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A systematic investigation on the heavy primary cosmic radiation is made on the basis of extensive analysis of the Prince Albert Stack. The experimental methods used in nuclear emulsion work for the determination of the charge and energy of the heavy primary are critically discussed and summarized. The experimental result described here is the first, and to date the only one, to give information on the rigidity spectrum of various components of heavy primaries in the low region. The general shape of the spectrum, common to all components, is found to have a broad maximum which falls around 2.2 Gv with a width of about 0.6 Gv. The flux values above the atmosphere of the various components are as follows (in units of particles/m2 · sec · strad.): <tbl id="table1" loc="float"><tblbdy top-stubs="1"><r><c cspan="1" rspan="1"></c><c cspan="1" rspan="1">1.3<<it>R</it><2.7 Gv</c><c cspan="1" rspan="1"><it>R</it>>2/7 Gv</c></r><r><c cspan="1" rspan="1">He</c><c cspan="1" rspan="1">40.6 ± 5.2</c><c cspan="1" rspan="1">81.1 ± 7.2</c></r><r><c cspan="1" rspan="1">L</c><c cspan="1" rspan="1">1.15 ± 0.13</c><c cspan="1" rspan="1">1.61 ± 0.15</c></r><r><c cspan="1" rspan="1">M</c><c cspan="1" rspan="1">3.64 ± 0.32</c><c cspan="1" rspan="1">6.39 ± 0.80</c></r><r><c cspan="1" rspan="1">H</c><c cspan="1" rspan="1">1.24 ± 0.16</c><c cspan="1" rspan="1">1.87 ± 0.18</c></r></tblbdy></tbl> The effect of solar activity on the heavy primary cosmic radiation is discussed on the basis of the observations by the present authors compared with others. Our knowledge of the chemical composition of heavy primaries and its comparison with the astrophysical data on the abundance of various elements enable us to discuss the origin of cosmic rays. The chemical composition of heavy primaries has the following remarkable features: <l type="roman"><li> Fe group elements are overabundant as compared with their abundance in usual stars. </li><li> C is overabundant in C, N and O group elements as compared with usual stars. </li><li> Ne is underabundant when compared with its abundance in stars and, at the same time, the abundance of Ne is comparable to that of Mg. </li><li> On the whole, it is very similar to that of planetary nebulae up to elements of <it>Z</it> ∼14. </li></l> This fact as well as the consideration about the production efficiency of the cosmic ray particles makes it very plausible to consider that the main contribution to the cosmic ray component up to <it>Z</it> ∼14 seems to come from late-stage giant stars whereas supernovae account for the component of <it>Z</it> &gsim; 20.