MEDICAMENTS AND LIFE. 220 
throws off constantly sweeten and cleanse the air. Travy- 
elers and physicians who have closely studied its physio- 
logical properties are persuaded that it might be introduced 
with advantage for giving salubrity to marshy countries 
where fever is endemic, by not merely altering the air, 
but also drying up the soil, and preventing the develop- 
ment in it of the aquatic vegetation from which miasma 
proceeds. 
These new medicaments of which we have spoken are 
all of them organic compcunds, that is to say, they are 
obtained more or less directly from vegetable or animal 
substances. ‘Therapeutics also makes use of quite a num- 
ber of mineral medical preparations. There are few among 
the latter whose introduction into practice is of recent date. 
Yet one of them that has come into use only within a few 
years has lately taken a very important place in the treat- 
ment of nervous disorders—we mean bromide of potassium. 
This salt, as to which physiologists had remarked its calm- 
ing action on the nerves and vessels, has lately been adopted 
by practitioners as a remedy for nervous affections, and 
particularly for epilepsy. Given in a dose of several 
grammes a day, it exerts the most striking sedative action 
upon that fearful nervous malady; if it does not cure it 
completely, it at least effects a long intermission between 
the attacks, and always quiets the shocks, the convulsions, 
and irritability of patients. Observations made on a great 
scale seven or eight years ago, in England and France, 
leave no doubt as to the reality of this result. Another 
mineral preparation in medicine, employed for a long time, 
arsenical acid, has become, through recent labors of Magi- 
tot, one of the most certain agents used in dental treat- 
ment; it possesses the singular property of inducing re- 
production of the ivory in teeth. - 
The facts we have here cited prove productive activity 
in the study of scientific therapeutics of late years, and 
