THE FARMER AT HOME. 229 



which is black. Great quantities of it have been dug up in the 

 Pyrenees ; and it is also found in parts of Portugal, Spain, Italy, Ger- 

 many, Prussia, Sweden, and Ireland. It bears a good polish, and is 

 made into trinkets. It is also reduced into powder, formed into a 

 varnish, and, when mixed with lime, it is an extremely durable 

 cement. 



JOINTS. The joints of the human body are called by anatomists 

 articulations. The suppleness to w r hich the joints maybe brought 

 by long practice from infancy is very surprising. One of the most 

 wonderful instances was a person of the name of Clark, and famous 

 for it in London, where he was commonly known by the name of 

 "Clark, the posture-master." This man, by long practice, distorted 

 many of the bones, of which nobody before had ever thought it possi- 

 ble to alter the position. He had such an absolute command of his 

 muscles and joints, that he could almost disjoint his whole body; so 

 that he once imposed on the famous Mullens by his distortions, in such 

 a manner, that he refused to undertake his cure ; but, to the amaze- 

 ment of the physician, no sooner had he given over his patient, than 

 he saw him restore himself to the figure and condition of a proper man, 

 with no distortion about him. 



JUICES OF PLANTS. The proper juice of plants, that which 

 is essential to their growth and nutrition, is the sap, after it has 

 undergone the changes consequent on being received into the circula- 

 tion of the plant. It seems to be elaborated from the sap, by the 

 vital power of the plant, and hence varies much in different plants. 

 .In some, it is sweet, as the sugar maple ; in others, acrid or corrosive, 

 as in the wild parsnip ; in others, narcotic, as in the poppy ; in others, 

 aromatic, as in cinnamon. The color of the proper juices of plants, 

 varies as much as their qualities. In the milkweed it is white, in the 

 periwinkle green, in the celandine yellow, in bloodroot or logwood 

 red, and in others clear and pure. The medicinal qualities princi- 

 pally reside in their proper juices, of which the balsam and turpentine 

 of the fir and pine, are familiar instances. 



Although it was long doubted, it now seems to be generally ad- 

 mitted, that there is a proper circulation of the juices of plants, as the 

 result of their organization. Indeed, in some plants this current is 

 clearly seen, by the microscope, as is exhibited in the plates of Roget's 

 Vegetable Physiology. Such a function, in some form, seems neces- 

 sary, or plants would be unable to free themselves from unnecessary or 

 adventitious matters which are taken up by the sap, as it is clear they 

 do by the process of excretion. Professor Knight's account of this 

 circulation and its results, in substance, is as follows : When the 

 seed is planted under favorable circumstances, moisture is absorbed, 

 and slightly modified by the cotyledons, is conducted to the radicle, 

 mingled with that continually taken up from the soil, ascends to the 

 plumelet, which now expands, and gives the due preparation to the 



