[18] We draw particular attention to the small number of eosinophil cells, since according to Ehrlich's postulates this absence of eosinophil cells is incompatible with the diagnosis of a leukæmia.
[19] In contrast to this lymphatic metamorphosis of the bone-marrow, in myelogenous leukæmia a myeloid transformation of the other blood-forming organs, especially of the lymph glands is found; a transformation sufficiently characterised as myeloid by the presence of myelocytes, eosinophils, and nucleated red blood corpuscles.
III. ON THE DEMONSTRATION OF THE CELL-GRANULES, AND THEIR SIGNIFICANCE.
During the last ten years a large amount of valuable work has been done on the cell-granules from histological, biological and clinical sides. This has particularly assisted hæmatology, where a number of problems remain whose solution is only possible by the aid of a knowledge of the granules. We must therefore consider the history, methods, and results of this work.
Ehrlich was undoubtedly the first to insist on the importance of the cell-granules, and to obtain practical results in this direction. We are obliged to mention this, since Altmann has, in spite of express corrections, repeatedly asserted the contrary. In 1891[20] Ehrlich refuted Altmann's claim to priority, nevertheless, Altmann in the 2nd edition of his Elementary Organisms (1894) stated that before him no one had recognised the specific importance of the granules, though some authors had viewed them as "rare and isolated phenomena."
We may quote a passage published by Ehrlich in 1878[21], that is, ten years before Altmann's papers. "Since the beginning of histology the word 'granular' has been used to describe the character of cellular forms. This term is not a very happy one, since many circumstances produce a granular appearance of the protoplasm. Modern work has shewn that many cells, formerly described as granular, owe this appearance to a reticular protoplasmic framework. And we have no more right to call cells granular in which proteid precipitates occur, either spontaneously as in coagulation, or from reagents (alcohol). The name should be kept exclusively for cells in which during life substances, chemically distinct from normal proteid, are embedded in a granular form. We can readily distinguish but few of these substances, such as fat and pigment; most of them we can at present characterise but imperfectly, or not at all."
"Earlier observations, especially on the mast cells, led me to expect that these granulations, though they had long been inaccessible to chemical analysis, could be distinguished by their behaviour with certain stains. I found, in fact, granules of this kind, characterised by their affinity for certain dyes, and which could thereby be easily followed through the animal series and in various organs. I further found that certain granules only occurred in particular cells, for which they were characteristic, as pigment is for pigment cells, and glycogen for cartilage cells (Neumann) and so forth. We can diagnose the variously shaped mast cells only by the staining of their granules in dahlia solution, that is by a microchemical test. And in the same way we can separate tinctorially other granulated cells, morphologically indistinguishable, into definite sub-groups. And for this reason, I propose to call these granulations specific."
"The investigations were performed after Koch's method in the following manner. The fluid (blood) or the parenchyma of the organs (bone-marrow, spleen, etc.) was spread on cover-slips in as thin a layer as possible, dried at room temperature, and after a convenient length of time stained. I had chosen this apparently coarse method for the special reason that for the histological recognition of new, possibly definite chemical combinations, corresponding to the granulations, all substances must be avoided that might act as solvents, e.g. water or alcohol, or as oxydising agents, such as osmic acid. In this instance only such procedures may be employed as will leave the simple drying of each single chemical substance as much as possible unchanged."