460 Transactions of the American Institute. 



Gas Lime as a Fertilizer. 



Prof. Jas. A. TVhitney read the following paper on gas liine as a 

 fertilizer: The use of gas lime for manurial purposes having led in 

 different eases to totally opposite results, in some causing a great and 

 immediate increase in the growth of grass and grain, and in others 

 materially injuring the croj) and impairing the fertility of the soil, a 

 brief exposition of the nature of the material and the proper method 

 of applying it will interest those desiring to test it. Gas lime is lime 

 that has been used for abstracting sulphur and some empyreumatic 

 substances from coal gas. It differs from oixlinary slacked lime in 

 this, that it contains sulphur and compounds of sulphur. Some of 

 the products thus formed and mingled with the material are ver}'- 

 hurtful to vegetation, while others may be judged to be somewliat 

 beneficial in their action. As hereinafter more fully explained the 

 hurtful compounds exist in the gas lime when fresh from the works, 

 but by judicious management may be rendered harmless and even 

 useful. According to the condition of the gas lime with reference to 

 these impurities will it benefit crops or vice versa^ and this may serve 

 as a general explanation of the discrepancies in the various accounts 

 of results derived from its use. 



The lime used in gas works is obtained by calcining oyster shells, and 

 forms a white pulverulent powder. In a large room provided for 

 the purpose are arranged a number of rectangular wooden boxes, 

 somewhere from four to six feet deep and between thirty and forty 

 across. In these, a few inches apart, are placed horizontal slatted 

 racks, upon each of which is spread a layer of the oj^ster shell lime two 

 or three inches thick, the powdered condition of the lim& making these 

 layers porous so that the gas may filter through them. The gas gener- 

 ated by roasting bituminous coal in the retorts, is made to pass 

 first through water where it deposits most of the ammoniacal matter 

 and gas tar. It is then conducted into the lower parts of the boxes 

 containing the lime as just described. The gas passes up in succes- 

 sion through the several layers of lime. This absorbs the free 

 sulphur, sulphurous acid, and such like impurities, and the gas being 

 purified by the removal of these substances, passes out through a pipe 

 at the top of each box, and is conducted to the gasometer. The 

 quantity of sulpliurous impurities in the gas, and consequently of 

 those taken up by the lime varies somewhat with the nature of the 

 coal from which the gas is made, some coal containing more sulphur 

 and some less, and this agains depends upon the locality from which 



