or Sulphate of Iron, as a Mam/re. 5§ 



shows that prohably these arc seeds buried in the earth for 

 many ages, whieh yet remain alive, but do not grow until 

 exposed to the stimuh of air, water, calorific, and Ut'eless 

 animal or vegetable matter. 



APPENDIX. 



The following facts, lately discovered by most respectable 

 chemists, appear to be worih adding to the preceding me- 

 moir, as they serve to show that other salts, besides sulphate 

 of iron, and certain earths, may be employed advantageously 

 as manures, although, like iron, they have been esteemed 

 deleterious to plants. 



1 . Ashes of Pit Coal are a good Manure for Grass. 



My much valued friend, the Rev. Wm. Grcgor, of 

 Grampoundj on examination ol" the ashes of coal IVoni Li- 

 verpool, found ihcni to contain both sulphate of magnesia ^ 

 and sulphate of lime, especially the former, salt. I appre- 

 hend that these ashes also contain oxide of iron, or perhaps 

 sulphate of iron. These ashes, says Mr. Gregor, skeaded*' 

 over grass apparently produced good effects notwithstand- 

 ing the sulphate of magnesia, which I was well assured they 

 contained. (See Nicliolson's Journal, vol. v. p. 225.) 



From this observation of Mr. Gregor, it seems he is 

 aware of the prevailing popular opinion, that sulphate of 

 magnesia is not favourable to vegetation j and to reconcile 

 his fact with the unfriendly nature of magnesia to plants, as 

 discovered by Mr. Tennant, he observes that the effects of 

 sulphate of uiaifnesia may be very difierent from those of 

 magnc-^ia and carbu;: ile of magnesia. I apprehend it is the 

 magnesia (calcined m^ngnesia) only which this learned che- 

 mist found hurtful to vegetables, as the discov^ery was made 

 on the cxaminalion of Nottingly lime, which the farmers 

 near Doricasttr employ as a manure, while they reject the 

 lime of their own neighbourhood. In the latter Mr. Ten- 

 nant met with magnesia, and in the former none. (See 

 the account of this important discovery in the Philosophical 

 Transactions;.) 



2. The Earth from Ashes called Cbi'is, is a durable and ef- 

 ficacious Ma/ii/re: In/ Professor MiTCHiLL, of Neiv Yorh, 

 one of the Representatiues in Congress. Addressed to Dr. 



l^EAKSON. 



Dr. Mitchill, in a letter addressed to me on cinis, or 

 r.ir'.b f^.Miid in tlie ashes of wood, has ijia.de some observa- 



• From 2ki*««>. 



tiona 



