LESSONS IN < HK.Mi 



four ounces ; orange-peel dried, three ounces ; 

 .Ini.-luiii ; aatTron. two drachms ; ooobi- 



i,-i! \< i; proof spirit, twu piutt ; maoorate for 



tin." 



!" i-ithor of these preparation* may bo 

 I IWN niUi.-r too 

 u of the pui 



H M N.O :H ' ' - bitter prin- 



the yellow bark, mixed with cinchona. 



in thi* Hubritaueu by making both sulphates, 



i :i!|..wni'_' thn salts to cryHtalliho; the Hulphate of 



{itiniii, I'.-.iiu much less soluble than that of cinchona, crys- 

 tallises out tir>t. 



The characteristic tost of quinia U : when freshly prepared 



chlorine watr is poured into a solution of this alkali, a green 



colour is produced whon a few drops of ammonia are added. 



ad of ammonia, finely powdered potassium ferrocyanide 



be added, a deep red colour is produced. 



line itself is always procured from the solution of its 

 s .j]ph:ite, by dcH'omiHxsing the salt by tho addition of ammonia, 

 whereupon it falls in white flakes. 



(Juinin-.- .s'l/'yi/m/c i- tho salt by which quinine is employed in 

 medicine. It appears crystallised in ooicular prisms, which 

 are very light. It is hut sparingly soluble in water, but is 

 freely dissolved if a little sulphuric acid be present. It is a 

 celebrated medicine in fever and remittent diseases, such as 

 ; besides, it possesses great tonic properties. For house- 

 hold use a shilling's worth of sulphate of quinine may bo put 

 into a wine-bottle of water, and five or six drops of sulphuric 

 acid will cause the Bait to bo dissolved ; a wine-glass of this 

 solution once a day is a very efficient tonic. 



It will be noticed that it has a peculiar action on light ; 

 that the clear and colourless solution, when light is permittod 

 to pass through it, becomes a pale blue. 



in. This celebrated drug is the juice (oiror) of the 

 poppy. It is chiefly prepared in Turkey, Persia, India, and 

 China ; yet the poppy is grown, to a great extent, in the south 

 of Europe, for the sake of the oil which can bo expressed from 

 its seed. The mode of obtaining opium is this : After the 

 flowers have fallen, the head of the poppy is cut horizontally, 

 but not sufficiently deep to reach the internal cavity of the 

 shell ; a milky juice immediately flows out and collects in tears 

 on the edges of the out ; in this state the field is left for twenty- 

 four hours, and for the next two days tho opium is collected by 

 :i it off with blunt knives. It is then placed in earthen- 

 ware pots, and finally dried in the sun, wrapped in poppy or 

 tobacco leaves, and sold. Tho process is somewhat varied in 

 Asia, by beating up the exuded juice with saliva ; the seeds of 

 the plants thus treated are not injured, and are sown for tho 

 next year's crop. 



Opium is of greatly complicated construction; it contains 

 twelve ingredients, the most important being 



Morphia (C, 7 H 19 NO.,) which is a base, and is found in opium 

 in combination with meconic and sulphuric acids. It is to this 

 body that the sedative effects of opium are duo. It is procured 

 as short rectangular prisms ; it is but slightly soluble in cold 

 water, very soluble in alcohol, but insoluble in other or chloro- 

 form. Nitric acid turns the crystals orange ; a mixture of 

 nitric: and sulphuric acids colours morphia green. 



The best test is afforded by tho action of neutral ferric 

 chloride, which renders a solution of any salt of morphia a 

 dark blue. 



Codeia (Cj,H z ,TCO.j,H.,O). The proportion of this nitrrce base 



in opium is very small ; its action is powerfully narcotic. Being 



soluble in ether, it is readily separated from morphia ; moreover, 



none of the tests by which morphia is recognised are common 



t\vn s-ubstrniees. 



Narcotiri'' (G tt H. a NO r ,H 1 O). This body does not possess 

 auch basic properties as those preceding, as might be antici- 

 pated from the larger quantity of oxygon which enters into its 

 composition. It is an active poison, though not so virulent as 

 morphia. Being soluble in chloroform it is easily separated 

 from morphia, and with a mixture of sulphuric and nitric acids, 

 gives a blood-red colour. 



ALKALOIDS FROM THE 8TBTCHNOS TRIBE OF PLANTS. 



Strychnia (C 21 H 22 N.,Oj) is ono of the most powerful of 

 vegetable bases ; it can displace many metallic oxides from 



their combinations ; it occurs in tho seed* of the titrgchnot nu* 

 I'omtca, a tree which grows on the coast of Corotnandel and 

 parts of the East Indies. 



It is a most deadly poison, producing tetanus ; its action 

 seems directed upon the motor tract of the spinal cord. If 

 any part of this cord be destroyed, the convulsion* ooso in 

 that part of tii- l>ody whose nerve* take their rise in the de- 

 stroyed part. 



It is dissolved by GOO times its weight of cold water, anJ 

 such is its intense bitter, that it can bo recognised by the taste 

 when dissolved in 600,000 times iti weight 



There U no antidote for this poison ; tho stomach mnst be 

 emptied of its contents as soon at possible, by emetic* and the 

 stomach-pump. In a short time tho muscle* become rigid, 

 spasms sot in, and the patient dies of suffocation. 



To discover the presence of strychnia in any organic Analysis, 

 tho liquid is saturated with potah ; this liberates the organic 

 bases. By agitating chloroform, the strychnia is dissolved out. 

 Before evaporating this solution, the base crystallines, and may 

 bo discovered by the microscope ; or if sulphuric acid be poured 

 upon it with a fragment of potamic dichromate, a beautiful 

 violet tint appears which fades into a rose colour ; with the 

 chloride of gold a blue colour is produced. 



Brucia (C., 3 H t8 N,0 4 ,4H,0). This alkali is present in nni 

 vomica in larger quantity than strychnia ; it is also found in the 

 bark of the Brucea antidysenterica, which does not contain 

 strychnia. 



It is distinguished from strychnia by the bright scarlet colour 

 passing into yellow, whic i its salts give with nitric acid. Its 

 poisonous qualities are not so marked as those of strychnia. 



ALKALOIDS OF THE BEVERAGES. 



Theine or Caffeine (C g H 10 N t O t ,H,O). It is more than re- 

 markable that in all parts of the world men have discovered, 

 and converted into a beverage, a vegetable product containing 

 this active principle. Tea contains an much as 4 per cent., 

 whilst in coffee it seldom exceeds 1 per cant. 



Theine is procured by making an infusion of tea with alcohol. 

 The tannin this solution contains is precipitated by means of 

 plumbic acetate ; the precipitate is separated by fil '.ration, the 

 excess of lead is separated by passing sulphuretted hydrogen 

 The free acetic acid is now neutralised by the addition of 

 potash, and on evaporation the theine crystallises out in long 

 silky needles. 



This substance has the remarkable property of retarding the 

 wear of the tissue of the body ; this is the reason why old 

 people live so much upon tea. The best tea and coffee is sold to 

 tho artisans in London, who find that they can continue to 

 work on tea, whereas a heavy meal would materially affect their 

 labour. 



Theobromine (C 7 H 8 N 4 0.,) is a like alkaloid, present in cocoa. 

 This group is of great chemical interest, from the numerous 

 compounds it yields when acted upon by various re-agents. 



ESSENTIAL OILS. 



In these oils resides the scent which characterises most 

 plants ; they are chiefly composed of carbon and hydrogen, and 

 aro very volatile. They are not unlike fixed oils, but have 

 not a greasy feel, and are readily soluble in alcohol or ether. 

 Somo of these oils are not existing in the plant, but are pro- 

 duced by a species of fermentation ; this is the case with the 

 oil of almonds and the oil of mustard. 



Some of the oils are procured by simple expression, others 

 tho larger class are obtained by suspending the plant in a net 

 in boiling water, and distilling tha vapour. Tho water which 

 thus comes over with the essential oil is the fragrant distilled 

 water of the apothecary. 



To separate tho essence from this water, salt is added, and 

 the oil rises to the surface. These oila are generally yellow, 

 and whan exposed to the air absorb oxygen and become resinous 

 bodies. 



Oil of Turpentine (C, H ia ). If turpentine, which exudes 

 from tho various species of pines, be distilled with water, it 

 yields about one-fourth its weight of oil of turpentine, leaving 

 rt:-;in in tho still. This is sold in England as camphine ; it is s 

 great solvent for sulphur, phosphorus, and caoutchouc. 



There are many essential oils allied with oil of turpentine ; 

 the most important are 



