Section Cutting and Staining A practical introduction to histological methods for students and practitioners — Reading Companion

Apparatus and Hardening

The first chapter lists necessary apparatus, but Colman quickly moves to the critical step of hardening tissues. He emphasizes that proper hardening is essential for successful section cutting, and describes various fluids such as Müller's fluid, which is used for prolonged hardening before staining nerve fibres. The author notes that tissues must be hardened for many weeks in bichromate solutions to achieve optimal results with Weigert's method.

Colman's approach is methodical: he explains the purpose of each step, such as dehydrating in alcohol before embedding in celloidin. The text includes practical tips, like transferring hardened tissue without washing to absolute alcohol. This attention to detail reflects the book's aim to guide practitioners through reproducible procedures.

Staining Techniques for Nerve Centres

Chapter VI focuses on special methods for staining nerve fibres, primarily Weigert's method and Pal's modification. Colman explains that these techniques stain the myelin coating, while degenerated fibres remain unstained, appearing as light spots on a dark background. The process involves overstaining in haematoxyline solution, then differentiating with a bleaching reagent until the ground tissue is decolourised.

Pal's modification offers quicker and more complete decolouration of neuroglia and nerve cells. Colman provides precise measurements for solutions, such as haematoxyline 1/4 grain, alcohol 10 minims, and distilled water 1 ounce. He also notes that staining occurs more rapidly if the fluid is kept at 100°F in an incubator. These details allow the reader to replicate the methods accurately.

Special Stains for Micro-Organisms and Blood

Chapter VII covers staining methods for micro-organisms and blood, including the Ehrlich-Biondi stain, which is used for blood specimens, studying karyokinesis, and investigating supposed parasitic bodies in cancer cells. Colman gives the exact formula: mixing saturated aqueous solutions of Orange G, Rubin S, and Methyl Green OO in specific proportions, then filtering the copious precipitate.

He advises that the solution must be made up frequently as it does not keep well. Sections can be stained rapidly for half an hour, but better results come from diluting the fluid with twenty volumes of water and staining overnight. The instructions are clear: wash in water, pass rapidly through absolute alcohol and xylol, and mount in Canada balsam. This section demonstrates Colman's commitment to reproducible, practical guidance.

Colman's manual is best approached as a laboratory companion rather than a textbook. Readers should have basic histological equipment at hand and follow the steps sequentially, noting the specific timing and concentrations. The book's value lies in its detailed protocols, which were tested in practice. For modern practitioners, it offers a historical perspective on techniques that underpin contemporary neurohistology and pathology.

There’s something tender about old lab manuals—all those careful, patient hands. I finished the staining guide and kept thinking about quiet devotion to tiny things. It drifted me toward this other old book, which holds a similar warmth for curious eyes. Essays on the Microscope Containing a Practical Description of the Most Improved Microscopes, a General History of Insects, etc., etc. — Inside the Classic lingers like a familiar afternoon.