I'll tell you how old at the end of the post.
The issue was whether Russia hemp was a "like article" to Manila hemp, in the MFN context. Here's one side of the argument:
The turning point in the treaty will be found in the meaning of the words, "the like article," and we must accept the ordinary technical sense of like, or the sense in which it is invariably used when employed in the language of treaties, and as defined by Webster: "Equal in quantity, quality, or degree; exactly corresponding." Again: "That which is equal or similar to another; the counterpart; an exact resemblance; a copy." Neither party could have attached any other meaning to the words than such as is here given. Any other interpretation would unfix the boundaries of every treaty in existence, and throw, everything into dispute and confusion. The words do not mean almost the like articles, nor nearly the like articles, but like articles, or absolutely the same articles. No matter if the word "like," in some exceptional cases, is used in qualified sense, as nearly equal. Here it is used as absolutely "like," or the same, and nothing less nor more. ..
...
Russia hemp and Manila hemp are quite unlike in appearance, Russia hemp being of a dull yellowish-green color, while Manila hemp is much brighter and lighter, or almost a cream color. The latter is rather sharp and stiff to the touch, and the former comparatively soft and more yielding. Botanically they are distinct, and differ totally. Manila hemp is found only in equatorial regions. Russia hemp is cultivated in more northern latitudes. Manila is from the leaves of plants, chiefly the musa textalis, a plant allied to the banana, and known by the local name of abuca, a shrub or tree, both wild and cultivated, growing abundantly in the Indian Archipelago. The fiber is the petioles of the leaves, and sometimes the inner layers of the smallest fibers are used for very fine fabrics, but only the larger layers for cordage. Russia hemp is a plant of the genus cannobis sativa, whose fibrous skin or bark is utilized like that of flax, and is used, not only for cables and cordage, but for common table·cloths, huckaback towels, and especially for sail cloth, though, in some measure, superseded by iron cables and cotton sail cloth. It will be seen that the two articles are no more alike or akin in the vegetable kingdom than are foxes and dogs, or horses and asses, in the animal kingdom, and nothing but some kin of the latter could ever confound them commercially.
This side's conclusion: The "articles" are not "like" and there is no discrimination against Russia hemp here.
Here's the other side:
2. The present report of the majority gives a construction to the term "like articles" so restricted that it would, if adopted and acted upon by foreign nations baving this kind of treaties with us, reduce such treaties to a practical nullity. Dictionary meanings of terms used in public instruments are not the only or the principal means of determining the sense. The great object of the provision must be regarded as the principal guide to the meaning of the terms. If the term "like" means in this treaty, as is contended in the report of the majority, absolutely identical, a case of absolute identity in any botanical production, the growth of one country, soil, and climate, could never arise, and the treaty would have no meaning. ... While we do not admit that the lexicographical meaning of the English word "like," and of the French word "meme," is confined to things that are identically the same, it is quite obvious that eyen if the words of the treaty had been "the same articles," there would still be an equally strong necessity for interpreting the words by the great purpose of the provision. ... [We are satisfied with a definition of "like articles" that means] articles which, being known in trade and commerce by the same name, are so far alike that one can come into injurious competition with another, for any of the purposes of trade or manutacturing, so as to work an unfavorable discrimination against the eountry with which the treaty subsists.
3. It is not necessary that the unfavorable discrimination should appear to have been designed, in order to give rise to a complaint of infraction of the treaty. The presumption in furtherance of good faith should be and always is, unless the contrary expressly appear in some reason or reasons of state, or from some express declaration, that the unfavorable discrimination was inadvertent and unintentional. Whether there is, in truth, a practical discrimination against the interests of the nation with whom we have formed the treaty, is always a question of fact. In the present case, the affidavits, which are treated with so much levity in the report, clearly establish the facts that "Russia hemp" and "Manila hemp", are articles that are both known in trade and commerce as hemps; that for some purposes they may be and are used in the same kind of manufacture; and that, consequently, to put a higher duty on Russia hemp, when it is "the produce of Russia," than is put upon Manila hemp, is an injurious discrimination against a "production of Russia," in favor of the production of some other country. This is all that needs to be shown in order to establish that these two things are "Iike articles," in the sense of such a treaty.
So for this side, it's the discriminatory effect on products that are in competition with each other that is key. Intent can also play a role. On the facts here, this side would have found that discrimination against Russia hemp exists.
Where is all this from? An 1872 report from the U.S. Senate finance committee. Here is the document: http://www.worldtradelaw.net/hemp_likeness_case.pdf It's a complicated set of facts, but briefly, the U.S. was charging a higher duty on Russia hemp than Manila hemp, despite a treaty with Russia that guaranteed MFN treatment. The importers of the Russia hemp wanted a refund on the higher duties they had been paying. There were some judicial proceedings on the issue as well, but I guess they didn't go favorably for the importers, who then turned to Congress. The first side noted above is the majority report of the Senate finance committee, the second side is the minority report.
It's amazing how the arguments from 140 years ago continue on today.
For those with an interest and some free time, there are some other good issues in there as well. What are the implications of Congress acting in violation of a treaty? Do individuals acquire personal rights under treaties?
This wasn't something I was looking for. I stumbled on it while researching something else. But it turned out to be quite interesting!