I 146
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
such as is used in sampling soils and clays. This consists mainly of two blades arranged t o cut a &in. hole and so bent as t o pick u p the material each time. Sufficient amount of handle can be attached t o enable a pile of nearly any depth t o be thoroughly sampled. I n this way uniform sections can be bored into a pile in several places and duplicate samples invariably check, showing t h a t if the materials are p u t into t h e mixture, a correct sample of same can be obtained. T h e following tests were made on four brands of about 1000tons each. Four samples were bored from each bin with t h e sampler as well as a sample being drawn from t h e mill during t h e run of t h e entire lot. The brands being figured t o t h e exact analysis, the slight overrun is evidently due t o shrinkage. "IM" BRAND P,Os KzO
..,21,r5.' BPAND P301 G O 12.55 4.96 12.42 5 . 1 0 12.48 5.12 12.635.03
10.05 7.91 9.92 8 . 0 8 9.96 8.10 9.938.04
12.52 5.04
Mill sample ( ~~ ~~ t~11.964.66 d ) )
Av. (Bored)
"1-8-4"
"2-8-lo" BSAtZD
BR*ND
NHt P.0. K10 1.15 8.05 4.00 0.99 8.18 4 . 1 6 1.03 8.15 4 . 0 6 1.138.024.06
NHI P.06 G O 2.18 8.15 10.20 2.01 8 . 1 0 10.20 2 . 1 1 8.17 10.01 1.968.1810.14
9.97 8.03
I .07 8.09 4.07
2.06 8.15 IO. 13
10.67 7.83
1 . 1 0 8 . 5 0 3.60
2.16 7.80 10.30
_ _ -_
_ _ _ __-
On these "mill" samples it would be necessary t o change the formula which would result in incorrect analyses, whereas the bored samples show t h a t the piles actually run about as figured. Bad analyses on bored samples can invariably be traced t o faulty mixing i n which either wrong amounts were weighed in or t h e actual materials fail t o analyze as figured. I n sampling bagged shipments, we believe t h a t much more reliable information can be obtained as t o their analyses b y t h e use of t h e double tube sampling trier which is inserted into a bag, closed, a n d withdrawn, giving an exact section of t h e material therein. If methods of sampling could be as rigidly enforced in t h e factory as in the laboratory, we believe t h a t more dependable information would result. The average factory chemist does not bestir himself sufficiently t o see when samples are being drawn correctly and the average superintendent does not realize the importance of t h e small details i n sampling, which have a vital bearing on the plant and its reputation for uniform analyses. CXBMICAL L~soamoau.F. S. ROYST*.GUANOCOUPANY N o s ~ o ~Vmarlrrr n,
Vol. 8, No.
12
position on t h e scale of t h e instrument, representing its width and intensity by the width and height, respectively, of t h e drawina. T h e spectrum map paper here described differs from t h a t ordinarily employed in t h a t there is provided above each scale a cross-sectioned area one centimeter in height on which t h e maps are made, using the heavy line as the base line. The vertical lines of the crosssectioned area are useful as guides in mapping spectrum lines, while the horizontal lines simplify the comparison of t h e intensity of lines and hands in different parts of the spectrum. The spectra t h a t are shown were mapped as an illustration of Bunsen's method as applied t o this new map paper. The compounds employed were respectively: lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, caesium alum, calcium chloride, strontium chloride, barium chloride, boric acid, and manganese chloride. The spectra were produced in t h e usual fashion by introducing the sub-
stances into a Bunsen flame on a platinum wire, I n the case of the chlorides of the alkaline earths, where rapidly shifting spectra are first obtained, the m a p s represent the fairly stable spectra t h a t are produced after a preliminary heating of the chlorides on t h e wire.
Received July 17. 1916
This map paper can also be conveniently employed for the mapping of absorption spectra a t different concentrations for t h e determination of t h e point of "minimum brightness" of t h e substance in solution.
The method of mapping emission spectra which was suggested by Bunsen' has proven of value in the course in Opticochemical Methods a t Cornel1 University as an aid in familiarizing t h e student with comparatively simple emission spectra. Bunsen's method consists in plotting the lines and bands of a spectrum on a millimeter scale, numbered t o correspond t o the arbitrary scale of the spectroscope. Each line or band is placed at t h e position on t h e scale t h a t corresponds t o its
The illustration shows a sheet of t h e spectrum m a p paper about one-third natural size. This paper is furnished by t h e Cornell Cobperative Store, Morrill Hall, Ithaca, N. Y . , in packages of fifteen sheets, together with three sheets of millimeter cross section paper, a t a cost dependent upon t h e price of paper. Until recently a package was sold for fifteen cents, postage prepaid, with lower prices on ten or more packages.
A NEW SPECTRUM MAP PAPER BY R. P. A N D B ~ S O N
1
Ann. d n P h w . und Cham.. 106 (1863). IO.
CORN%LL U N I Y B R ( V I I .
Im*cA. NHw Yoax
