e.

The nerve possesses conductivity: although it is stimulated at some distance from the muscles, yet the change excited by the stimulus travels along it to them.

APPENDIX.

The various re-agents, mentioned in the "Laboratory work" in the preceding pages, are prepared as follows:

1. Acetic acid, Dilute.

Mix I cub. centimetre of glacial acetic acid with 99 cub. cent. of distilled water.

2. Ammonic bichromate, Solution of.

Dissolve 10 grammes of crystallized ammonic bichromate in a litre of distilled water.

Dissolve the carmine in the ammonia and water; leave in an unstoppered bottle until nearly all smell of ammonia has gone. Afterwards keep in a well-closed bottle. Dilute a small quantity with fifteen or twenty times its bulk of water, when required for use.

4. Chromic acid, Solution of.

Dissolve 10 grammes of crystals of chromic acid in one litre of water. This gives a 1 per cent. solution, from which weaker ones can readily be prepared when required.

5. Hæmatoxylin, Solution of.

a. Prepare a saturated solution of crystallized calcic chloride in 70 per cent. alcohol; then add alum to saturation.

b. Prepare a saturated solution of alum in 70 per cent. alcohol. Add 1 volume of a to 8 of b.

C.

To the mixture of a and b add a few drops of a saturated solution of pure hæmatoxylin in absolute alcohol. Filter.

6. Iodine, Solution of.

Prepare a saturated solution of potassic iodide in distilled water; saturate this solution with iodine. Filter. Dilute to a brown sherry colour.

7. Magenta, Solution of.

Dissolve I decigr. of crystallized magenta (roseine) in 160 cubic centimetres of distilled water: add 1 cub. cent. of absolute alcohol. Keep in a well-closed bottle.

8. Mayer's Solution.

See note p. 8.

9. Müller's Solution.

Bichromate of potash

Sodic sulphate

25 grammes.

Distilled water

10. Osmic Acid, Solution of.

10 grammes.
I litre.

Best bought ready made in the form of 1 per cent. solution.

II. Paraffin.

Melt together one part of solid paraffin (paraffin candles will do), one part of paraffin oil and one part of pig's lard. A mixture in the above proportions gives, when it has cooled, a mass of the most generally useful consistency.

To imbed an object, scoop a hole in a bit of the paraffin, place the object (the surface of which must be dry) in this hole and fill up the latter with some melted paraffin. 12. Pasteur's Solution.

See note, p. 6.

13. Potash Solution.

Dissolve 5 grammes of potassic hydrate in 100 cubic cent. of water.

14. Schultz's Solution.

Dissolve some zinc in hydrochloric acid; permit the solution to evaporate, in contact with metallic zinc until it has attained a syrupy consistence. Saturate the syrup with potassic iodide, and then add enough iodine to make a dark sherry-coloured solution. The object to be stained must be placed in a little water, and then some of the above solution added.

15. Silver Nitrate, Solution óf.

Dissolve o'5 grammes of silver nitrate in 100 cubic cent. of distilled water. Keep in an opaque stoppered bottle.

16. Sodic Chloride, Solution of. (Normal saline solution. Salt solution.)

Dissolve 75 grammes of sodic chloride in 1 litre of distilled water.

INDEX.