5 5 6 THE POPULAR SCIENCE MONTHLY. 



of semicircular incisions are made in the capsule of the poppy, and 

 the juice which exudes is carefully gathered. This juice, on being 

 dried in the sun, becomes of a dark color, thickens, and forms a brown, 

 firm paste : this is opium. Laudanum is a solution of opium in alcohol 

 and water. Both opium and laudanum are to be regarded as a mix- 

 ture of several similar but not identical substances. Since the time of 

 Derosne (1804) and Robiquet (181*7), who first isolated narcotine and 

 morphine, chemists have very carefully investigated the different 

 chemical compounds occurring in opium. Thus they have discovered 

 codeine, narceine, theba'ine, papaverine, and other substances, all of 

 them bases, i. e., bodies that unite with acids to form crystallizable 

 salts. 



These bases do not all affect in the same way the organic func- 

 tions. Thus, narcotine possesses very little or no soporific power : 

 two grammes of it can be injected without perceptible effect, while a 

 centigramme of morphine is quite sufficient to produce therapeutic and 

 physiological results. Theba'ine does not cause sleep, and in animals 

 produces convulsions like those caused by strychnine, while morphine 

 in the same dose produces deep comatose sleep. Another curious 

 thing about these opium alkaloids is, that they do not act alike on 

 man and animals, as has been demonstrated by Claude Bernard. 

 Man is specially sensitive to the action of morphine, while theba'ine 

 is almost without effect upon his nervous system : animals, on the 

 other hand, feel the effects of morphine only when it is given in large 

 doses, while theba'ine is for them a violent poison. So, too, with bel- 

 ladonna, and atropine, its active principle, they are a deadly poison 

 for man, but almost without effect on rabbits : the dose of atropine 

 that would suffice to kill ten men would hardly be enough to kill one 

 rabbit. The difference is not so great with respect to morphine, yet 

 morphine specially affects man ; hence in this article we will consider 

 only this one opium alkaloid. 



When, in " Le Malade imaginaire," honest Argan is asked why 

 opium causes sleep, his artless reply is, " Quia habet proprietatem 

 dormitivam." Nowadays we are not content with this kind of ex- 

 planation, and some authors have sought for the " dormitive prop- 

 erty " of opium in the state of the cerebral circulation ; and, though 

 the true cause has not yet been certainly established, still it is some- 

 thing that research has been made. 



It is not yet positively decided whether opium produces anaemia 

 or whether it produces congestion of the brain ; indeed, we know lit- 

 tle more than did Argan, namely, that it sets one asleep. This sleep, 

 however, is in some respects different from ordinary sleep. From 

 thirty to sixty minutes after taking opium one feels a slight excita- 

 tion ; there is a general feeling of buoyancy and contentment, soon 

 followed by drowsiness and a state of reverie rather than of dream- 

 ing. There is a pleasurable feeling of abandon, and an agreeable 



