178 RAIN. 



pieces of muslin cloth on the flowering sennega {ciccr arte- 

 tinum, Bengal gram) after sunset, and removing them be- 

 fore the sun gets through the clouds of mist. The moisture 

 with which they are saturated is wrung out, and preserved 

 for use. The acid juice is said to contain oxalic, malic, and 

 a little acetic acid.* 



11. Rain. — The humidity communicated to the air by 

 evaporation is returned to the earth chiefly in the form of 

 rain. The quantity of rain which falls is greatest at the 

 equator, gradually decreasing towards the poles. The quan- 

 tity is estimated by means of the rain-gauge, and is given 

 in inches and fractions of inches. When we say, for ex- 

 ample, that one inch has fallen in a district in a specific 

 time, it means that if all the rain which fell in that time had 

 remained on the surface, it would have covered it to the 

 depth of one inch. This explanation is offered, as some of 

 our readers might not be aware without it of the precise 

 meaning of the following details. 



In India the rains occur at determinate periods, named 

 the rainy seasons. In general there is but one rainy sea- 

 son, during June, July, August, September, and October, 

 during the south-west monsoon ; little or no rain falling 

 in the other months. In the peninsula, however, there 

 are in some places lico rainy scaso7is, — one during the 

 south-west monsoon on the west side, the other in the time 

 of the north-east monsoon on the east side of the country. 



Rain falls, not only all over the peninsula and Middle In- 

 dia, but also among the Himmalehs, and at a great height 

 above the sea. Thus Gerrard, in a snow-covered region 

 15,000 feet high, experienced a shower which lasted for 

 two hours. He was also detained three days by incessant 

 Tain at Shalpia, a resting-place for travellers. 



On the coast of Malabar, mean latitude about 1U° north, 

 the annual amount of rain is stated at 123^ ; at Bombay, 

 the fall observed during twelve years is stated at 82 inches 

 annually ; at Calcutta 81 inches during the year. Of the 

 quantities falling during successive months the results are 

 necessarily very variable. The means of twelve years' ob- 

 servations for Bombay afford the following results : — 



* Dew collected from the loaves of plants contains a large dose of car- 

 tonic acid ; thus Lampadius found 2 per cent, of carbonic acid in dew 

 collected from the leaves of the akhcmilla vulgaris. 



