 6
.
Per cent
. . . . . . 35.0 2.3 ........ 4 . 7
Sand and foreign matter. Water.. ..................... Mineral matter (ash)..
Obviously, if this chicle costs $ 0 . 5 5 per lb., crude, its value is $0.877 per lb. after drying and cleaning. I n other words, IOO lbs. of crude chicle in this case yielded 62. 7 lbs. of dried and cleaned chicle. sAawL1Kc-h sampling crude chicle after i t has arrived a t t h e factory a I-lb. sample is cut from a block. This is cut up into ‘/*-in. crumbs just as rapidly as possible. The crumbs are transferred t o a “Lightning Jar” provided with a glass lid and rubber gasket. The jar should be not more t h a n two-thirds full, leaving room for a thorough mixing by shaking t h e contents, a n d should be kept in a cool place t o prevent caking. T h e large amount of moisture usually present in crude chicle makes it imperative t o handle t h e sample rapidly. Wet chicle cannot be stored in sealed jars for more t h a n one week as molds grow rapidly, especially if t h e jars are kept in t h e dark. M E T H O D I-A weighed portion of crude chicle (about 5 g.) is dried in a well-ventilated air b a t h for 5 hrs. a t a temperature not above 50’ C. As a container for t h e sample, a glass dish 2 or 3 in. in diameter with a ground glass lid is used. If t h e temperature in t h e oven rises, fusion will occur a n d evaporation of t h e water will be retarded. If t h e oven is poorly ventilated t h e drying will take longer. It is complete when two consecutive weighings vary not more t h a n 0 . 5 per cent. M E T H O D 11-The moisture in crude chicle may be determined simultaneously with t h e determination of resins. Boiling acetone will remove resins a n d water from t h e sample by extraction. The extract in t h e flask is dried at 105’ C. a n d t h e residue in t h e thimble is dried in a similar manner. The sum of these weights subtracted from t h e weight of t h e
