34 



OF THE SOLUBLE SALINE MATTER IN THE SOIL. 



[AppeTidix, 



saline matter may be obtained;* it will be proper, therefore, briefly to state 

 the methods by which the respective quantities of each constituent may be ac- 

 curately determined. 



a. EsliinalLon of the Salpkuric Acid. — The solution being gently warmed, a 

 few drops of nitric acid are to be added until the solution is slightly acid, and 

 any carbonic acid that may be present is expelled, after which nitrate of baryta 

 is to be added to the solution as long as any thing falls. The white precipi- 

 tate (sulphate of baryta) is then to be collected on a weighed filter, well washed 

 with distilled water, dried over boiling water as long as it loses weight, and 

 then weighed. The weight of the filter being deducted,! every 100 grains of 

 the dry powder are equal to 3 137 grains of sulphuric acid. 



b. Estiviatioii of the Chlorine. — The solution of nitrate of silver must be add- 

 ed as long as any precipitate falls, the precipitate then washed, dried at 212^^ F., 

 and weighed as before. Every 100 grs. of chloride of silver indicate 24-07 grs. 

 of chlorine, or 40-88 grs. of common salt. 



c. Estimation of the Lime. — A little diluted muriatic acid being added to throw 

 down the excess of silver, and a little sulphuric acid to separate the excess of 

 baryta, added in the former operations, and the precipitates separated by fil- 

 tration— caustic ammonia is to be poured in, till the solution is distinctly alcaline. 



' This is the case with the rich soils of India and Egypt, and of other warm climates. 



This will appear from the following analyses of some Indian soils, made on the spot by Mr. 



Fleming, of Barochan, during the hours of leisure left him by his more important duties :— 



Analysis of soils in North and South Bchar^ Bengal Presidency — (200 grains of 



each being analysed.) ' 



REMARKS. 



1°. Near Gy a, South Behar.— Of a dark colour, soapy 

 to the touch when moist, hard and cracks when dry ; 

 yields a crop of rice and one of wheat every year. Ne- 

 ver lies fallow, but is covered with water during part of 

 the rainy season, and is productive — from 30 to 50 

 bushels of wheat per acre. 



2°. Soil from the same district. — Also soapy when 

 moist and cracks when dry— rather more productive 

 than No. 1. 



3°. From the same district. — Heavy red clay soil, 

 producing wheat, pease, cotton, or poppy in the dry 

 season, and Indian corn and millet in the wet season ; 

 not inundated in the rains, and sometimes manured 

 with ashes of wood and row dung. 



4°. Soil from North Behar, Tirlvoot. — A deep loam, 

 yielding two crops yearly; not inundated, producing 

 wheat, barley, Indian corn, indig;i, poppy, &c. From 

 25 to 35 bushels of wheat per acre ; is not usually 

 manured. 



5°. Tirlioot. — Soil light coloured ; producing nearly 

 the same crops, but not so productive as No 4. Saline 

 efflorescence in patches. 



6°. Tirlioot. — Not so productive as No. 5, and some 

 patches nearly sterile from the saline efflorescence, 

 except in the rainy season, when it produces good 

 crops of Indifll corn. Soil light coloured. 



I have already alluded (Lecture VIII., p. 159) to the influence which this large proportion 

 of saline matter exercises upon the luxuriance of the vegetation. 



t Or the whole may be heated to redness in the air, and the filter burned away. In this 

 case the weight of ash left by the paper must be ascertained by previous trials, and the du« 

 proportion deducted from the weight of the sulphate. 



