Bartey. | Mineral Waters. | o7 
sium and sodium. It has a tendency to increase the excretion 
of nitrogen. 
Magnesium has a characteristic action on the system. Ascar- 
bonate, it is useful in ‘‘ acid eructations and pyrosis, and in sick 
headaches, when accompanied by constipation. It is also of 
value in checking the formation of uric acid gravel and calculi.’’ 
This latter action is no doubt due to its alkaline character. 
As chlorid, magnesium is often found in saline waters and 
brines. It is useful to increase the flow of bile, and as a mild 
purgative. It is as a sulfate, however, that we are most fa- 
miliar with the action of magnesium. Like sodium sulfate, it 
‘promotes the process of endosmosis and exosmosis, and, by ab- 
stracting the watery elements of the blood, increases the intes- 
tinal secretions. ‘‘Hven if the quantity is small, it will tend 
to promote regularity of the bowels when taken continuously. 
The best results are observed in disordered conditions of the 
stomach, liver, and bowels, with concomitant symptoms of 
constipation. In sluggish states of the liver, characterized by 
a sallow countenance, yellowness of the conjunctiva, coating 
of the tongue, and hemorrhoids, the sulfated saline waters are 
speedily efficacious.”’ 
In eliminating the various chronic infections from the sys- 
tem-—-scrofulous, syphilitic, and malarial—as well as in ex- 
pelling lead, mercury, and other metallic poisons, they furnish 
us important and useful applications. For purgative effects, 
physicians recommend that the waters be taken on an empty 
stomach, before breakfast, and that a brisk walk in the open 
air follow the drinking of the water. These waters should not 
be taken when there is a chronic inflammatory condition of the 
stomach or intestines, or in case of general debility. 
It seems probable that the magnesium in water acts as an 
undissociated salt, as, although soluble, the magnesium ion is 
incapable of absorption into the blood. ‘‘ Magnesium” is prac- 
tically the only non-absorbable cation which can be used as a 
cathartic. Why certain ions should be capable of absorption, 
and others not, cannot be satisfactorily explained.’’ Magne- 
26. Text-book of Pharmacology, Sollman. 
