, and had become mild ; in the otner case it had 

 acted as a poison. 



It is obvious from what has been said that lime 

 from the magnesian limestone may be applied in large 

 quantities to pea'ts; and that where lands have been 

 injured by the application of too large a quantity of 

 magnesian lime, peat will be a proper and efficient 

 remedy. 



I mentioned that magnesian lime stones efferves- 

 ced little when plunged into an acid. A simple test 

 of magnesia in a limestone is this circumstance, in its 

 rendering diluted nitric acid, or acqua fords milky. 



From the analysis of Mr. Tennant, it appears 

 that the magnesian limestones contain from 

 2O.3 to 22.5 magnesia. 

 29.5 to 31.7 lime. 

 47.2 carbonic acid. 

 0.8 clay and oxide of iron. 

 Magnesian limestones are usually coloured brown 

 or pale yellow, they are found in Somersetshire, Lei- 

 cestershire, Derbyshire, Shropshire, Durham, and 

 Yorkshire. I have never met with any in other coun- 

 ties in England; but they abound in many parts of 

 Ireland, particularly near Belfast. 



The use of lime as a cement is not a proper sub- 

 ject for extensive discussion in a course of Lectures on 

 the chemistry of agriculture; yet as the theory of the 

 operation of lime in this way is not fully stated in any 

 elementary book that I have perused, I shall say a 

 very few words on the applications of this part of che- 

 mical knowledge. 



