ATMOSPHERE IN RELATION TO HUMAN LIFE AND HEALTH. 329 



The assimilation of atmospheric nitrogen by bacilli connected with 

 certain plants; the results of the fermentation; the possible synthesis 

 within the microbe cell of atmospheric nitrogen and nascent hydrogen, 

 resulting in ammonia. 



The influence of different kinds of weather in developing insect pests, 

 especially those which are destructive to crops. The cultivation of 

 crops in such a manner as to render them as far as possible proof 

 against such pests, by choice of varieties best adapted for resistance 

 and by planting and maturing them at times least adapted for insect 

 attacks. The issue of forecasts of insect prevalence, derived from sys- 

 tematic study of the habits of noxious insects and of the weather of 

 present and previous seasons. 



Experimental investigation of the respiration of plants. 



Germination of plants; its dependence on temperature in a great 

 variety of seeds from different localities and latitudes. The influence 

 of temperature of the air on the formation of chlorophyll, and the 

 activity of assimilation and growth in artificial atmospheres differently 

 composed. 



The relation of wind to health, as regards force, direction, and dura- 

 tion, and with relation to temperature and moisture. The health of 

 cities as affected by mean horizontal movements per hour and by the 

 number of calms; different periods in the same cities to be compared, 

 and the same periods in different cities. The relation of wind and 

 calm to infectious and malarious diseases, taken separately, and to 

 rheumatism, neuralgia, bronchitis, and colds. The generally better 

 health of towns, villages, and dwellings in high situations; how far 

 owing to difference of soil and how far to difference of climate, espe- 

 cially temperature, daily range, and wind. The comparative healthi 

 ness of the upper stories of houses, especially as regards diarrhea, 

 typhoid, rheumatism, malaria, and tuberculosis. The bodily and 

 mental conditions, such as breakdown, fatigue, or depression from over- 

 work, anxiety, or other causes, and all cases of ill health, in which (1) 

 a fine, placid climate and (2) a windy, changeable, moist climate is 

 most beneficial. A comparison of the health and diseases of inhab- 

 itants of wild, windy climates, such as those of northern and western 

 Britain, with the health and diseases of the inhabitants of calm, 

 bright climates, if possible not far removed in latitude. A comparison 

 of the health of sailors on board ships with good, airy quarters with 

 the health of the same class of people in the country on shore in about 

 the same latitudes. 



MALARIA. 



The relation of malaria to various soils, to the aeration of the soil, 

 height of water level, ground respiration, and plant life, with its evap- 

 orative power and emission of oxygen. The distance to which malaria 

 can be conveyed over land and sea, and over fresh water, by the air 

 without losing its infective jiower. The dependence of the vitality oi 



