2 The fat to be analysed is saponified with soda or potash, and then the fatty acid set free by hydrochloric acid. If water be now added, 11 or 12 per cent. of the fatty acid will be dissolved, if the fat is butter; less than this if it is a mixture; and not more than 5 per cent. if no butter is present in the fat.

3 Freshly made; of which 1 c.c. = ·00001 grm. of N2O3

4 Made by dissolving ·395 grm. of KMnO4 in 1,000 c.c. of water. Each c.c. of this solution =·0001 grm. of oxygen available for oxidation.

5 Caused by the liberation of iodine. Thus—

6 Of the strength of 1 grm. of crystalline sodium thiosulphate to 1 litre of water.

7 In practice one has frequently to be contented if the CO2 does not exceed 1 part per 1000 of air; and if the room is clean and free from dust, this higher limit may be accepted.

8 The damp-proof course should have been shown close under the plate carrying the floor joists.

9 Some bacteria form in their interior minute spores, by means of which they are able to resist ordinary destructive agents. These spores again develope into bacteria.

10 Furthermore, it is stated that when at rest on a plane surface the Culex assumes a position with the axis of the body more or less parallel to the surface; while the Anopheles, under the same circumstances, has the axis of its body more or less at right angles to the surface.

11 This is diphtheria attacking the larynx

12 From “Elements of Vital Statistics,” by A Newsholme.

13 This was written before the figures for the period 1891-1900 were available; but the method adopted is the same, substituting the death-rates, etc., for the later period.

14 The death-returns greatly understate the actual death-rate from this cause.

15 There is no general agreement as to the exact sense in which the words average and mean should be used. They are used here interchangeably.