I know of at least one SSPX chapel where there is a gluten free host given out at communion time to a person or persons. How can they do this if they believe a miracle happens.

Why so melodramatic? How do you KNOW that they use a gluten free Host?  

At The Consecration The Host and Wine only have the APPEARANCE OF BREAD AND WINE . The elements have been changed INTO THE BODY ,BLOOD, SOUL AND DIVINITY OF OUR LORD. THINK OF THE MIRACLE OF LANCIANO, That happens everyday at Mass. Has anyone tested to see after The CONSECRATION if there was gluten present ? I doubt they have.

The Miracle happened at The Consecration, no other Miracle is needed !

You understand that after the Consecration, the appearances of bread remain. Do you realize that means they act like bread to all physical measurements and activities, including chemistry?

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Apparently cosmas has not learned what substance vs. accidents means.
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I know someone who refuses to use the word "accident" in this way because he says, "An accident is something that shouldn't happen."
Maybe we should come up with a new word for it, but for now, we have what we have.
St. Thomas Aquinas is the first one to distinguish these terms and to bring natural human thinking into the realm of Church theology in this matter.
His work rose to the papacy, and his Lauda Sion Salvatorem became the Sequence at Mass on the Feast of Corpus Christi as a result.
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At the consecration of the host and altar wine, their substance is changed into the substance of Our Lord Jesus, and this is a matter of faith.
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But the accidents of the host and wine remain, unchanged.
     The host still looks, smells, weighs, tests, appears, acts and reacts (chemically) the same as an unconsecrated host does.
     And the wine still has alcohol, if you drink too much consecrated wine you'll get drunk, it weighs the same, looks the same and acts the same.
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There can never be any measurable difference in the consecrated host and wine, in the normal state of affairs.
     That's not to say that no difference ever happens, but when there is a difference, that is called a miracle because it can't be explained by science.
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Therefore, if there were gluten in the wheat before the consecration, the same gluten would be there after the consecration, and it would act the same.
     The same gluten intolerant person would be just as intolerant toward the consecrated host as to a non-consecrated host of the same lot number.
     That is to say, under normal circuмstances that's what happens.
     And the miracle of transubstantiation takes place under normal circuмstances.
     When we say "Eucharistic miracle" we are not talking about a normally valid consecration and the expected effects of that normal scene.
     Eucharistic miracles are outside normal circuмstances, when visible, testable changes are seen taking place in the host and/or wine.
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If a gluten intolerant person does NOT react to a consecrated host with gluten in it, THAT would be out of the ordinary, which could happen.
     It could happen but it probably won't happen, and it would be highly presumptuous to expect it to happen, so we shouldn't do that.
     However, God can do what He wants any time He wants, and He might reward someone with simple faith who just believes he'll be okay.
     There have been recorded cases of a person living for years without taking any food except for the host in Holy Communion every day.
     That is not proof that anyone can do that any time without fear or fact of starving to death.
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Therefore, when we hear of someone who is gluten intolerant not having any reaction to gluten-containing hosts, that is not the end of the story.
     We should not conclude that proves once and for all that the consecration removes the effects of the gluten.
     Maybe it does in one chapel or with one priest, or when one particular person receives it.
     But that might be a quiet miracle taking place because it is not something that we ought to proclaim will always be the case.

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At The Consecration the Host and Wine only have the APPEARANCE OF BREAD AND WINE. The elements have been changed INTO THE BODY, BLOOD, SOUL AND DIVINITY OF OUR LORD. THINK OF THE MIRACLE OF LANCIANO, That happens everyday at Mass. Has anyone tested to see after The CONSECRATION if there was gluten present? I doubt they have.

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This post is rife with confusion and misunderstanding based on presumption and lack of study or research or comprehension.
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One thing at a time:
At The Consecration the Host and Wine only have the APPEARANCE OF BREAD AND WINE.   --- Not true.
While it IS true that the host and wine have the appearance of bread and wine, that is not ALL they have: it's not a matter of "only".
In this case the word "appearance" is a one-word abbreviation for the full topic of what they have.
They have everything that is LIKE appearance too, such as smell, heft, color, size, taste, feel -- that is, everything sensible to man.
But it's more than that, because accidents include everything that instruments designed by man can be used to detect.
Things such as weight, atomic structure, radioactivity, x-ray pictures, non-visible light spectrum analysis, density, hardness, brittleness, and so on.
Any possible chemical reaction is also included in the accidents of a material object.
So it is more correct to say the host and wine continue to have the same ACCIDENTS of bread and wine (instead of "appearance").
But the word "accidents" is not normally used in our culture in this sense so uninformed people (like cosmas here) would be ignorant of that.
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The elements have been changed INTO THE BODY, BLOOD, SOUL AND DIVINITY OF OUR LORD.   --- Well, not so fast.
The host and wine have been changed into the body, blood, soul and divinity of Our Lord, yes, but they don't look that way.
Remember, they retain the appearance of bread and wine.
But appearance needs to be replaced with accidents, so THEY RETAIN THE ACCIDENTS OF BREAD AND WINE.
To say "the elements have been changed" is vague, and could lead to misunderstanding that the physical atomic structure and molecules
     of the bread and wine are suddenly altered somehow, which, if they were, an electron microscope would be able to SEE the difference.
     Remember, no device made by man will ever be able to detect the change that has happened in the consecrated host and wine.
The infallibly defined Catholic dogma that their substance has become the Second Person of the Blessed Trinity is a matter of divine faith.
This faith is what we receive at Holy Baptism, and it is not something that can be attained by human effort without God's grace.
So count it a miracle of grace that you believe in trasubstantiation, because Lutherans, for example, do not.
Perhaps that means that Lutherans might not have a valid baptism, but that's another topic.
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THINK OF THE MIRACLE OF LANCIANO, That happens everyday at Mass.  ---  Well, not really.
The miracle of Lanciano happened hundreds of years ago and while there have been similar eucharistic miracles since, it's not the norm.
Every valid consecration effects the same transubstantiation that occurred at Lanciano, but there, changes in the accidents were sensible.
Normally there are no changes in the accidents and no such changes are sensible to man, whether by his 5 senses or by some fancy machine.
Normally there are no changes in the appearances or the molecular structure or the chemical potential of the consecrated material bread and wine.
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Has anyone tested to see after The CONSECRATION if there was gluten present? I doubt they have.  ---  Many tests have been done.
There were tiny samples taken from the Laciano eucharistic miracle and they were sent to chemical labs to test for what it appeared to be.
There have been samples taken from other such eucharistic miracles and sent to forensic labs, cutting-edge technicians and doctors have reviewed.
What they have found was the fibers of human heart muscle tissue were microscopically intertwined with the fibers of the host wheat.
Wheat host fibers are fibers BECAUSE they are being held in that shape by the gluten in their structure.
Without gluten the wheat has no such fibers.
Gluten free wheat crumbles like mush and cannot hold the shape of anything, including the shape of a host, unless something is substituted.
There might be some other material that could take the place of gluten to keep gluten free wheat in the shape of a host.
So when a priest holds the host up like at the elevation or when he's distributing Communion, the hosts have their shape because of gluten.
Wondering whether there is still gluten or not is a moot point. Of course there is still gluten.
There continues to be gluten even in the bread portions of eucharistic miracles.

At the SSPX chapel in San Antonio, a couple years ago, one man received the Precious Blood during Mass on Sunday. He had some kind of allergy or intolerance. The priest would administer to him from a small chalice kept in the tabernacle. 

It really was quite a spectacle. It's a shame Trad priests don't have more time, to say more Masses for each area per week, so that individuals like this could have their special needs met at a Mass with less attendance.

That presumes that such catering to special needs is legitimate. I honestly don't know, not having studied this in a professional manner.

I do know that we had a parishioner who was gluten intolerant, but she never got to receive Communion. Not from a gluten free or low-gluten host, and not from the chalice. This was under Bp. Zendejas. 

I just want to say "THANKYOU " FOR ENLIGHTENING ME on this subject. There's much food for thought. i'm going to do some more research on this situation myself. Thanks again for the input !