This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Sea water contains, besides the common alimentary salt, a portion of bitter purging salt, similar to that of the foregoing waters, and which remains dissolved after the common salt has crystallized. After the purging salt also has been separated, there remains a small portion of a pungent saline liquor, which refuses to crystallize, and which appears to be a solu-tion of calcareous earth in the marine acid; The quantity of salt in different seas varies, according to the greater or less evaporation, and accession of fresh water, from about one fiftieth to near one twentieth of the weight of the water*
Sea water has lately come into esteem, against strumous swellings and obstructions of the glands, and different cutaneous soulnesses. Dr. Ruffel observes, that in the inflammatory state of glandular swellings it is improper; that where the tumor tends to suppuration, it does no good till the pus is discharged; that in other circumstances it is a remedy of great service, whether for resolving the tumor, or preventing a fresh fluxion upon the part; and that it is useful in disorders of the internal glandulous parts, as those of the mesentery, the liver, etc. as well as in those of the external. It has been given also in the true marine scurvy, and found to promote the cure; though incapable of conquering the disease without assistances from the vegetable kingdom.
The dose of sea water is from half a pint to a pint, which may be repeated every morning for some months. In these doses, it gently purges the belly, promotes also the other excretions, and somewhat warms and strengthens the habit: in large ones, it excites vomiting. In many cases, bathing in the water is advantageously joined; both as a general corroborant, and as a topical discutient and antiseptic.
This water, at first taking, is apt to occasion great drought; an inconvenience which is sel-dom much complained of after its use has been continued for some time, and which may in good measure be palliated by sleeping immediately after it is drank. It is apt likewise, in some constitutions, to produce immoderate heat; and even when used only externally, an uneasiness and itching of the skin: it is therefore to be refrained from in all inflammatory cases, and in habits prone to phlogofes. Among all the common saline bodies, to heat and to dry seem to be qualities peculiar to the marine salt.