This is... a shockingly credulous take. Try not to be like this if your opinion ever matters.
Here's Pliny the Elder in full, Loeb translation (I'm including quite a bit more surrounding context than is relevant, just to make clear that this is everything relevant):
Moreover sheep, cattle, and draft animals are encouraged to pasture in particular by salt; the supply of milk is much more copious, and there is even a far more pleasing quality in the cheese. Therefore, Heaven knows, a civilized life is impossible without salt, and so necessary is this basic substance that its name is applied metaphorically even to intense mental pleasures. We call them sales (wit); all the humour of life, its supreme joyousness, and relaxation after toil, are expressed by this word more than by any other.
It has a place in magistracies also and on service abroad, from which comes the term "salary" (salt money); it had great importance among the men of old, as is clear from the name of the Salarian Way, since by it, according to agreement, salt was imported to the Sabines. King Ancus Marcius gave a largess to the people of 6,000 bushels of salt...
It's worth noting here that the glosses, "(wit)" and "(salt money)", are interpolations by the translator; Pliny doesn't gloss salarium at all. We can trace the gloss "salt money" for salarium all the way back to... the 1700s. And we should probably note that there it's conceived of as money that the soldier could use to buy salt, not as money that is made of salt.
So, there is no source relating the word "salary" to the concept of being paid in salt. There is a source relating the word "salary" to the concept of salt, and, if you really want to read into it, to the concept of Roman foreign service.
But there are many more problems with your comment. Pliny's authority as a historian has no relevance to this question. You'd want the opinion of a philologist, and you'd want it to be supported by something, which as you can see Pliny doesn't do.
> his claim about salt (which may simply have been common knowledge at the time) is no reason to doubt him as a historian.
And here you show an amazing ignorance of how reliable common knowledge of the origin of words is. The norm is that it's made up out of whole cloth. You can find gamers right now explaining that "meta" developed from the expression "most effective tactics available" or feminists explaining that "mankind" developed from a sexist preference for males over females. Neither idea has anything to do with reality.
All the amenities, in fact, of life, supreme hilarity, and relaxation from toil, can find no word in our language to characterize them better than this. Even in the very honours, too, that are bestowed upon successful warfare, salt plays its part, and from it, our word "salarium" is derived. That salt was held in high esteem by the ancients, is evident from the Salarian Way, so named from the fact that, by agreement, the Sabini carried all their salt by that road. King Ancus Martius gave six hundred modii of salt as a largess to the people, and was the first to establish salt-works.
The rewards of successful warfare, including salt, bestowed on soldiers. That is payment! King Ancus Martius also used salt as payment.
Here's Pliny the Elder in full, Loeb translation (I'm including quite a bit more surrounding context than is relevant, just to make clear that this is everything relevant):
Moreover sheep, cattle, and draft animals are encouraged to pasture in particular by salt; the supply of milk is much more copious, and there is even a far more pleasing quality in the cheese. Therefore, Heaven knows, a civilized life is impossible without salt, and so necessary is this basic substance that its name is applied metaphorically even to intense mental pleasures. We call them sales (wit); all the humour of life, its supreme joyousness, and relaxation after toil, are expressed by this word more than by any other.
It has a place in magistracies also and on service abroad, from which comes the term "salary" (salt money); it had great importance among the men of old, as is clear from the name of the Salarian Way, since by it, according to agreement, salt was imported to the Sabines. King Ancus Marcius gave a largess to the people of 6,000 bushels of salt...
https://www.loebclassics.com/view/pliny_elder-natural_histor...
It's worth noting here that the glosses, "(wit)" and "(salt money)", are interpolations by the translator; Pliny doesn't gloss salarium at all. We can trace the gloss "salt money" for salarium all the way back to... the 1700s. And we should probably note that there it's conceived of as money that the soldier could use to buy salt, not as money that is made of salt.
So, there is no source relating the word "salary" to the concept of being paid in salt. There is a source relating the word "salary" to the concept of salt, and, if you really want to read into it, to the concept of Roman foreign service.
But there are many more problems with your comment. Pliny's authority as a historian has no relevance to this question. You'd want the opinion of a philologist, and you'd want it to be supported by something, which as you can see Pliny doesn't do.
> his claim about salt (which may simply have been common knowledge at the time) is no reason to doubt him as a historian.
And here you show an amazing ignorance of how reliable common knowledge of the origin of words is. The norm is that it's made up out of whole cloth. You can find gamers right now explaining that "meta" developed from the expression "most effective tactics available" or feminists explaining that "mankind" developed from a sexist preference for males over females. Neither idea has anything to do with reality.