12 
Calcium cyanamid, according to L. Vuaflart, 1 may be tested, for as 
follows: "The presence of calcium cyanamid in a mixture containing 
other fertilizers can be detected by its odor, alkaline reaction, the 
large amount of calcium present, the black residue which is left after 
treating the sample with water, and the yellow precipitate obtained 
with silver nitrate which is insoluble in ammonium hydroxid but sol- 
uble in nitric acid. An impurity often present in the latter is a black 
acetylene silver insoluble in nitric acid- If organic fertilizers are 
present in the mixture, these can be detected by dissolving the 
cyanamid in hydrochloric acid, when the organic matter will remain 
behind as a black residue. Sulphuric acid added to such fertilizers 
will yield a brown solution." 2 
Basic slag contains a rather large amount of material attracted by 
an ordinary horseshoe magnet. The nonmagnetic material is trans- 
parent under the microscope, with a bluish color. It is anisotropic 
and biaxial. Tetracalcium phosphate is monoclinic and the double 
refraction is positive; but this can not always be seen in the com- 
mercial material. The refractive index of the transparent commer- 
cial material is very near 1.64. The biaxial nature and high index 
distinguished basic slag from any of the other substances treated of 
here. 
Shells can be easily distinguished by their obvious shelly structure. 
Cottonseed meal has a predominantly yellow color with brownish 
hull particles, and usually some cotton lint. Often it can be detected 
with the naked eye and is easily identified with the microscope. 3 
Raw hone meal is whitish in color. Mounted in oil, under the micro- 
scope, evident bone structure is seen. 4 
Steamed bone meal is very similar to raw bone meal, and it is not 
always possible absolutely to distinguish the two. The steamed bone 
may be somewhat darker in color, has a friable appearance, and does 
not show the sharp angles and edges seen in the raw product. An 
empyreumatic odor indicates the nature of the material. 
Peat, humus, muck, etc., vary very much. The vegetable matter of 
the material, however, indicates its nature. 
Dried blood, megascopic ally is blackish, dull dark red, and dark 
purplish in color. It is somewhat brittle. Microchemically blood 
may be tested for in numerous ways, e. g., the haemin test, guaiacum 
test, spectroscopic examination of the coloring matter, recognition of 
blood corpuscles, etc. 5 
1 Ann. Falsif., 4 0911.), No. 32, pp. 321-324. Quotation and reference taken from Expt. Sta. Kec, '28, 
804 (1912). 
2 A general discussion of cyanamid will be found in "Cyanamid,'' by E. J. 1'ranko, Easton, Pa., 1913. 
3 For details of cell structure and technique see Ilanausek-Winton-Barber, The Microscopy of Technical 
Products, 1907. 
4 Hanausek, loc. cit. 
s See Allen, Commercial Organic Analysis, Vol. IV, 1898. 
