HUDSON AND MOHAWK DISTRICT. 263 



changes their composition, converting the astringent salts of iron into the peroxide ; 2. By 

 ignition, the close texture of the clay bee es open and pervious ; 3. Some of the mate- 

 rials contained in clay, or composing it, become more soluble ; 4. The color of the clay, 

 which by this process becomes red, absorbs more heat, by which the soil, in common 

 language, is changed from a cold to a warm soil ; 5. We may reasonably conclude, that 

 clays, which have been thus treated, become better absorbers of the nutritive gases, as 

 ammonia and carbonic acid. 



'J'lu' operation of paring and burning argillaceous soils can not be followed with injurious 

 effects. Land which is injured by being burned, suffers from the loss of vegetable matter; 

 but they are generally such lands as are cold, or too wet and compact, and require to be 

 drained in order to be cultivated with profit. But to return to the subject of burning clay : 

 Experience has amply proved the benefits of the practice ; and it is probable that it is 

 cheaper to treat clay soils in this way, than to attempt to make them porous by the use of 

 sand, which indeed can not impart so many beneficial results as does the method of paring 

 and burning. 



Waters from the clay beds. 



In this connexion we deem it proper to speak of the composition of the waters which 

 issue from the Tertiary clay, inasmuch as they differ materially from those which are 

 obtained from the general soil of this district. The waters which have been submitted to 

 an examination, were obtained mostly from wells sunk in the clay. The waters of the 

 springs we have noticed possess the same properties as those of the wells, but are some- 

 times more highly charged with sulphate of magnesia : they all contain large quantities ol 

 salts, namely, the sulphates of lime and magnesia, and the chlorides of lime, soda, etc., 

 and sometimes in so great a ratio as to be injurious to the animals which drink of them ; 

 but they are not charged with saline matter in the same proportion at all places. Some- 

 times saline effloresences cover the exposed banks of the clay in dry weather ; at others, 

 large crystals of gypsum are formed in the clay ; and usually, where these saline in- 

 crustations occur, the water is bitter, and animals, especially sheep, if they drink it, are 

 injured, as it brings on the scouring disease. 



The numerous wells in the city of Albany furnish us an opportunity for ascertaining, 

 with sufficient exactness, the amount of saline and other matters contained in the waters 

 issuing from the clay deposit. The first well to which we propose to call the reader's at- 

 tention, is that in the Capitol Park. It is proper to remark here, that the analyses were 

 all made when the wells were well supplied with water, and that probably the relative 

 amount of solid matter is often greater than what appears in the following results. The 

 water of this well gave the following substances on trial : Chlorine, sulphuric acid, lime, 

 magnesia, soda, silex and alumina. One quart of water contains 



