170 



DEFINITION OF TERMS. 



Boil in a covered vessel down to 12 parts 

 Then filter, and add sugar, - 24 " 

 Boil to a sirupy consistence. 



The above is from the Paris Codex, 

 and contains about sixteen grains of ipe- 

 cac, to the ounce, or about two and a half 

 grains of emetia. 



To get clear of the ^um and starch 

 which make a sirup soon spoil, other re- 

 cipes recommend alcoholic maceration, 

 and subsequent evaporation in making 

 the sirup, to dissipate the spirit. 



As a better process than either of the 

 above mentioned, I would suggest the fol- 

 lowing, being an improvementupon them : 



Take of ipecac, finely bruised, two 

 ounces; place in a small displacement-fil- 

 ter, and, to extract the soluble active prin- 

 ciples, pass over it a weak alcohol, (15) 

 lb. iss. Evaporate by a gentle heat to 

 four ounces, and add four pints of simple 

 sirup; then boil for a while, that the sirup 

 may be of proper consistence. 



There are several compound sirups of 

 ipecac, combining its virtues with those 

 of senega, bark, and opium. 



Sirup of ipecacuanha is employed to 

 stimulate the mucous membrane of the 

 bronchise in certain pulmonary affections, 

 and from its frequent use would seem to 

 form an indispensable ingredient in 

 French and German prescriptions for 

 this purpose. — Jour. Phar. 



Iron, prope.rlies of. It has a styptic 

 taste, and emits a smell when rubbed. 

 Its specific gravity varies from 7.6 to 7.8. 

 It is attracted by the magnet or load- 

 stone, and is itself the substance which 

 constitutes the load-slone. But when 

 iron is perfectly pure, it retains the mag- 

 netic virtue a short time. It is mallea- 

 ble in every temperature, and its mallea- 

 bility increases in proportion as the tem- 

 perature augments; but it cannot be ham- 

 mered out nearly so thin as gold or silver, 

 or even copper. Its ductility, however, 

 is more perfect; for it may be drawn out 

 into wire as fine, at least, ns the human 

 hair. Its tenacity is such, that an iron 

 wire 0.078 of an inch in diameter, is ca- 

 pable of supporting 549.25 lbs. avoirdu- 

 pois without breaking. When heated to 

 about 158° Wedgewood, it melts. This 

 temperature being nearly the highest to 

 which it can be raised, it has been im- 



possible to ascertain the point at which 

 this melted metal begins to boil and to 

 evaporate. Neither has the form of its 

 crystals been examined; but it is well 

 known that the texture of iron is fibrous; 

 that is, it appears when broken to be 

 composed of a number of fibres or strings, 

 bundled together. 



When exposed to the air, its surface is 

 soon tarnished, and it is gradually chang- 

 ed into a brown or yellow powder, well 

 known under the name of rust; this 

 change takes place more rapidly if the 

 atmosphere is moist. It is occasioned 

 by the gradual combination of the iron 

 with the oxygen of the atmosphere, for 

 which it has a very strong affinity. 



When iron filings are kept in water, 

 provided the temperature is not under 

 70°, they are gradually converted into a 

 black powder, while a quantity of hydro- 

 gen gas is emitted. This is occasioned 

 by the slow decomposition of the water. 

 The iron combines with its oxygen, while 

 the hydrogen makes its escape under the 

 form of a gas. If the steam of water is 

 made to pass through a red-hot iron tube, 

 it is decomposed instantly. The oxygen 

 combines with the iron, and the hydro- 

 gen gas passes through the tube, and may 

 be collected in proper vessels. This is 

 one of the easiest methods of procuring 

 pure hydrogen gas. — These facts are suffi- 

 cient to show that iron has a strong affi- 

 nity for oxygen, since it is capable of 

 taking it from air and water. It is capa- 

 ble also of taking fire, and burning with 

 great rapidity. Twist a small iron wire 

 into the form of a cork-screw, by rolling 

 it round a cylinder; fix one end of it into 

 a cork, and attach to the other a small bit 

 of cotton thread dipt in melted tallow. 

 Set fire to the cotton, and plunge it while 

 burning into ajar filled with oxygen gas. 

 The wire catches fire from the cotton, 

 and burns with great brilliancy, emitting 

 very vivid sparks in all directions. For 

 this very splendid experiment we are in- 

 debted to Dr. Ingenhouz. During this 

 combustion the iron combines with oxy- 

 gen, and is converted into an oxide. 



INIr. Proust has proved that there are 

 only two oxides of iron; and the protox- 

 ide has usually a black color, but the per- 

 oxide is red. 



