Machinery, again, growing ever more and more complicated, has destroyed an incalculable wealth of traditional activity: and therewith, generation by generation, it tends to destroy the finest capacities of individual men and women, whether producers or consumers of the finished product. The consumers suffer through the lack of opportunity to acquire and exercise manual dexterity and resourcefulness--as well as through a great lack of experimental knowledge. The producers suffer through the monotony and narrowness of their labour. We may take as other instances of recklessness our common use of unprotected illuminants--electric light and incandescent gas-mantles--which give off ultra-violet rays injurious to the eyes; the use of portable electric lamps and switch lampholders, which is by no means free from risk; and again the extreme recklessness of the so-called "medical electrician," who will actually venture to give electrical massage to a patient immediately after wet pack.[12] As a last example we may take the rage for speed, and in particular the use of electrically driven motor-cars. The exact effects upon the human frame of the rapid motion, of the vibrations, of the presence of the electric current and escaping gas have never been adequately investigated--though sundry ill consequences of motor-driving have been noted without any diminution of the practice. A very cursory reflection may show us that, while the progress of science is the great characteristic fact of modern life to which we all have to adjust ourselves, we must be prepared not only to take advantage of the good it offers, but also to discern and counteract the perils it brings with it, when applied to human life in our present somewhat random way.