Page:The character and extent of air pollution in Leeds - (A lecture delivered before the Leeds Philosophical Society, on March 3rd, 1896.) By Julius B. Cohen (IA b21534160).pdf/5

 THE CHARACTER AND EXTENT OF AIR POLLUTION IN LEEDS.

INTRODUCTION.

HEN I mention the fact that the solid matter in Leeds air is, on the average, 1&middot;2 milligrammes in 100 cubic feet, I cannot expect that it will convey a very definite idea. Milligrammes are quantities with which most of us are not in the habit of dealing, and even 100 cubic feet is a volume which cannot be realized in a moment. The effect that such a statement will convey therefore depends largely upon the manner in which it is delivered. Thus "the solid matter in the highly polluted air of Leeds amounts to no less than 1&middot;2 milligrammes in 100 cubic feet," will convey an impression essentially different from that produced by the statement, "The minute amount of solid matter in the air of Leeds, one of the most salubrious of Yorkshire towns, may be judged from the fact that it does not exceed 1&middot;2 milligrammes in 100 cubic feet." Perhaps this illustration may serve to explain my reluctance in placing before you results of experiments, which demonstrate little more than we already know, viz.: that Leeds is very smoky, and that it would be highly satisfactory if it were otherwise. But I