T H E , J O U R N A L OF I N D U S T R I A L A N D ENGTNEERING C H E M I S T R Y
? 40
7 . 3 sec., while a sligl-ltly greater influence is shown by contamination ’ with 2 per cent of mineral matter. T h e combined effect of mineral matter and soda solution is found slightly higher than t h a t o€ t h e mineral matter alone, but not quite the sum of both. There seeins t o be some selective separation of bitumen as shown under Consistency Tests 4 and 5 , which, however, will be reduced some under t h e application of the method as i t is aimed t o extract all of t h e bitumen, not half; when t h e extraction is completed any bitumen adhering t o t h e mineral aggregate would b e but a small percentage. By taking an average of Tests 4 and 5 (consistency), 4 2 . 8 , and comparing i t with Test 3 a comparison is obtained of t h e accuracy of the test, which i n this instance was 5 . 5 sec., which seems reasonably close when it is seen t h a t t h e float test itself under these conditions gives a variation of 4 sec. The “Insoluble i n Benzene” tests clearly demons t r a t e t h a t the free carbon content of t h e bitumen is not altered t o any appreciable extent by t h e application of the method. T h e centrifuge method for the removal of t h e soda solution was adopted because of its ease of application. With t h e regular method of dehydration1 there was a very great tendency t o foam, and a possible loss of lighter constituents.
siderable study. Berthelot and Gandechon,l Kailau,2 Thiele,3 and Lesure4 have demonstrated t h e effect of ultraviolet rays in causing polymerization or decomposition of chemical compounds. Ostromisslenski5 showed t h a t vinyl bromide can be polymerized b y ultraviolet light in a few hours t o cauprene bromide. Similarly, Pribram a n d Franke6 found t h a t freshly distilled formaldehyde being exposed t o ultraviolet rays for some time contains a substance identified as glycol-aldehyde. Studies by Buchta? show t h a t light prevents t h e germination of cells. He also finds t h a t yeast cells exposed t o ultraviolet light for I O sec. d o ‘ n o t germinate a n d exposure for 3 min. kills t h e cell. Stiner a n d Abelin8 found hemolytic amboceptors, diluted I : 100, t o be destroyed in I O min. llrvnres Fungus
Oidiwm olbirnnr Ch. Robin Pororacrharomyies A rhjordii Anderson Pororacchoronyies Thomnsii Anderson Socchnromyier albur Sotchoramyces anrmolour Hansen Sorrharomycer of Binot Sncch+romycer of Curtis Saccharomyces cereniriae Hansen Sarrhoromyccr rlliproidrur Hansen Sacrharomycrr hominir Busse Saccharomyces morrinnus Schizorairhnromycer Pombe Linder Torula m o i i o ~ ( ~ Torula humiiola Daczewska lVillia brlgiia Linder Zygosarchnroinyeer bisporur Anderson
OF SURVIVAL OF EACH ORGANISM AFTER EXPOSURE TO U L T R A V I O L E T L I G H T
FIG. TI TIME
Likewise Hartoch, Schurmann and Stinerg found diphtheria toxin t o be weakened by exposure t o t h e rays. Agulhon’O and Chaulpeckyl* studied t h e action of ultraviolet rays on enzymes which were shown t o be rendered inactive. Amylase a n d invertin are exceedingly sensitive t o them, and albumin is coagulated by their action. Further, Chamberlain a n d Vedder12 find amebae egisting in water supplies, whether motile or encysted, very easily killed on comparatively short exposure t o t h e rays. Von Recklinghausen13 gives considerable d a t a on t h e bactericidal activity of ultraviolet light together with its adaptability i n t h e purification of water. Comfit. rend., 153 (1911), 383. Monatsh., 84, 1209. 8 2 angew. Chem., 22 (1909), 2472. 4 J . #harm. chimie, [71 1 (1910). 569. 5 Chem.-Ztg , 36 (1912), 415. 6 Monatsh., 3S, 415. 7 Centr. Bakt. Parasitenk., I I Abt., 41 (1914), 340. 8 2. Immunitllt , 20 (1914), 598. 9 I b i d . , 2 1 (1914), 643. 10 Ann. inst. Pasteur, 26 (1912), 38. 11 Zenlr. Biochem. B z o p h y s , 14 (1912), 927. l a Philippine J . Sci , 6B (1911), 383. 18 J . Frank. Inst., 1914, 681; J . A m . Water Works A s s o c , 1 (1914), 565 1 2
THE ACTION OF ULTRAVIOLET LJGHT ON THE YEASTLIKE FUNGI-I By Bertram Feuer and F. W. Tanner STATE WATRRSURVEY DIVISION,
U R B A N A , ILLINOIS
Received March 2G, 1920
T h e effect of light on both a variety of microbial organisms and chemical reactions has received conI
Test B3.
io
Champagne yeaat c ~ ~ p i o ( o ~ogregalus cm Anderson crypioiarrur globralur Anderson Cryptrcocrur Ludwigii C,ypcoiomur ueirucosur Anderson Endomycer albicanr Monile candida Bon Mycoderma iaclir .Mycoderma monosa Avderson .Mycoderma ruforn
CONCLUSIONS
While t h e above tests were not as elaborate as desired, they indicate t h a t t h e method would prove sufficiently accurate for t h e purpose €or which i t was designed. I t is more rapid t h a n many other methods, a n d t h e t a r bitumen is separated from its mineral aggregate in substantially its true state as existing i n t h e mixture. The increase in consistency of t h e extracted bitumen is due largely t o contamination and not t o loss of constituents which with proper care can be reduced t o a minimum; althdugh there does seem t o be some slight solvent action of t h e soda solution as evidenced by its change t o a reddish brown solution. Such satisfactory results were obtained by t h e application of this method t o t h e extraction of t a r bitumens, t h a t there is no doubt in t h e authors’ minds but t h a t i t would prove equally well adapted t o t h e extraction of asphaltic binders from their mineral aggregate, perhaps not exactly as used here, b u t with some slight modification of t h e solution, dependent upon t h e character of t h e asphaltic material. This, of course, would require some further work which was not undertaken a t this time.
Vol. 12, NO. 8
Aug.,
I920
T H E J O U R N A L O F I N D U S T R I A L A N D ENGIiVEERING C H E M I S T R Y
As shown by the foregoing, ultraviolet rays have received extensive application in a variety of ways and considerable data is now available from these investigations. T o add t o t h e present state of knowledge of t h e subject this work was undertaken in order t o get a preliminary idea of t h e length of time necessary for t h e survival of a variety of yeast-like fungi upon exposure t o t h e ultraviolet rays. Kny and Lohmanl are t h e only investigators who have studied the effect of light on yeast cells, but their interest was mainly in t h e matter of germination. Further, they did not investigate t h e germicidal effect of t h e ultraviolet light on t h e types of organisms taken up here. A variety of thirty (old) cultures of yeasts listed in t h e appended table, Fig. I , were used for this investigation. The technique employed was primarily as follows: A water suspension of t h e organism was made by taking a standard loop full of t h e growth from a dextrose agar slant and distributing it in a tube containing 9 cc. of sterile water. I n t u r n these 9 cc. suspensions were placed in small-sized Petri dishes, placed in t h e position indicated in t h e accompanying sketch, Fig. 2 , and exposed t o t h e action of t h e rays.
74=
samples, and t o keep all conditions uniform throughout all the experiments. Blanks were .used in all cases t o check in each experiment. The results obtained are presented diagrammatically in Fig. I . The vertical lines indicate intervals of one minute. The horizontal line drawn for each organism shows t h e length of time t h e organism survived. Twenty-three out of 30 organisms were killed before one minute elapsed, two survived one minute, one survived three minutes, one four minutes, two seven minutes, and one ten minutes. This shows t h a t t h e majority of t h e yeast-like fungi are not any more resistant t o ultraviolet light t h a n t h e ordinary water bacteria. CONCLUSIONS
From the d a t a obtained it is evident t h a t yeast cells are not very resistant t o ultraviolet light. Possibilities are seen for the use of ultraviolet light in controlling t h e development of yeast cells in t h e industries. Further work is planned t o obtain quantitative d a t a and study the effects of t h e light on the cells suspended. in a variety of media. BIBLIOGRAPHY
,
I-Bruge, Fischer and Weil, A m J P h y c z o l , 40 (1916), 426. 2-Burge a n d Niell, A m J . P h y s i o l , 38 (1915), 399 3-Hertel, 2. allgem. Physrol., Bd 4 (1905); Bd 5 (1905) 4-Houghton and Davis, A m . J Pub Health, 4 (1914), 231 Sztz Akad TV~SS., Wien, I Abt., 120, (1911). 5-Kluyver, 6-Lohmann (Inaugural Dissertation), Rostock, 1896. 7-Lubimenko u Frolow-Bagreiew, Compt. r e n d , 184 (1912). 226 8-Oker-Blom, Z Hyg., 74 (1913), 197.
SOME ANOMALIES I N T H E SOLIDIFICATION POINT OF TRISTEARIN] By Ben H. Nicolet MELGON INSTITUTS OF INDUSTRIAL RESEARCH, UNIVERSITY OF PITTSBURGH, PA. Received October 27, 1919
FIG.2-APPARATUS
USED
IN
DETERMINING TIMG OF
SURVIVAL
The source of ultraviolet light used was from a R. U. V. quartz mercury vapor lamp operating on I I O volts. The suspension in an uncovered Petri dish was placed directly under the lamp, a t a distance of 2 5 cm. By means of a thermometer placed beside t h e dish during t h e experiment t h e temperature was noted t o vary between 30' and 40' C. At intervals of one minute until I O min. were reached and then a t intervals of j min. one loop full of t h e suspension was removed and used t o inoculate a dextrose agar slant which in turn was incubated at 37' C. for a period of 3 days. The presence or absence of growth after this period of incubation determined whether or not t h e cells were killed. Precautions were taken t o have t h e suspension as homogeneous as possible, t o secure representative 1
Bev. bolan. Ges., No. 3, 2 (1884).
PITTSBVRGH,
I n common with certain other triglycerides, tristearin shows t h e phenomenon of a double melting point, thus apparently existing in two forms. T h e melting point of the stable form, obtained b y crystallization from any solvent, or by keeping t h e unstable form, is variously given as 71.6' t o 72.2'. After barely melting, i t is said by Bomer t o resolidify Heated a few degrees above its melting point, a t 70'. tristearin solidifies on cooling t o the unstable form, which is stated t o melt in a capillary a t about 5 5 " , and on further heating t o resolidify and show t h e melting point of t h e stable modification. The same change t o t h e stable form occurs on standing for some hours a t room temperature. Curiously enough, in spite of t h e rapidity with which conversion into the stabIe form takes place a t higher temperatures, t h e solidification point usually reported for tristearin is about 5 6 ° , 2 apparently t h a t of t h e unstable form. The usual method of determining solidification points 1 Presented in p a r t a t the 52nd Meeting of t h e American Chemical Society, Urbana, Ill., April 18 t o 21, 1916. The quan2 R Kremann and R. Schoulz, Monatsh , 33 (1912), 1063. tities with which they worked are not stated, h u t even with "larger quantities" t h e results were reported t o be t h e same.
