Forensic Chemistry

[ConfusedJew]

I agree with the others that this has already been provided repeatedly, but since you're asking, here's the most useful table for comparing numbers:
https://www.codohforum.com/viewtopic.php?t=463

Thanks.

What is this ridiculous attitude for? Do you think we haven't all argued with Jews before?

I wouldn't think that many, if any, would take it as seriously as I have been.

OK, so let me dig into this. I'm still a little confused with how to read that table, but you are welcome to correct me if I got anything wrong.

The core argument the table is making is “If the homicidal gas chambers were truly exposed to massive amounts of Zyklon B, then cyanide residues should be as high or higher than in the delousing chambers. But they’re not. Therefore, the gas chambers weren’t used for killing people.”

What the table actually shows:

1. Delousing chambers (e.g., BW 5a, BW 5b):
Cyanide levels: up to 13,500 mg/kg (very high).
Consistently high cyanide residues, both inside and near these chambers which was expected as Zyklon B was routinely and repeatedly used in large quantities over time.

2. Homicidal gas chambers (e.g., Crematoria II, III, I):
Cyanide levels: very low in most cases (often 0–1 mg/kg).
A few isolated samples with higher readings (e.g., Rudolf sample: 7.2 mg/kg).
This kind of measurement couldn't be dispositive because used Zyklon B in a fundamentally different way for a short exposure time, cleaned, ventilated, not reused as often.

3. Control samples:
Cyanide levels: <0.1 to ~1.7 mg/kg
These values help establish a baseline for what’s considered background or trace cyanide in similar materials.

Some issues with the argument:

1. The analysis focused on total cyanide without distinguishing between surface-bound vs. chemically stable compounds. Cyanide on surfaces can degrade over time, especially under acidic or wet conditions.

2. Leuchter and Rudolf chiseled chunks of brick and mortar from deep within the walls.
Samples were not taken from the surface, where most of the Zyklon B contact would occur. Cyanide compounds bind primarily to the surface. Going deep into masonry (especially up to 10 cm as Leuchter did) means you're testing material that was never exposed to Zyklon B.

3. Cyanide residues from the 1940s should still be measurable today (1980s–1990s). Cyanide compounds degrade over time, especially in moist environments (Auschwitz has a high water table), walls exposed to rain, snow, acidic conditions, cleaning, weathering, and reconstruction can further remove or dilute surface residues.

4. The earlier reports are less scientifically reliable because their methods had poor sensitivity and didn't account for detection limits. Better methods (like GC-MS) later did detect cyanide.

Fred Leuchter's analysis sent samples to a lab that used a colorimetric test for total cyanide. The detection limit was not precisely reported, but was likely in the range of 1–10 mg/kg. Several results were reported as "zero" or "no significant cyanide detected." The problem is the colorimetric test is not designed to detect very low residues, especially if surface layers (where cyanide would be) weren’t tested.

Germar Rudolf’s analysis claimed better methodology (and he was a chemist), but it still focused on total cyanide and Prussian Blue. He also failed to establish clear sensitivity thresholds. Some of his control samples had values like 0.1 mg/kg, suggesting his method could detect at least down to ~0.1 mg/kg, but probably not lower. The problem with his method was that it was never validated or peer-reviewed and results near the detection limit were not likely to be reliable.

Markiewicz et al. (1994, Kraków Institute) used gas chromatography–mass spectrometry (GC-MS), a high-sensitivity, modern forensic technique. The detection limit was much more sensitive at ~1 microgram per gram (i.e., 0.001 mg/kg or lower). They detected cyanide residues in homicidal gas chambers — even when Leuchter and Rudolf reported “none.” They also found higher residues in delousing chambers, but still positive results in gas chambers. Markiewicz demonstrated that cyanide compounds were present but below the detection limits of earlier methods. They also demonstrated the inadequacy of Leuchter and Rudolf’s methods to draw any firm conclusion.

Just because a sample shows “0.0 mg/kg” or “none detected” doesn’t mean no cyanide was ever present. It might just mean the cyanide is below the detection limit of the method used.

It's like trying to find bacteria using a magnifying glass. If you don’t see any, it doesn’t mean the bacteria aren’t there, just that your tool isn’t sensitive or powerful enough.

Dr. Jan Markiewicz and his team at the Institute of Forensic Research in Kraków (Poland) did test control samples in their 1994 study on cyanide residues at Auschwitz. Markiewicz's team tested both experimental samples from Crematoria I, II, III (homicidal gas chambers) and delousing chambers (e.g., BW 5a, 5b). They compared those results to Control samples taken from buildings never exposed to Zyklon B, such as the regular barracks, walls from administrative buildings, and foundations, etc. Cyanide was not detected in control samples. This confirmed that the method had a clear baseline (i.e., it could distinguish between exposed and unexposed materials). The method was able to detect even trace amounts of cyanide in samples exposed decades earlier, when present.

[ConfusedJew]

The problem here, is that you do not honor or accept corrections.

/shrug

You also don't ever retract.

I've been open about making mistakes and I've corrected at least some of them. I can be wrong about irrelevant things and it's not really worth much of a discussion, I just take the feedback and move forward with what I've learned. I'm investigating here so I will sometimes explore angles that I realize are wrong later on or may even just make a complete mistake with the use of AI. I admit that the AI is wrong occasionally although probably not as likely as many accuse it of being wrong.

I learn with AI probably 1,000x faster than I would without it even though it makes mistakes. The new model is out today which will hopefully have higher accuracy but I simply don't have the time to manually check everything. I am honest about that, if you hate it so much then you can ask me to leave but hopefully you will appreciate my honesty, even though I am regularly called a liar on here.

[HansHill]

Wetzelrad has sadly wasted his time and effort it seems.

Oh well.

[Stubble]

Wetzelrad has sadly wasted his time and effort it seems.

Oh well.

Just Wetzelrad? Some of your time may be missing as well Sir.

[Stubble]

The problem here, is that you do not honor or accept corrections.

/shrug

You also don't ever retract.

I've been open about making mistakes and I've corrected at least some of them. I can be wrong about irrelevant things and it's not really worth much of a discussion, I just take the feedback and move forward with what I've learned. I'm investigating here so I will sometimes explore angles that I realize are wrong later on or may even just make a complete mistake with the use of AI. I admit that the AI is wrong occasionally although probably not as likely as many accuse it of being wrong.

I learn with AI probably 1,000x faster than I would without it even though it makes mistakes. The new model is out today which will hopefully have higher accuracy but I simply don't have the time to manually check everything. I am honest about that, if you hate it so much then you can ask me to leave but hopefully you will appreciate my honesty, even though I am regularly called a liar on here.

That's as may be, but, what you can't do is consistently claim something that isn't true, after correction, cite documents that don't contain what is claimed and make things up about what historians have said, then when corrected, never retract.

That, that you can not do, yet you continue to.

[ConfusedJew]

Wetzelrad has sadly wasted his time and effort it seems.

Oh well.

It took him one second to point me in the direction of the chart with the different residue measurements. Do you dispute that the different tests had different sensitivity levels?

When you are detecting residual levels of a chemical that naturally degrades over time after 40-50 years of potential emission, test sensitivity matters a great deal.

Markiewicz et al performed controlled, systematic sampling from sheltered, well-documented locations to avoid contamination and weathering, focusing specifically on the thin surface layer where cyanide residues accumulate rather than pulverizing entire bricks, which dilutes trace evidence. By using sensitive and selective microdiffusion techniques, they accurately detected cyanide ions and distinguished them from interfering compounds. Their inclusion of appropriate negative controls—samples from living quarters that consistently showed no cyanide—demonstrated the specificity of their methods. Crucially, their work was conducted in the accredited Institute of Forensic Research in Kraków, ensuring adherence to quality control and proper chain-of-custody procedures. Their findings were transparently documented and subjected to peer review, lending credibility and reproducibility that the other studies lacked.

I don't think that either Rudolf or Leuchter necessarily tampered with their samples, but you can't be sure and that wasn't a risk for the Krakow Institute study due to their protocol.

[Stubble]

Wetzelrad has sadly wasted his time and effort it seems.

Oh well.

It took him one second to point me in the direction of the chart with the different residue measurements. Do you dispute that the different tests had different sensitivity levels?

When you are detecting residual levels of a chemical that naturally degrades over time after 40-50 years of potential emission, test sensitivity matters a great deal.

If you actually read Mr Hill's posts that are replies to you, you would have already seen it more than once.

Maybe this time it will stick and you will remember, I have my doubts.

[Wetzelrad]

I've written a response below, but it's rendered pointless by the fact that ConfusedJew dodged the issue. None of what he wrote was responsive to the issue, which had been laid out for him very neatly in laymen's terms.

3. Control samples:
Cyanide levels: <0.1 to ~1.7 mg/kg
These values help establish a baseline for what’s considered background or trace cyanide in similar materials.

Yes, this is the core of the issue. If the background level of cyanide ranges to as high as 9.6 mg/kg, then how can the lower levels found in the hypothesized gas chambers be considered proof of executions there? They can't.

1. The analysis focused on total cyanide without distinguishing between surface-bound vs. chemically stable compounds. Cyanide on surfaces can degrade over time, especially under acidic or wet conditions.

Not to make this an argument of semantics, but "surface bound" seems to be terminology invented by your AI. I think we don't actually know definitively which cyanide compounds were detected by Markiewicz or how stable they are. We only know that he chose his method to exclude iron cyanides, whereas the revisionists chose to measure total cyanides. Therefore the two categories are non-iron cyanides and total cyanides.

2. Leuchter and Rudolf chiseled chunks of brick and mortar from deep within the walls.
Samples were not taken from the surface, where most of the Zyklon B contact would occur. Cyanide compounds bind primarily to the surface. Going deep into masonry (especially up to 10 cm as Leuchter did) means you're testing material that was never exposed to Zyklon B.

A) Rudolf 1993 actually specified his sampling depth. Markiewicz 1994 did not, which means only Rudolf's data can be used to make informed statements about sample depth.

B) Rudolf took some shallow samples and some deeper samples. As examples, R1 and R15a were both from a depth of 0-3 mm, and R7 was from a depth of 0-1 cm. Even R3, from a supposed gas chamber, was at a depth of 1-1.5 cm, yet it still had a positive cyanide reading of 6.7 mg/kg. So the inner material definitely was exposed to cyanide.

C) There are several buildings where HCN from Zyklon did in fact penetrate deep into the walls, even reaching the exterior side.

D) This is arguing against yourself. If cyanide would be higher at the surface, it would be higher at the surface in the delousing chambers, potentially strengthening the revisionist case even more.

E) Do you have a source for Leuchter going to 10 cm depth? That sounds made up.

4. The earlier reports are less scientifically reliable because their methods had poor sensitivity and didn't account for detection limits. Better methods (like GC-MS) later did detect cyanide.

You have no idea what you're talking about. Markiewicz was one of the earlier reports, so you're saying he was not scientifically reliable? And since he alone did not account for detection limits, that also means he was not reliable? Okay, great.

Fred Leuchter's analysis sent samples to a lab that used a colorimetric test for total cyanide. The detection limit was not precisely reported, but was likely in the range of 1–10 mg/kg. Several results were reported as "zero" or "no significant cyanide detected." The problem is the colorimetric test is not designed to detect very low residues, especially if surface layers (where cyanide would be) weren’t tested.

Here your AI is trying to reword the revisionist argument that Markiewicz neglected detection limits in his paper. This is strictly a revisionist argument. It becomes nonsensical when reversed.

The detection limit in Leuchter's case was reported. Roth, the lab manager, reported it at 1 mg/kg. If it had been 10 mg/kg then all but one of Leuchter's samples would be zeros or NDs.

Further, if you say that colorimetry is not sensitive enough, then how can you be sure of its sensitivity when Markiewicz used it?

Germar Rudolf’s analysis claimed better methodology (and he was a chemist), but it still focused on total cyanide and Prussian Blue. He also failed to establish clear sensitivity thresholds. Some of his control samples had values like 0.1 mg/kg, suggesting his method could detect at least down to ~0.1 mg/kg, but probably not lower. The problem with his method was that it was never validated or peer-reviewed and results near the detection limit were not likely to be reliable.

False information and backwards logic. You may as well claim that no cyanide study has ever been valid.

Markiewicz et al. (1994, Kraków Institute) used gas chromatography–mass spectrometry (GC-MS), a high-sensitivity, modern forensic technique. The detection limit was much more sensitive at ~1 microgram per gram (i.e., 0.001 mg/kg or lower). They detected cyanide residues in homicidal gas chambers — even when Leuchter and Rudolf reported “none.” They also found higher residues in delousing chambers, but still positive results in gas chambers. Markiewicz demonstrated that cyanide compounds were present but below the detection limits of earlier methods. They also demonstrated the inadequacy of Leuchter and Rudolf’s methods to draw any firm conclusion.

To my understanding, all of the labs that measured cyanide used spectrometry. Markiewicz is the only one who totally ignored detection limits. His results merely confirmed Leuchter's.

Just because a sample shows “0.0 mg/kg” or “none detected” doesn’t mean no cyanide was ever present. It might just mean the cyanide is below the detection limit of the method used.

It's like trying to find bacteria using a magnifying glass. If you don’t see any, it doesn’t mean the bacteria aren’t there, just that your tool isn’t sensitive or powerful enough.

Tests have detection limits for a reason. When measurements approach the detection limit, false positives become more common. This is even explained at the top of Epstein 1947. If you think it's acceptable to ignore detection limits, then what's stopping me from claiming that all 0.0s actually include traces of cyanide?

All of this sidesteps the problem we were just discussing.

[ConfusedJew]

My contention was that cyanide traces in the control samples were roughly equal to those in the supposed gas chambers. You offered "contamination from weathering, renovation, or debris" and adjacency as explanations for that. If you find these to be sufficient explanations for trace cyanides in the control samples, then surely they are also sufficient explanations for trace cyanides in the supposed gas chambers.

It seems like you didn't understand my explanation, but if your test is not sensitive to properly measure cyanide residues, then you will find that the same levels between residue and controls. The test wasn't powerful or accurate enough which is why test results were unreliable at that level.

To the contrary, Leuchter, Rudolf, and Mattogno all took control samples that came back positive for trace cyanides. In all three cases their total cyanide content was actually higher than what Markiewicz measured by his method in any of his samples.

They didn't come back positive. They came back uncertain meaning that they couldn't differentiate between actual residue and noise.

You know nothing about the chain of custody in any of these investigations, but chain of custody is not even in dispute here so it's totally irrelevant.

Chain of custody was not carefully guarded in the deniers experiments while make them less trustworthy. That wasn't an issue with Markiewicz. Both Rudolf and Leuchter took the samples illegally. With that kind of behavior, why wouldn't they fake the test results? I'm not arguing that they did, but it definitely reduces the trustworthiness of those studies compared to the one that followed forensic standards.

You can keep asking your AI to say this as many times as you like, but nearby buildings have in fact been found to have cyanide readings of 1.2, 1.3, and 9.6 mg/kg.

I already explained this. On the chart, it explicitly says at those levels, the result is "uncertain" meaning that you can't say whether or not its positive or negative.

[ConfusedJew]

I've written a response below, but it's rendered pointless by the fact that ConfusedJew dodged the issue. None of what he wrote was responsive to the issue, which had been laid out for him very neatly in laymen's terms.

Yes, this is the core of the issue. If the background level of cyanide ranges to as high as 9.6 mg/kg, then how can the lower levels found in the hypothesized gas chambers be considered proof of executions there? They can't.

That is right. You simply cannot trust that specific test to detect accurate levels of cyanide at that threshold. Meaning the test is quite literally useless to test at low amounts.

Not to make this an argument of semantics, but "surface bound" seems to be terminology invented by your AI. I think we don't actually know definitively which cyanide compounds were detected by Markiewicz or how stable they are. We only know that he chose his method to exclude iron cyanides, whereas the revisionists chose to measure total cyanides. Therefore the two categories are non-iron cyanides and total cyanides.

Surface bound is another way of describing "adsorbed" cyanide – attached to a surface via weak forces (van der Waals, hydrogen bonding, or ionic attraction). "Absorbed" means that the substance penetrates into the material as opposed to just the surface.

Markiewicz tested for all cyanides not bound to iron. He excluded the stable iron–cyanide complexes such as hexacyanoferrates (Fe(CN)₆³⁻ / Fe(CN)₆⁴⁻).

That means the cyanides he could detect would fall into the categories of Free cyanide (CN⁻ and HCN) and Weak acid dissociable (WAD) cyanides (cyanides complexed with metals like zinc, cadmium, copper, silver, nickel). He may have also detected some strongly bound non-iron complexes if they could be broken under his chosen conditions.

Since he deliberately ruled out iron cyanides, the most environmentally persistent, whatever was detected was likely to be more labile, meaning more reactive or more prone to environmental breakdown. It is true though that we can't say exactly which compounds without a speciation analysis.

A) Rudolf 1993 actually specified his sampling depth. Markiewicz 1994 did not, which means only Rudolf's data can be used to make informed statements about sample depth.

B) Rudolf took some shallow samples and some deeper samples. As examples, R1 and R15a were both from a depth of 0-3 mm, and R7 was from a depth of 0-1 cm. Even R3, from a supposed gas chamber, was at a depth of 1-1.5 cm, yet it still had a positive cyanide reading of 6.7 mg/kg. So the inner material definitely was exposed to cyanide.

Not necessarily. Based on that test, according to the chart, a reading below 10 mg/kg is "uncertain". Not accurate to say that it was "definitely" exposed to cyanide. But even if it were, I think that would be supportive of the idea that cyanide was used for homicidal purposes.

C) There are several buildings where HCN from Zyklon did in fact penetrate deep into the walls, even reaching the exterior side.

D) This is arguing against yourself. If cyanide would be higher at the surface, it would be higher at the surface in the delousing chambers, potentially strengthening the revisionist case even more.

Yes, there is no question that cyanide was used in the delousing chambers according to any of those sampling methods. That does not mean that it didn't exist in the homicidal chambers.

E) Do you have a source for Leuchter going to 10 cm depth? That sounds made up.

This is worth a bit of a clarification. Fred Leuchter did not specify or control the sampling depth when collecting his brick, mortar, and concrete fragments from the gas chambers. He simply chiseled off pieces—fist-sized chunks—of indeterminate thickness from walls, ceilings, and floors. Dr. James Roth, the lab manager who processed these samples, testified that cyanide residues would likely have penetrated only about 10 micrometers—roughly a tenth of a human hair—into these surfaces. But because the samples Leuchter brought were of unknown thickness, Roth ended up grinding entire fragments into powder. This meant the cyanide-containing surface layer was mixed with a much larger volume of brick or mortar, diluting the results substantially.

https://www.errolmorris.com/film/mrd_transcript.html

Here's the direct quote from Roth, "You have to look at what happens to cyanide when it reacts with a wall. Where does it go? How far does it go? Cyanide is a surface reaction. It's probably not going to penetrate more than 10 microns. Human hair is 100 microns in diameter. Crush this sample up, I have just diluted that sample 10,000; 100,000 times. If you're going to go look for it, you're going to look on the surface only. There's no reason to go deep, because it's not going to be there. Which was the exposed surface? I didn't even have any idea. That's like analyzing paint on a wall by analyzing the timber that's behind it. If they go in with blinders on, they will see what they want to see. What was he really trying to do? What was he trying to prove?"

You have no idea what you're talking about. Markiewicz was one of the earlier reports, so you're saying he was not scientifically reliable? And since he alone did not account for detection limits, that also means he was not reliable? Okay, great.

You are misunderstanding what I wrote. Unlike Markiewicz, the earlier reports did not have sufficiently reliable detection limits to detect the residual amounts of cyanide that you would have expected to find in a homicidal gas chambers.

Here your AI is trying to reword the revisionist argument that Markiewicz neglected detection limits in his paper. This is strictly a revisionist argument. It becomes nonsensical when reversed.

No, it's not. I'm not sure what you are trying to say exactly. Markiewicz specifically used a more highly powered test so it's more reliable at the lower limits whereas the previous revisionist tests were not.

The detection limit in Leuchter's case was reported. Roth, the lab manager, reported it at 1 mg/kg. If it had been 10 mg/kg then all but one of Leuchter's samples would be zeros or NDs.

This is different than what was on HansHill's chart and his original lab reports were never released, but if you take him at face value, the way he prepared the samples, such as grinding entire brick fragments rather than isolating surface layers, would have dilute cyanide concentrations far below detection limits, making non-detects less meaningful.

Further, if you say that colorimetry is not sensitive enough, then how can you be sure of its sensitivity when Markiewicz used it?

This might have been a mistake with AI. Let me look into this and I'll clarify.

False information and backwards logic. You may as well claim that no cyanide study has ever been valid.

Why do you say that?

To my understanding, all of the labs that measured cyanide used spectrometry. Markiewicz is the only one who totally ignored detection limits. His results merely confirmed Leuchter's.

I think this is wrong but it is late so I will look into this tomorrow.

Tests have detection limits for a reason. When measurements approach the detection limit, false positives become more common. This is even explained at the top of Epstein 1947. If you think it's acceptable to ignore detection limits, then what's stopping me from claiming that all 0.0s actually include traces of cyanide?

All tests have limits. It is possible to say that every test measurement might have missed a tiny amount of residue that the test was not sensitive to pick up. But the reverse isn't true.

All of this sidesteps the problem we were just discussing.

I don't think so.

[HansHill]

.

This is all slop. All of it.

Re "tampering". Not sure where you are going with this other than to muddy the waters even more. It is not credibly asserted anywhere that Rudolf's samples are "tampered with", in fact Green stands on business that Rudolf's samples are in line with expected values given the tests performed. I told you about 10 pages ago that nobody from your side actually quibbles with Rudolf's numbers.

Likewise Revisionists don't accuse Markiewicz as tampering his figures. Instead, we focus on the things he attested to in his methodology - 1 being that he omitted long-term cyanides, and 2 that he doesn't understand the processes involved in iron cyanide reactions. This is what we focus on, which we can stand over, and point to. We don't need to accuse him of fudging his numbers because there is nothing in his numbers, because he didn't look for the murder weapon.

You will continue to fail to realize any of this, and I look forward to seeing you repeat your mindless slop tomorrow.

[HansHill]

Re the CJ vs Wetzelrad exchanges:

Wetzelrad has thoroughly and soundly outperformed CJ. I only just want to make one observation, even though W has mentioned it adequately:

Depth profiling: The only study to apply depth profiling is the Rudolf study. This is yet one more reason as to why the Rudolf study is by far and away more robust than that of Markiewicz. Aside from depth profiling, Rudolf also measured for iron content, and ensured in-built redundancy by having his samples analyzed separately by two independent institutes (double blind).

You are arguing against yourself on matter of methodology, this has already been explained multiple times, and you will fail to realize and address all this until you actually read what we are saying.

Re AI - it is baffling and hilarious that you think a 130 page book or 2 hour video is too much time investment, which would actually get you somewhere, VS a 4 month series of mindless AI slopthreads which go absolutely nowhere.

This is why we call you dishonest. This is why we laugh at you.

[ConfusedJew]

This is all slop. All of it.

Re "tampering". Not sure where you are going with this other than to muddy the waters even more. It is not credibly asserted anywhere that Rudolf's samples are "tampered with".

Rudolf literally illegally took samples from the UNESCO World Heritage site...

I'll be generous and just "assume" that the samples were not intentionally tampered with beyond that initial crime.

[ConfusedJew]

Re AI - it is baffling and hilarious that you think a 130 page book or 2 hour video is too much time investment, which would actually get you somewhere, VS a 4 month series of mindless AI slopthreads which go absolutely nowhere.

I've been given thousands of pages to read and many multiple hour long videos to read.

You can refuse to defend your position and just insult and criticize but that shows you don't have a response. Can you defend the Rudolf and Leuchter Report as being as sensitive and credible as the Markiewicz report? No, I don't think so which is why you are dodging.

You can call me dishonest all you want, it's clear that I am not being dishonest.

[ConfusedJew]

Depth profiling: The only study to apply depth profiling is the Rudolf study. This is yet one more reason as to why the Rudolf study is by far and away more robust than that of Markiewicz. Aside from depth profiling, Rudolf also measured for iron content, and ensured in-built redundancy by having his samples analyzed separately by two independent institutes (double blind).

You are missing the point. Iron content doesn't add value to the study which is why Markiewicz didn't bother to test for it.

Why do you think "depth profiling" adds any value to the study or makes it more reliable? It does the opposite by diluting the samples. Roth mentioned this in his testimony.

The complaint about the Rudolf test is not that the labs tampered with the analysis, it's that they weren't sensitive enough and that they were diluted.

What you describe is not double blind. Now you are clearly out of your depth. A double-blind study is a research method in which neither the participants nor the researchers know who is receiving the treatment or intervention and who is receiving a placebo or control. This design minimizes bias, as it prevents expectations from influencing the results.

Rudolf knew what he was sampling even if the lab analysts didn't. Double blind isn't really a concept that adequately applies to chemistry studies though.