Dolæus upon the cure of the gout by milk-diet / To which is prefixed, an essay upon diet

by Johann Doläus; William Stephens

In the next Place we are to enquire into the Properties of Milk, and to find out whence it hath such wonderful Powers in asswaging and curing this Distemper. There are some Authors, especially the Followers of Sylvius, who according to the chymical Scheme would have Milk produced from the Blood in the following Manner; Chyle, which is of a white Colour, may be turned into Blood by the Help of Alcalies; and again the Blood may be reduced to Chyle by the Help of Acids. Junkius, in his Chymistry, hath noted the Experiments when Milk is to be turned into Blood: Take a Pound of new Milk, and mix with it an Ounce of reverberated Salt of Tartar in a large Vessel; in a Quarter of an Hour the Mixture shall turn into a Blood red Colour, several Fibres swimming at Top like Cream. When the Blood is to be turned into Milk, take any Quantity of the foregoing Mixture, and drop in some Vinegar, and it shall immediately re-assume the Form of Milk. In the first Experiment they alledge, that the crude Sulphur of the Chyle is by the Alkali exalted into a red Sulphur; in the second, the exalting Alkali is depressed by the Acid, whence the Sulphur returns to its original white Colour. Junkius is very justly doubtful of the Application of this Experiment; how the crude Sulphur of the Chyle, as they call it, should in so short a Time be changed into Blood by Alkalies, and the Blood, exalted by so many Circulations, be again changed into Milk by Acids, seems very strange. It requires a good deal of Time to change the Chyle into perfect Blood, and the Blood again into Milk, notwithstanding that Women who have no Milk find it in their Breasts soon after Childbirth.

SECT. 2.

In order to be fully satisfied of the Nature of Milk, it is necessary to examine into the Manner of its Generation: It seems reasonable to imagine, that the Chyle, once received into the lacteal Vessels, and at length mixed with the Blood, is never again let forth with the same Appearance; only in Women at the Time of Childbirth, when it is plentifully separated, through the Ramifications of the Arteries, by the conglomerate Glands of the Breast. There is evidently a great Agreement between the Milk and the Chyle, in as much as the Chyle consists of a watry, limpid and gelatinous Fluid, with oily or fat Globules swimming therein. These Globules are pellucid, and differ both in Size and Figure; the Reason of its Whiteness is to be imputed to this: The oily Globules are mixed with the watry ones, in such Manner that several very smooth Globules are formed, which reflecting the Rays of Light in right Lines, occasion a white Colour; the same thing is observable in making Emulsions with oily Seeds, or upon mixing resinous Essences with Water, or mixing Oyl and Water, and shaking them well together; in these Cases, the watry and oily Particles, being thoroughly mixed, occasion such a Superficies as reflects a white Colour. Bolin, and several Authors have proved, that the Milk is no other than oily or fat Lymph or Chyle, brought with the Blood to the Breasts, and there deposited in the milky Cells. Berger hath very well explained the Manner of its Separation in the Breasts. The whole Substance of the Breasts, in Women giving Suck, is made up of various Ramifications of Arteries, from the thoracick and mamillary Arteries, which terminate in oval Cells, or glandulary Follicles; from hence the Breast swells with many milky Vessels, terminating in the Nipple; through these the more oily and chylous Parts of the Blood are derived from the Glands, where it is not only separated, and received, but gathered and preserved, while the remaining Mass of the Blood is returned by the Veins and Lymphaticks. These milky Rivulets, after breaking very small from the Ramifications of the Arteries, flow together into several larger Trunks, which in their Progress are united by Insertions of their Parts, in some Places more dilated, in others streightned, from several Cells and Cisterns, where the Milk is gathered and preserved, so as always to have a sufficient Quantity for the Nourishment of the Infant. Lastly, as the Chyle is separated from the Mass of the Food in the Bowels, not by any Precipitation, but by Percolation only; and as in the making of Emulsions, the oily Seeds communicate an oily Milkiness to the Water, and is separated from the grosser Parts by the Sieve, without the Intervention of any precipitating Medicine, so the chylous Juice is separated in the Bowels by gentle Pressure or the Peristaltick Motion, and strained through the Orifices of the lacteal Vessels, to be thence thrown into the Mass of the Blood. In like manner, the Milk is barely separated, by straining the milky Particles from the Blood, through the small Ramifications of the Arteries in the Glands of the Breasts.

SECT. 3.

Nuck hath sometime ago demonstrated, that these conglomerate Glands are a Bundle of small Vessels; that their excretory Ducts are Continuations of the arterial Ramifications, and that these Glands owe their Origin to the smallest Branches of the Arteries: These Arteries, which enter the glandular Substance of the Breasts, are imperceptible to the naked Eye, and discoverable only by injecting a very fine Tincture (which Nuck tells us is known to very few Anatomists) into the Artery; this may be so far propelled, as to render the milky Ducts conspicuous. For the better Discovery of this Matter, Nuck instituted another Experiment equally curious and useful; having met a Nipple full of excretory Ducts, he pressed it, and the Breast adjoining, so as to empty all its Contents, and having pitched upon one of the widest Ducts, he injected Mercury so artificially, that he immediately observed the milky Ducts spread like Branchings of Trees; some Part of the Mercury was carried so far as to enter the Arteries, whence the milky Vessels were continued.

SECT. 4.

Hence it follows, that these milky Ducts are destitute of Valves, otherwise the Mercury and the injected Liquors would have been obstructed in their Passage. It is indeed observable, that these Canals are in some Places streighter and narrower than in others, so as to give some kind of Obstacle to the Injection; this is not to be imputed to Valves, but to some kind of Hardness peculiar to the Substance of the Glands, by which the milky Vessels are compressed. From hence appears the immediate Inosculation of the milky Ducts, with the small Ramifications of the Arteries, of which these Glands are composed; so that the arterial Blood propels and deposits its chylous and serous Particles by gentle Pressure and Impulse in the milky Ducts, without other Mechanism than bare Straining and Secretion. For the further and more exact Description of these Ducts, see Nuck’s Adenographia.

SECT. 5.

It remains now to examine, of what kind of Particles chiefly Milk is composed; which appear to be these three: The first is a fat, butyraceous, oily, and sulphureous Substance. The second is cheesy, earthy, chalky, and saline. The third is the Vehicle of these, viz. serous, which is watry, with a Mixture of nitrous Salts. But these Parts don’t hold the same Proportion in the Milk of all Animals; Cows Milk is most used in Food, it is thick and fat, and contains more Butter than the Milk of other Animals; upon which account it nourishes more, and is more agreeable to the human Body. Ews Milk hath more earthy and cheesy Particles; Goats Milk is in a Mean between these two, only that its Serum contains more of a nitrous Salt; whence Etmuller conjectures, that it hath all the Virtues of Whey made from Cows Milk, especially in Heats and scorbutick Cases. Asses Milk is of all the thinnest, next to human; the Milk of other Animals, as not so usually brought into Food, I forbear to describe.