64 



CHEMISTRY. 



With liy. 

 drogrn. 



times in bulk of it. Its specific gravity is 2.61. It 

 is composed of two parts in volume of chloric gas, 

 and one of oxygen gas. When heated, it is decom- 

 posed, nd light and heat are produced. 



2. Chlorine combines very readily with hydrogen, 

 and forms the very important compound called mu- 

 rialtc arid. When the gases, each as dry ts possible, 

 are mixed together in equal .bulks, and the mixture 

 exposed to the light of the sun, inflammation takes 

 place, the two gases disappear, and a quantity of 

 muriatic acid gas is formed nearly equal to them in 

 bulk. Now, as the specific gravity of muriatic acid 

 gas is almost exactly the mean of the specific gra- 

 vity of hydrogen and chloric gas, it is inferred that it 

 is a compound of equal bulks of these gases. There- 

 fore muriatic acid is composed by weight of 



97.24 chlorine, 

 2.76 hydrogeoi 



100.00 



or of one part of hydrogen and about 35 of chlorine. 

 But if we suppose, with Mr Davy, that the propor- 

 tion of hydrogen exceeds that of chloric gas in bulk, 

 we may consider muriatic acid as composed of one 

 part hydrogen, and 33 of chlorine. 



Muriatic acid may be obtained by putting some 

 common salt in a small glass retort, pouring over it 

 sulphuric acid, and receiving the product over mer- 



CU J7- 



Muriatic acid gas is invisible, and possesses the me- 

 chanical properties of common air. Its specific gra- 

 vity is 1.278, that of air being 1.000. Its smell is 

 pungent and peculiar, and when mixed with air it 

 forms a visible smoke, owing to its great avidity for 

 moisture. 



It does not support combustion, nor can it be 

 breathed by animals. When a lighted taper is plun- 

 ged into it, it goes out with a green coloured flame. 



Water, when brought into contact with this gas, ab- 

 sorbs it with great rapidity, and the whole disappears. 

 Water absorbs 515 times its bulk of th:-. gas, and six 

 cubic inches of water by this absorption are convert- 

 ed into nine. The affinity between tins gas and wa- 

 ter are very gre-t. 



Water saturated with this gas is known by the name 

 of liquid muriatic add. It has been long kn.-w:i, and 

 is very much employed by chemists. When pure, it 

 is transparent and colourless : but it very often has a 

 greenish yellow colour, owing to the presence of 

 iron or of some other impurity. It has the smell of 

 muriatic acid gas, and smokes when exposed to the 

 air. Its specific gravity is never greater than 1.203, 

 and seldom exceeds 1.196; and when strongest, never 

 contains more than one- fourth of its weight of acid: 

 the rest is water. 



The following Table gives us the strength and 

 boiling point of muriatic acid of various densities. 

 It is from the experiments of Kirwan and Dalton. 



of 

 Chenmrrv 



Muriatic acid combines with various bases, and 

 forms a class of salts called muriates. 



3. As far as is known at present, chlorine do.s With 

 not combine with carbon ; b'lt it unites with carbonic carbon, 

 oxide, and forms an acid gas much heavier than any 

 other gaseous body yet discovered, and called phos- 



gen gas. 



4. When a current of chloric gas is made to past With 

 over flowers ot sulphur, a combination gradually flower* of 

 take* place, the sulphur changes its colour, and a * ul P nur - 

 fine red liquid is formed more than twice the weight 



of the sulphur employed. To this compound, ori- 

 ginally discovered by Dr Thomson, Mr Davy has 

 given the name of sulphvrane. 



Sulphurane is a liquid of a fine red colour between 

 scarlet and crimson. By transmitted light it appears 

 green. Its specific gravity is 1.623. It smokes 

 very much, is very volatile, and has a smell similar to 

 that of sea plants. Its taste is strongly acid, hot 

 and bitter, affecting the throat with a painful tick- 

 ling. It dissolves phosphorus readily, and forms an 

 amber coloured liquid, which at last catches fire when 

 left to spontaneous evaporation. When dropt into nitric 

 acid it effervesces with considerable violence. With 

 alcohol it becomes hot, and the smell of ether be- 

 comes perceptible. When dropt into water, it is gra- 

 dually decomposed. Flocks of sulphur separate, and 

 the water contains sulphuric and muriatic acids in so- 

 lution. With ammoniacal gas it forms a solid red 

 compound, which is decomposed and converted into 

 sulphate and muriate of ammonia and sulphur by ihe 

 action of water. Such are the properties of this re- 

 markable compound as far as they have been hitherto 

 ascertained. We are not acquainted with the propor- 

 tion of its constituents. 



4. When phosphorus is introduced into chloric With 

 gas it takes fire spontaneously, and burns with a low ph<wpb 

 white flame, and at the same time melts. Two sub- ru * 

 stances are formed, one a clear liquid, the other a 

 dry white matter which sublimes during the com- 

 bustion. To this compound Mr Davy has given the 

 same of phosphoranc. 



Pliosphorane appears to possess some acid quali- 

 ties, at least it combines with ammonia, and forms a 

 white insoluble tasteless powder, very similar to silica 

 ih many of its properties. When phosphorane is di- 



