134 
TIIE WEATHER AND THE PUBLIC HEALTH. 
the flame ought to be more or less opaque ; and as such particles would obstruct the 
light of those situated behind them, we ought to get less light from the edge of the 
flame than from its flat side. With gas of ordinary light-giving powers, we certainly ob¬ 
tain the same illuminating effect, whether the flame be placed edgewise or flatwise with 
respect to the body illuminated. I cannot state positively that the same result would 
he observed if the light proceeded from a flame of very great luminosity. I do not 
assert that the decomposition of hydrocarbons in a gas flame is never complete, that 
under no circumstances whatever does a single particle of elementary carbon separate ; 
but I contend that the incandescence of solid particles is not the chief condition of 
luminosity. According to my view, the luminosity of the gas flame is mainly due to 
the ignition of dense hydrocarbon vapours which result from the action of intense heat 
upon certain of the constituents of coal-gas.”— Laboratory. 
THE WEATHER AND THE PUBLIC HEALTH. 
BY T. L. PLANT, F.M.S., BIRMINGHAM. 
April sustained its character this year. Rain fell on nearly every day in that month. 
The severe gales in the second and third week are unprecedented for April in these re¬ 
cords. The first eleven days of May were remarkably hot. May 8, 82° in the shade. 
Mean of week ending 11th, 61^°—eleven degrees above the average. As this month 
advanced we had a succession of strong north-easterly winds and cold nights, but no 
frost until the morning of the 22nd, when we went into mid-winter weather. That 
day was remarkable for frost and frequent snowstorms from morning till night. On the 
23rd and 25th seven and six degrees of frost respectively. There was nothing in pre¬ 
vious years in the present century to equal it in severity in the fourth week of May. 
The range of temperature between May 8 and 23 was upwards of 50°. It is a signifi¬ 
cant fact that hitherto all excessive heat in the early part of May has been followed l}y 
cold weather in the same month; as in 1807, 1820, 1828, 1833, 1841, 1848, 1864, and 
1867. The last six days of May were very hot. June opened with great heat and 
heavy rains. The weather was remarkably erratic this month. June 10, 118° in the 
sun; June 11, 82° in shade; June 14, 41°; June 11, 9 a.m., 73° in shade; June 17, 
9 a.m., 49° only. 
♦Polar winds prevailed from the 12th to the end of the month. 26th, 27th, and 28th, 
barometer 30^ inches and 30f inches. The mean temperature in each of the three 
months when compared with the average in eighty years was as follows:—April, 2° in 
excess, May 0 9° in excess, and June, 0 3° in deficit. Rainfall in thwthree months 6-19 
inches, being 019 inch in excess. In April and May the barometrical values were 
0-23 inch and 0 09 inch below the average respectively, and in June 0-12 inch above the 
average. 
Spring Season, 1867. 
Table, from Nineteen Years’ Observations, showing , in parallel columns , the Earliest , the 
Latest , and the Average Dates on which the Foliage or Blossom of each of the Trees 
therein named has commenced expanding , compared with the same observations in 1867. 
Earliest. 
Balsam poplar ( Populus balsamifera ) .March 6. 
Larch ( Abies Larix ).March 21. 
Plorse chestnut (TEsculus Hippocastanum) March 17. 
Sycamore (Acer Pseudo-platanus) .March 28. 
Damson blossom ( Prunus domestica ) .March 28. 
Lime ( Tilia europcea) .April 6. 
Beech ( Fagits sylvalica') .April 19. 
Spanish chestnut ( Castanea vesca ).April 20. 
Oak ( Quercus robur) .April 10. 
Ash ( Fraxinus excelsior ) .May 13. 
Mulberry (Morns nigra ) .May 12. 
Latest. 
Average. 
1867. 
April 19. 
March 31. 
April 15. 
April 14. 
April 2. 
April 14. 
April 19. 
April 8. 
April 19. 
April 23. 
April 14. 
April 25. 
May 13. 
April 12. 
April 17. 
May 2. 
April 21. 
April SO. 
May 7. 
April 28. 
May 1. 
May 20. 
May 9. 
May 4. 
May 26. 
May 9. 
May 3. 
June 14. 
May 30. 
May 16. 
June 23. 
June 1. 
May 16. 
