1362
.I. G . TVOODMXK :IXD H. P. T A L B O T
n s i u 111 carbonate, and find strong support in observations made elsewhere. Where calcium carbonate instead of riiagiiesiuni carbonate is preseiit in the cultiire solutioiis, the process of iiitrificatioii is niodified, and tlie presence of uiiosidized aiiiiiiotiia does n o t seem to inhibit t h e de\.elopnient of the nitric ferments. Gilder actual soil conditions the forination of nitrites and nitrates may not only occur a t tlie same time, bnt tile nitrites n i a y be oxidized as fast as they are loriiml, and the sctivity of the nitrous ferments inny thus be coiiccaled. It should be iioted here. however, that organisms may exist in the soil, which have the poircr of coiiwrting aniiiioiiia directly iiito nitrate without the iiiternied i n k formation of nitrites. Such, a t least, is the claim made by Kaserer,' atid there are observations mxde by others, which would lend support to this claini.
THE FLUORINE CONTENT OF MALT LIQUORS. 13~ .I G . ~ V O O I I S I A K.%SI)11. P l.11 I m T .
I n a previous paper' the authors outlined a method for t h e approximate estiniatioii of fliioricles when present in niitiute quaiitities, such as might occur in food products. A t that time t h e hope mas expressed that it might be possible to esaiiiitie l ~ yinearis of the niethod, various classes of food products with a view to :!eteriiiiriing t h e limiting values for their fluorine content. For obvious reasons, iiialt liquors seemed excellent material for beginning such an investigation, arid it is the purpose of the present paper to summarize the results obtained in tlie examination of a number of the brands of malt liquor 011 the market, as well as the materials used in brewing. Mct/lod.--The method used was similar to that already described, except that on accoant of the large amounts of carbonic acid in the beers, it was found necessary in every case to add a soniewliat greater quantity of barium acetate, enough being used to ensure an excess iii the filtrate from the barium sulphate and fluoride. For the same reason more sulphuric acid (3-4 cubic centimeters instead of 2-3 as previously directed) is iiecessary during the etcliing. Ai insufficient amount of either of these would occasion negative results, eveu if an appreciable a m o u n t of fliioride were present. In extracting t h e fluoride from malts and barleys it was found inadvisable to grind the sample and extract with hot water, as would be done in t h e brewery operation of mashing, because the large amount of sugary and starchy matters extracted interfere with the subsequent precipitation of the fluoride. Satisfactory results were obtained in the case of malt by Centr. Bakt., Parasitenk., 11, 16, 6S1 ;itid j69 (1906). This Journal, 28, 1437, (1906).
FLUORINE CONTENT O F hlALT LIQUORS
1363
digesting the unground sample with boiling water for three or four minutes, pouring off the water and repeating the operation. In the extract thus obtained fluorides were precipitated i n the usual manner. 1x1 t h e case of barley, where reducing sugars were practically absent, the extraction was made on the ground sample but the digestion was carried out for half an hour at 40°-500, a temperature below the gelatinizing point of starch. Reszdts.-The results obtained with a number of commercial malt liquors and with the principal raw materials of brewing are shown in the following tables. T h e results are stated in milligrams of fluorine per liter, or per kilogram in the case of solids. For convenience, the table of amounts of fluorine corresponding to the different " etching temperatures " given in the earlier paper' is here stated again in this form. T h e values taken are based in each case upon the use of 150 cc. of the samp1.e. With solids, the values will depend upon the weight taken and can be found readily by a simple calculation. Differences due to variations in specific gravity are so slight as to be neglected. T h e samples of beers and ales represented about 50 different brands. T h e samples of malt and barley included both Eastern and Western growths. TABLE I. ~ \ ~ I L L I G R A MO S F FLUORINE P E R LITER ( O R PER KILO) CORREsPONDINC TO THE ETCHING TEMPERATdRES " It'HEK 150 CC. ( I 5 0 GRAMS)ARE USED. Temperature 79O-S2' IO to 40 113O I 36' 173'-178' 213~-21S~
FLUORINE IN MALT ( P E R KILO).
L I Q U O R S AND
I
to
IO
to I O 0 . ~ to 4 0.2 Less than 0.04 0.2
TABLE 2 . BREWING MATERIALS.
&IILLIGRAMS
PER LITER
B
L
OVI
................ ............ I 4 .... I . . . . . . . . 9 .... 2 .... 13 ........................ ........ . . . . . . . . . . . . . . . . I . . . . . . . . . . . . . . . . Y ........ 4 . . . . . . . . g .... 21 . . . . . . . . .... 5 . . . . . . . . .... 5 . . . . . . . .
Barley. 15 Malt. .................. 15 Brewing Sugar. g Domestic Ale a c d Beer .34 Imported Ale and Beer.. 15 3
2
A sample of beer was brewed in the laboratory from materials which had been previously examined and had been found, with the exception of the malt, to be free from fluorides. This was done to determine if, under Loc. cit.
11-ort After .-\cltiitioii of Yeast. (l.
