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Page:Popular Science Monthly Volume 89.djvu/252

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238

��Popular Science Monthly

��Eradication of Weeds Will Prevent Hay-Fever

AN authority on the subject states 1\ that from the standpoint of the number of patients affected hay-fever ranks among the first of the non-fatal diseases. According to him goldenrod is only responsible for a small percentage of cases, but the common ragweed, with its insignificant green flowers, is directly responsible for a majority of cases.

Besides the ragw-eed, of which two main varieties, the wormwood and the giant, are the most important, there are ten other plants indigenous to the South- ern States, the pollens of which produce hay-fever. They all have the same char- acteristics: they are wind-pollinated; very numerous ; the flowers areinconspicu- ous, with no bright color or scent because insects are not to be attracted, and the pollen is formed in great quantities. The development, duration, and conclusion of hay-fever are synchronous with the pollinating period of the ragweeds, and any elevation under six thousand feet may produce the weeds and the disease to susceptible persons. It would appear that there is a wide difference in the de- gree of susceptibility of different indi- viduals to the pollen. An attack would develop, therefore, only when the expo- sure overcomes the resistance of the sub- ject and only to this extent.

It has been asserted that the pollen, under the influence of the nasal secretion, germinates and sends out its germ tubes, thus producing the irritation. This germination takes place only in the presence of sugar, which is absent in the nasal secretion, and is inhibited by- sodium chloride, which is present. The process of germination usually takes al)out two hours, while the local reaction of hay-fever may take place in a few minutes. The majority of hay-fever patients present no unusual abnormal intransal condition except during the attack, and ojierations for nasal ob- struction, unless indicated for other reasons, have been seldom successful in their intended results, and are rarely advisable. Any of the various treat- ments for hay-fever have not met with conspicuous success, and the sure means will be in the eradication of the weeds causing the disease.

��Protecting Jewelry Store Windows With a Burglar-Proof Curtain

THE thief, brick in hand, awaits his opportunity. When the policeman on beat passes out of sight he slinks down the quiet avenue and takes up a position in front of a jewelry store with an expensive and elaborate window display. Reposing in the right-hand corner of the window is a tray of diamonds. This the thief decides to steal.

Choosing a section of the window where the glass will make the least noise in falling, the thief draws back his right arm and the brick crashes through the window. With lightning agility he thrusts his hand through the broken pane, and then, startled and utterly dismayed, as quickly withdraws it. Had he not done so a burglar-curtain of steel, released from the top of the window at the instant of contact of brick with glass, would have severed his arm at the wrist.

In other words, he was thwarted in his attempt to steal by a burglar-curtain designed to drop and cover the window the instant the glass is broken. In making his superficial examination he had failed to detect the minute strands or wires stretched across the window, several of which were severed when the glass was broken, setting into action a mechanism which released the curtain.

The wires, stretched tight and an- chored at their lower end to a rigid frame and at their upper end to a latch, are arranged close enough so that an object thrown through the pane will sever one or more of them. When this occurs the latch is drawn downward, permitting the retaining rods to mo\e in under forced pressure of their tension springs, which releases a ratchet engag- ing with a shaft round which the curtain is wound. The curtain falls due to gra^•ity.

The dc\ice has been patentetl by Max Richtcr of Chicago, but he does not specify any particular kiml of curtain, although he suggests that steel would be the most effective. A simple safety a|)pliance prevents the curtain from accidenlly falling when the window is being cleaned. It is wound up on the shaft in a "set" position by means of a sprocket wheel.

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