FOOTNOTES

1. Turner's Chemistry, by Liebig and Gregory, 8th ed. p. 206.

2. See Med. Gaz. vol. xlviii. p. 1092; and Comptes Rendus, t. xxx. p. 52.

3. Quarterly Journal of Science, 1829, Part II., p. 354.

4. See Liebig's Agricultural Chemistry, 2nd ed. p. 258.

5. The self propagation of the process of decomposition in the urine is a subject of great importance in a medical and surgical point of view. See a paper on alkalescent urine and phosphatic urinary calculi, Med. Gaz. Nov. 20, 1846.

6. See Schleiden's Principles of Scientific Botany, translated by Dr. Lankester, p. 36; and Liebig's Agricultural Chemistry, 2nd ed. p. 282. Schleiden is of opinion that the yeast cells originate without the influence of a living plant. If it be so, their formation may be looked on as a natural link between the non-vital and the vital -- between ordinary chemistry and physiology. The words of Schleiden are: "At a certain temperature, which is perhaps necessary to the chemical activity of the mucus, there originates, without as it appears the influence of a living plant, a process of cell-formation (the origin of the so-called fermentation fungus), and it appears that it is only the vegetation of these cells which produces the peculiar changes that occur in the fluid."

7. Schleiden, however, speaking of vegetable cells, says, -- "If further we regard the easy transformation of the assimilated matters, and may, from artificially conducted experiments, draw the conclusion that the nitrogenous matter which I have called mucus, and which forms the cytoblast, is the substance which calls forth these transformations; and if we further remark that sugar and dextrine are more easily soluble than jelly, and that sugar and gum are changed into jelly, if the quantity of water is not increased, and which must be necessarily precipitated, we must regard the whole process of cell-formation as simply a chemical act. The gathering together of granules of mucus to form a cytoblast we can as little explain as that, when we form a solution of two salts, if we throw into the mixture a crystal of one or other salt, that salt alone crystallizes around it." -- Opus cit. p. 36.

8. Owen on Parthenogenesis, p. 62.

9. The word contagious is employed in a very different manner by different authors, and it could scarcely be employed, if any regard were paid to its etymology, to express some of the indirect modes of the communication of disease alluded to in the following pages.

10. See a paper by Mr. Grove, of Wandsworth, Med. Times, vol. xxiv, p. 640.

11. Astruc, lib. i. ch. iv.

12. I do not deny that the period of life, being ill or well nourished, and other evident conditions of the patient, influence his liability to certain epidemic diseases. The predisposition objected to above is that which is assumed, without any symptoms of its existence, merely from the fact of the patient taking the disease.

13. Svo. 1842, p. 66.

14. Essai de Geographie Medicale, p. 63.

15. Page 94.

16. De aere, aquis et locis.

17. See Bancroft on Yellow Fever.

18. Dr. Jenner lately called my attention to an instance occurring at the village of North Boston, Erie County, N. Y., in which typhoid fever was probably communicated to a number of families by the contamination of the water of a well which they used. See Clinical Reports of Continued Fever, by Austin Flint, M.D., Buffalo, 1852, p. 380; also, Med. Times and Gazette, March 12, 1853, p. 261.

19. Snow on the Mode of Communication of Cholera, p. 12; Med. Gaz. vol. xliv., p. 747; Med. Times, vol. xxiv., p. 561.

20. The following table from p. 2 of Mr. Alex. Thorn's Report of the Cholera at Kurrachee shows the progress of the outbreak: --