\HT 



\VAKM;!:IA. 



WATKR. 



114 



WAUXK'KIA, a genus of Plants named after Mr. Warner. Thi 

 genus, which U now called JlyJrattii, ha* but a single specie*. It 

 belong* to the natural order /tannnculaceir. The calyx ii cospo*ed 

 of three orate sepals. The petal* are wanting. The itameni and 

 orarie* are numerous. The fruit i* baccate, numerous, collected into 

 ah*ad;l-eelled,2aeeded. 



II. Ca*adei>ti* is a email perennial herb, with tuberous root*. It 

 U a native of North America, in watery place* in tract* along the 

 Alleghany Mountains, from Canada to Carolina, The head of it* 

 fruits very much resemble* that of the raspberry. The root of this 

 plant has been used both for dyeing and in medicine. It give* a 

 beautiful yellow colour, and on that account ha* been called yellow- 

 root .It is bitter, and acts on the system u a tonic, and for this 

 purpose is recommended by Professor Barton. 



WART-CRKSS. [SENEBIEBA.] 



WAKT-HOQ. [SuiDJL] 



WARWICKITE, a Mineral, occurring in prismatic crystals of a 

 brownish to an iron-gray colour, often tarnished, bluish, or copper- 

 red. Lustre metallic, pearly to imperfectly vitreous or resinous. 

 Hardness 5 to 6. Specific gravity S to 3-3. It is infusible before the 

 blow-pipe. It is an American mineral, and is found in Magnesiau 

 Limestone. Professor Sbepard sajs it is a fluo-titnnate of iron, with 

 tome yttria. It has since been examined by Mr. Hunt, who says it 

 contains no fluorine, and pronounces it to be a silicate and titanate 

 of iron, magnesia, and alumina, with 7 per cent, of water. He calls 

 it Knceladile. (Dan*. Mineralogy.) 



WA-sHIXOTOXITE. [TlTAMCJl.] 



WASPS. [VE8PID.F.] 



WATKK, in its liquid, aeriform, or solid state, is universally diffused 

 through nature. It was once considered as one of the four elements, 

 and is in common language still frequently so termed. Water how- 

 ever U now known to be a compound substance, consisting of hydrogen 

 and oxygen, in the proportion of two volumes of the former gas and 

 one volume of the Utter; or by weight it is composed of 1 equivalent 

 of hydrogen, 1, and 1 equivalent of oxygen, 8, = 9, its equivalent : it 

 is in fact a protoxide of hydrogen. 



Water is colourles.*, transparent, inodorous, and insipid; it is an 

 imperfect conductor of beat and electricity ; it is very slightly com- 

 pressible, yielding only about 46'65 milliouths of its bulk to the pres- 

 (ur* of the atmosphere. It* specific gravity is 1, being the unit to 

 which the density of all liquids and solids is referred, as a convenient 

 standard, on account of the facility with which it is obtained in a 

 pure state. A cubic inch of water at 62 Fahr, and 30 inches baro- 

 metric pressure, weighs 252'453 grains, and as a cubic inch of 

 atmospheric air weighs 0'31 grains, it is rather more than 815 times 

 heavier than an equal volume of air. 



Water, like all other fluids and substances, expands by exposure to 

 an increase of temperature, and, with a curious exception, the dilata- 

 tion within certain limit* is proportionate to the degree of heat to 

 which it is subjected. When water is cooled to 40 it is at the point 

 of its greatest density, it then goes on expanding as it cools till 

 reduced to 82*, when it solidifies, and this constitutes the exception 

 to the law of contraction by reduction of temperature. If water at 

 40 be heated, it expands a* the temperature rises, aud this is con- 

 formable to the general law. This expansion of water by cold pro- 

 duce* very important effect* in the economy of nature; for if it 

 increased in density, the frozen portions would sink down successively, 

 and thus Urge bodies of water would become masses of solid ice. 



The force with which water awumes the solid state is so great, that 

 iron vrwl* of great thickness have been burst by it; and glass-vessels 

 or lead-pipe* are well known to be destroyed in winter time from the 

 tame cause. Ice i* lighter than water, it* density being 0'!>4, and 

 hence it float* on water. 



Water i* commonly divided into certain heads, according to the 

 source whence it i* obtained, namely, into Atmospheric Water, in- 

 cluding rain and dew ; and into Terrestrial Water, comprising spring, 

 river, well, lake, marsh, and sea-water ; and, lastly. Mineral Waters. 

 Water i* seldom found in a state of perfect purity, but, from its great 

 nolvent and absorbent power, it i* impregnated with a variety of saline 

 mibstanoee, gues, and animal and vegetable subntances, either living or 

 undergoing a process of decomposition. The effect of these U to com- 

 municate different properties, and generally give it a peculiar taste, 

 and not unfrequeutly an odour, which, if not cognisable by the blunted 

 MOM* of man, is so by animal*, especially the camt-1, which can scent 

 water at a great distance in the desert The specific gravity is often 

 much inrreuwd, especially that of sea-water and of mineral-waters, 

 from the taline ingredient*, and of some of the great rivers, from the 

 quantity of mud and other matters which they contain. 



Kain- Water U commonly reckoned the purest ; but it is by no means 

 no free from accidental impregnations as i* generally supposed. What- 

 ever foreign ingredient* exist in the atmosphere of any place are 

 lirought to the ground by the first rain that fulls thus it often con- 

 tains nitric acid, carbonic acid, and chlorine; minute quantities of 

 iron, nickel, and tnangancte ; a* well a* of a peculiar organic sub- 

 stance, chemically different from the extractive matter and the gluten 

 of plants and animals, called Pyrrhine. (Daubeny, 'Report,' p. 1.) 

 Occasionally phosphoric acid is found in it, especially when the wind 

 blow* from the north-west Much more important i* the presence of 



ammonia, first pointed out by Liebig (' Chemistry in it* Application to 

 Agriculture') as the chief source of the nitrogen found iu plant*. 

 Rain-Water, from its grest purity, has high solvent powers, which fit 

 it well for the part it has to perform in the economy of nature, and 

 also for many operations in the laboratory. In this respect it is nearly 

 equal to distilled water. When collected in the neighbourhood of 

 towns however, it require* to be boiled and strained ; and is always 

 contaminated with some soluble and generally dangerous salt of lead, 

 when collected from leaden-roofs or transmitted through leaden pipe* 

 or cisterns. 



Dew differs little from rain, nave iu containing more atmospheric 

 air. Ice-Water differs, when first obtained, from rain, it being desti- 

 tute of atmospheric air, and hence it cannot sustain respiration in 

 fishes ; it is for the same reason mawkish and insipid ; but by exposure 

 to the air it speedily absorbs a due proportion. Snow-Water is nearly 

 similar. 



Spring- Water is of various degrees of purity, according to its source 

 and the strata through which it passes. Its most common source i* 

 rain, which percolates through some of the superficial strata, and, 

 meeting with some obstacle, i* forced up to the surface. Hence it 

 contains most of the ingredients found in rain-water, and frequently 

 also various saline principles, especially chloride of sodium and salt* 

 of lime ; when these lost are abundant, the water is what is termed 

 ' hard,' though this quality is derived in some cases from other saline 

 principles. " Large springs are in general purer than small one*, and 

 those which occur in primitive countries, and in siliceous rocks or 

 beds of gravel, necessarily contain the least impregnation." (Dr. Paris.) 

 Such is the great purity of some springs, that their specific gravity U 

 almost the same as distilled water. The specific gravity of the spring 

 iit Malvern is only 1*0002. 



All spring-waters are more or less charged with carbonic acid gas. 

 The sources of this are various, but the following mar bo mentioned : 



1. The atmosphere. Water has the power of absorbing carbonic acid 

 gas, and that which is contained in the atmosphere, resulting from 

 combustion, respiration, and other processes, is absorbed by water. 



2. The decay of animal and vegetable matters and soils, through 

 which waters percolate supply a certain quantity of carbonic acid. All 

 the wells in London which receive water from the surface drainage 

 contain so large quantities of carbonic acid a* to render them spark- 

 ling and more pleasant to drink ; although the source of the carbonic 

 acid points out the dangerous nature of the waters. 



3. Water passing through strata in volcanic districts is frequently 

 charged to a great extent with carbonic acid, as the waters of Carls- 

 bad, Spa, Pyrmont, Sellers, and many other places on the continent 

 of Europe. This would seem to arise from the carbonic acid, iu com- 

 bination with lime and other materials in the interior of the earth, 

 being set free by the internal heat of the earth, finding its way to the 

 strata, through which springs flow. 



Spring waters contain saline constituents, according to the nature 

 of the strata through which they flow. Waters percolated from the 

 filth of a town, as in the well-waters of London, contain Urge quanti- 

 ties of chloride of sodium. Nitrates ore found as the result of the 

 decomposition of uitrogeneous matters, and also sulphates and phos- 

 phates from the same source. Water from the chalk contains carbonate 

 of lime. The springs near the salt-mines of Cheshire contain chloride of 

 sodium, also iodine and bromine. In the neighbourhood of deposit* 

 of oxide of iron or sulphuret of iron, the springs become impregnated 

 with this substance. When a water contain* so large a quantity of 

 any of these substances as to have its physical characters much altered, 

 it is called a Miueral- Water, or Mineral-Spring. The study of the 

 composition of mineral-waters throws much light on the composition 

 of the rocks through which they have passed. 



Dr. Qairdner, in his ' Natural History of Mineral and Thermal 

 Springs,' has endeavoured to generalise the connection between the 

 composition of mineral-waters and the rock formations from wliich 

 they flow : 



"1. The salts held in solution in mineral-waters have often no 

 connection with the acid, saline, or earthy matters which enter into 

 the composition of thu rocks which they traverse in their passage to 

 the surface of the earth, which seems to be the firt index that such 

 waters cannot derive their origin from these formations. 



"2. The mineral-waters of the primitive formations are almost all 

 thermal, and generally possess a very high temperature. Their pre- 

 dominant impregnation is usually sulphuretted hydrogen gas, free 

 carbonic acid gas, carbonate of soda, and in general salts with a base 

 of soda, silica, few calcareous salts, except the carbonate of lime in 

 some peculiar filiations, and but a small quantity of iron. 



" 3. The waters of the transition and older secondary formations 

 participate in those belonging to the primitive rocks. They are 

 generally of a lower temperature, though some of them are still very 

 hot; free carbonic acid is much less common, and sulphuretted 

 hydrogen is almost entirely absent Salts of soda still predominate, 

 but the carbonate is not so common, and the sulphate of lime is found 

 in the greater number of these waters. Silica exist* in two or three 

 examples. 



" 4. The waters of the newer secondary and tertiary formations are 

 as distinctly characterised as those of the primitive rocks, placed at 

 the other extremity of the series. They are all cold. Free carbonic 



