76 Lime from Gas Works. [August, 



organic matter and nitrate of silver, already spoken of; but soon 

 the deep green color of the salts of copper or nickel will be 

 manifest. 



These facts are sufficient to form a basis for the settlement of 

 the question respecting the genuineness of any coin. Silver or 

 o-okl may be present, but its presence may not be equal to the 

 standard coin; the amount requires the aid of a practical chemist: 

 and it is only when from twenty to sixty per cent of silver is 

 present that doubts will arise. We are not, however, treating of 

 the modes of analysis, but merely of those tests which are quali- 

 ative, and go so far only as to settle a preliminary point. 



Color, sound, feel and smell, though not unimportant, are yet 

 not sufficient in themselves to settle the preliminary question; but 

 if we add to these weight, size and specific gravity, together with 

 the action and results of the action of nitric acid, these will in all 

 cases be sufficient, not only for strong suspicion of guilt but also 

 for a verdict of guilty or not guilty. 



LIME FROM GAS WORKS. 



Lime in the form of what is called milk of lime, is used ex- 

 tensively for purifying coal gas. This lime afterwards becomes a 

 refuse matter and useless to gas makers, and hence is often sold, 

 or has been, in this vicinity, to farmers for agricultural purposes. 



We have stated to several individuals who were about to 

 use this material, that it would probably exert an injurious influ- 

 ence upon vegetation. The experience of this season confirms 

 this statement. It has been found that plants around which it 

 has been put soon become white, and unless very vigorous die in 

 a short time after its application. This effect seems to arise from 

 the offensive gas which escapes, and which acts immediately upon 

 the leaves, which are speedily bleached. The lime of the gas 

 works may therefore be regarded as not only worthless but poi- 

 sonous, and ought not to be used in the state in which it is ob- 

 tained. 



This lime however, might be ignited at a comparatively cheap 

 rate, when the matter so injurious to plants would be wholly ex- 

 pelled. This operation w^ould be attended WMth less expense than 

 burning oyster or clam shells. Or if a kill is in the neighbor- 

 hood of cities where these shells accumulate, both the gas lime 

 and the shells might be ignited together, and lime for agricultu- 

 ral purposes obtained at a cheap rate. 



