1898-99.] STRUCTURE, MICRO-CHEMISTRY AND DEVELOPMENT OF NERVE CELLS. 413 
Held®* found the granules are insoluble in weak or in concentrated 
mineral acids. Eve* observed that acids had a slight dissolving action 
on the granules. 
Acids have a marked action on the granules and nuclear contents. 
One way to detect the presence of iron in the cell is to treat the sections 
with acid alcohol, when the iron can be detected by ordinary reagents. 
(vide ante). Ifthe sections are left in the acid for longer time all the 
iron will be extracted from the cell and then on staining them with 
eosin and toluidin blue, no blue-stained substance will be seen, the 
result being the same as if unaltered cells were stained with eosin 
alone. There are no vacuoles in the cell and the granules may still be 
detected with Heidenhain’s hematoxylin stain. After all iron has been 
extracted from the cell the granules in the cytoplasm, the nucleolus and 
the oxyphile nuclear substance still contain phosphorus. 
The action of alkalies on the cell has been studied by Held,® Eve,” 
Bihler” and Ruzicka.* Held and Biihler find the granules are first 
altered in their staining powers and then are soluble in alkalies, 
forming vacuoles in the cell where the granules were originally. 
Eve is doubtful whether the granules are soluble in the alkalies or 
are merely altered in their staining powers. Ruzicka finds the granules 
are insoluble in alkalies and are not altered in their staining properties. 
After treatment with alkalies the granules, I find, do not stain blue 
with toluidin blue or do not give an iron reaction, but most cells do not 
contain vacuoles. Since alkalies detach sections from the slide, either 
loose sections of spinal ganglia were used, or thin pieces of material 
which had been fixed in alcohol were left in the alkali for the desired 
time and then washed, dehydrated and imbedded. As alkalies the 
following solutions were employed: sodium hydrate 0.25 per cent., 
0.5 per cent. and I per cent.; potassium hydrate, 0.2 per cent. and 0.5 
per cent. and lithium carbonate in saturated aqueous solution. Held” 
figures a vacuolated cell obtained by leaving a thin piece of cord in 
saturated lithium carbonate for four days. Material was left in lithium 
carbonate solution for as long as ten days and yet no vacuoles were 
33 Held, Arch. f. Anat. u, Phys., Anat. Abth., 1895, p. 3096. 
34) Lac 
35 Held., H. Arch. f. Anat, u. Phys., Anat. Abth., 1895, p. 396. and 1897, p. 204. 
36 Eve., l.c. 
37 Bihler., |. c. 
38 Ruzicka, Vladislaw, ** Untersuchungen, iiber die feinere Structur der Nervenzellen und ihrer Fort- 
satze,” Arch. f. Mik. Anat., LIII, P. 485, 1808. 
39 Held, l.c., 1895, Fig. 10. 
