VII. LIVER.
For the demonstration of the bile-capillaries Weigert’s neuroglia method gives the best results. (See Page [300].) This method may be used with sections cut on the freezing-microtome after fixation in formol. Such sections are placed in a ½ per cent solution of chromic acid for 1 hour, transferred to the neuroglia mordant for 5-6 hours, washed well with water, and then treated as for the neuroglia method. Van Gieson’s method may also be used for frozen sections of formol-fixed tissue. The walls of the capillaries show as fuchsin-colored streaks.
VIII. MUSCLE.
Van Gieson’s is the best general stain for both striped and unstriped muscle, as it differentiates the muscle perfectly from the connective-tissue. Mallory’s reticulum stain may also be used for the same purpose. For the study of myoglia fibrils the tissue must be fixed within a few minutes after its removal from the living body. Autopsy material cannot be used. These fibrils can be demonstrated by Mallory’s fibroglia stain, or by Mallory’s phosphotungstic-acid hæmatoxylin stain for neuroglia. (See below.)
IX. NERVOUS SYSTEM.
It is impossible in a book on general pathologic technic to consider all of the numerous staining methods that have been devised for the study of the nervous system. I have attempted, therefore, to pick out the best selective methods for the staining of the more important nervous structures, so as to cover adequately the general held of nervous pathology. Formol has now replaced Müller’s for the preliminary fixation of nervous tissue, because of its quick action, and because after its use chromic acid may be employed to mordant the tissue, when it is desired to use certain staining methods requiring such mordanting. Celloidin imbedding is preferable, although paraffin may be used for general work. General stains, such as hæmatoxylin and eosin, and Van Gieson’s are used for general impressions.
1. METHODS FOR STAINING GANGLION CELLS.
A. Lenhossék’s Method.
1. Fix in equal parts of saturated watery picric acid and mercuric chloride (Rabl’s mixture); after-harden in absolute alcohol; imbed in paraffin; cut.
2. Stain in saturated watery solution of toluidin blue, or thionin blue, for 12 hours.