March 28, 1919] 



SCIENCE 



311 



ing morning. Such temperature usually pro- 

 duce immediate and decided effects on vegeta- 

 tion, assuming the character of " killing 

 frosts." 



On the following Sunday morning the writer 

 made a run on the road leading out of Clarks- 

 dale, .which for three miles traverses ground 

 near to what was the bank of the Mississippi 

 Eiver before a " cut-off " several centuries ago 

 converted this part of the river channel into 

 a lake. The road then turns from the old 

 river bank and traverses fields in the interior. 



There is a luxuriant growth of cotton along 

 the road for many miles, and that which is on 

 the ground in the vicinity of the former bank 

 of the river is green and vigorous in appear- 

 ance, showing no effects of frost ; while all the 

 foliage on the cotton in the fields remote from 

 the river bank was completely killed. 



The thermometer that recorded the above 

 temperature is located near the old river bank, 

 and at the same elevation as the growth of 

 cotton stalks referred to. 



The ^vrite^ is unable to imagine an agency 

 that could produce the results above recited, 

 except a difference in the character of the soil 

 in which the cotton grows. 



The soil near the old river bank is com- 

 posed of river silt mainly, while that of the 

 interior fields is a heavy, dark clay, locally 

 called "buck shot." 



The assumption is that the silty soil pos- 

 sesses the property of storing the sun heat 

 during the day, and that this stored heat given 

 out during the night protected the cotton 

 from the frost temperature; and that the clay 

 soil does not possess this property in the same 

 degree. 



The frost temperatures above noted came 

 rather suddenly, without preceding low tem- 

 peratures to deprive the soil of previously 

 stored heat. 



It should have been stated that the " old 

 river channel " above referred to is not now a 

 body of water, but by gradual filling has be- 

 come arable land. Also that this is a level 

 country. 



T. G. Dabxey 



QUOTATIONS 



HOW TO AVOID INFLUENZA 



Although man has lived in houses of one 

 kind or another for several thousand years, and 

 in western Europe since the introduction, 

 somewhere in the fifteenth century, of glass for 

 domestic windows, in houses which can be al- 

 most hermetically sealed, yet a human strain 

 capable of withstanding the evil influences of 

 unventilated rooms has not so far been evolved. 

 Our ancestors of a few centuries ago immured 

 themselves in tightly-closed houses, slept in 

 bedrooms with windows closed, sometimes even 

 in cupboards or box beds with shut doors. The 

 result was reflected in their mortality, in the 

 prevalence of the plague and other plagues, and 

 in their short average span of life. Though we 

 are wiser than they, and pay lip service to the 

 virtues of fresh air, and talk much and learn- 

 edly on ventilation, the severity of the present 

 pandemic of influenza is enough to show that 

 we need to grow wiser. Dr. Leonard Hill, who 

 has done perhaps more than any one else to 

 give a scientific explanation of the air condi- 

 tions of health, makes another contribution to 

 our pages this week in which he relates some 

 interesting experiments on himself and other 

 volunteers. They lead him to urge as the best 

 means of combating the infection of influenza, 

 the deep breathing of cool air brought about 

 by exercise, and by sleeping in the open air — 

 this last perhaps a counsel of perfection. The 

 advice applies not only to influenza itself, but 

 to the colds and catarrhs which, in the aggre- 

 gate, are responsible for so much discomfort 

 and loss of efficiency. A striking illustration 

 has been related to us by Colonel C. T. C. de 

 Crespigny, D.S.O., A.A.M.C. During August, 

 1918, a transport left Australia bound for 

 Great Britain. The 1,200 troops which she 

 carried were accommodated in four troop decks 

 of about equal capacity. Three decks were well 

 ventilated with windsails, but the fourth deck 

 was in this respect very unsatisfactory. 

 Early in the voyage a form of infective pharyn- 

 gitis and epidemic catarrh broke out among the 

 troops. The incidence of the infection was ten 

 times greater among the men occupying the 



