THE TECHNOLOGIST. [Sept. 1, 1864. 



96 SCIENTIFIC NOTES. 



it be again expelled by boiling. When there appears to be oil enough 

 on the surface of the water, pour in a pailful or two of cold water to 

 stop the boiling, or let the fire burn down. Now dip off the oil into 

 some clean vessel, and boil the bones again until there is oil enough to be 

 dipped off again. The oil that is obtained by the first boiling is purer 

 than that which is obtained at the second or third boiling. There will 

 be some water among the oil which must be evaporated ; therefore, put 

 the oil in a clean kettle and heat it just hot enough to evaporate the 

 water, and the oil will be ready for use. Great care must be exercised 

 in heating the oil, so as not to burn it. As soon as the oil begins to 

 simmer a little, the oil may be removed from the fire, as the water has 

 evaporated. Water in oil, heated to the boiling point, will be converted 

 into steam almost instantaneously, as may be seen by allowing a few 

 drops to fall into boiling oil or hot lard. (This occurs from the dif- 

 ference of temperature at the boiling point of the two liquids, that of 

 linseed oil being 597°.) Let the oil be kept in a jug corked tightly, and 

 it will be ready for use at any time for years to come. In very cold 

 weather, however, it will require a little warming before using it. 



Teasels (Dipsacus fullonum) are the dried heads of a biennial plant 

 which is extensively cultivated in the woollen manufacturing districts 

 and on the Continent, for its uses in raising the nap upon woollen stuffs, 

 which it does by the rigid hooks of the heads. Without this plant, our 

 woollen manufactures coidd hardly have made such progress. It appears, 

 from many attempts, that the objects designed to be effected by the 

 spiny bracts of the teasel cannot be so well supplied by the mechanical 

 •contrivance of metallic wire " cards," and successive inventions have been 

 abandoned as defective or injurious. The dressing of a piece of cloth 

 consumes from 1,500 to 2,000 teasels. They are repeatedly used in 

 different parts of the process. The largest burs, and those most pointed, 

 are esteemed the best, and are called " male teasels ;" they are mostly 

 used in the dressing and preparing of stockings and coverlets. The 

 smaller kind, properly called the " fuller's, or draper's teasels," and some- 

 times the " female teasel," are used in the preparation of the finer stuffs, 

 as cloths, sateens, &c. The smaller kind, sometimes called " linnet's 

 heads," are used to draw out the nap. The dealers give them peculiar 

 names, according to their size and shape, &c, as " Kings," " Queens," &c. 

 The teasel heads are set in a long frame of iron bars, when used for 

 carding. Although not specified in the official trade returns, upwards of 

 twenty millions of these teasel heads are imported annually from 

 France. 



