IIAC 



HAL 



Gypsum undoubtedly acts chiefly 

 by supplying plants with sulphur, as 

 was suggested by Davy. M. Boussin- 

 gault, however, seems to believe that 

 it does no more good than the same 

 amount of mild lime. It is not of 

 itself a specitic manure for all soils, 

 but is serviceable from the general 

 poverty of lands in sulphur. Ashes 

 of peat and other plants contain from 

 three to five per cent, of sulphate of 

 lime. 



GYRATE. Twisted round in cir- 

 cles. Gyrate (estivation. 



GYRI (from ^vpo^, a circle). The 

 annular series of scales on the tails 

 of some quadrupeds. 



GYROGONITES. Fossil seed- 

 vessels of Characea. 



H. 



HABITAT. In natural history, 

 the natural abode of animals, plants, 

 &c. 



HACK. The roadster, or horse 

 of all work. 



HACKBERRY, HAGBERRY. 

 Celtis crassifolia. A tree chiefly 

 abundant in the central Western 

 States, also called hoop-ash. In Del- 

 aware and the Middle States it is not 

 a large tree, but in Ohio sometimes 

 attains eighty feet. The wood is 

 white, but soft, light, and decays rap- 

 idly : it is used for fences in Ohio 

 and Kentucky. The Indians use it 

 for baskets. It is of very rapid 

 growth. 



HACKLE. A board set with iron 

 spikes for pulling to pieces hemp or 

 flax. An artificial fly used by an- 

 glers. 



HACKMATACK. The American 

 larch. There are two species (Larix 

 ■pemiula and L. rnicrocarpa). They are 

 principally found in Canada and New- 

 foundland, but exist scattered in the 

 Northern and Eastern States. They 

 are so nearly alike as to be consider- 

 ed varieties, attain 100 feet height by 

 three diameter, are straight, and pro- 

 duce strong and durable timber su- 

 perior to the European larch or any 

 American pine. They are esteemed 

 admirable timber in Canada, and used 

 in Maine for ship knees. They are 



very similar in habits and appearance 

 to the European larch. 



H.E.MATITE. Iron ore. 



H-EMATOSIN (from difta, blood). 

 The red colouring matter of blood. 



H.EMATOXYLIN (from diixa, 

 and fu/lov, wood). The red dye ex- 

 tracted from logwood. 



HAEMORRHAGE (from uifia, and 

 f>ayri, rent). A flow of blood, either 

 from an accident or from a full state 

 of body. In the case of wounds, if 

 severe, it may proceed from a torn 

 artery that should be tied with a lig- 

 ature. Constitutional haemorrhages 

 require blood-letting and a low diet. 



HEMORRHOIDS. Piles. As- 

 tringent ointments are useful in com- 

 mon cases. 



HAIL. Atmospheric water con- 

 gealed into lumps of some size, often 

 measuring an inch across. It is al- 

 together different from snow, in oc- 

 curring during the spring and sum- 

 mer. Hail is produced only during 

 violent winds, which carry a great 

 deal of moisture into the upper re- 

 gions of the air, where it becomes 

 solidified by extreme cold. In Eu- 

 rope losses from hail can be met by 

 insurance in companies founded in 

 the same wav as those against fire. 



H A I N H A U L T SCYTHE. See 

 Scythe. 



HAIR. Slender tubes of animal 

 matter analogous to horn. It is an 

 admirable non-conductor of heat. 



Refuse hair ranks as a manure 

 with skin or glue, producing the same 

 results by decay : woollen rags are the 

 most famiUar kind used in this way. 



HAIRS. In botany, transparent 

 tubes of cellulose inserted into the 

 epidermis ; they are totally dissimi- 

 lar from animal hairs, in containing 

 no nitrogen. Cotton is an instance 

 of hairs attached to seeds. 



HAIR GRASS. The genus Aria. 



HALCYONID-E. A family of fis- 

 sirostral birds, of which the kingfish- 

 er is the type. 



HALESIA. The snow-drop tree 

 {H. tetraptcra) ; ornamental trees of 

 South Carolina, introduced into the 

 shrubberies of the Middle States. 



HALHYDRATES. Salts in which 



357 



