Question

Until Antoine Lavoisier proved otherwise in the eighteenth century, many scientists had believed that combustion released phlogiston, an imaginary substance whose properties were not fully understood.

1) many scientists had believed that combustion released phlogiston, an imaginary substance whose properties were not fully understood
2) many scientists believed that phlogiston was an imaginary substance released by combustion and its properties were not fully understood
3) phlogiston was an imaginary substance whose properties were not fully understood and which many scientists had believed was released by combustion
4) phlogiston, an imaginary substance whose properties were not fully understood, was believed by scientists to be released by combustion
5) many scientists had believed that phlogiston was released by combustion and was an imaginary substance whose properties were not fully understood

My Doubt:

I encountered this question in CAT 1. The Original Answer is 1 but I marked 5. I was successfully able to eliminate 2,3, and 4, but was stuck between 1 and 5. I eliminated 1 because it says "phlogiston, an imaginary substance whose properties were not fully understood". Choice 1 basically means that "many scientists had believed that combustion released phlogiston" only. If a phrase "an imaginary substance whose properties were not fully understood" comes after "phlogiston" and is seperated by a comma, it essentially means that the information in necessary but not critical to the understanding of the sentence (this is there in OG). However, applying OG's Logical Prediction method, the sentence clearly intends to say that many scientists not only believed that combustion released phlogiston, but also believed that it was an imaginary substance whose properties were not fully understood.

Thus, I feel that the answer should be 5, which correctly suggests that "many scientists had believed that phlogiston was released... and was an imaginary..." "until Antoine Lavoisier proved otherwise in the eighteenth century".

Please advise.

nah.

in fact, choice (e) is self-contradictory. if the scientists believed that phlogiston was actually being released, then they clearly didn't think that it was an imaginary substance.
conversely, if they thought that phlogiston was imaginary, that wolud preclude their thinking it could be released from a real-life, non-imaginary chemical reaction.

choice (a), which gives a definition of "phlogiston" as an appositive, makes more sense - because, exactly as you've said, the main point of the sentence is that the scientists believed that combustion released phlogiston.
but you better believe that those boys thought phlogiston was real.

--

incidentally, i don't like the wording of the sentence; since phlogiston really is imaginary, it makes no sense to write about its "properties" (because, as an imaginary substance, it doesn't have any properties).
i'll see if i can get that part of the question fixed.
but the appositive choice (a) is the best choice.

Thanks Ron,

Your explanation is bang on target. However, it came a bit too late. I took my GMAT on Sept 2, 2008 and scored well.

Just wanted to thank you guys for the near testing experience of your CAT exams though I didn't get challenging questions by the time I started with the 5th and the 6th CAT exam. This could be because I had already exhausted the 700-800 level questions in the earlier tests. I suggest that you widen your pool of 700-800 questions or else by the time students take the 5th and 6th CAT, they encounter only 500-600 and 600-700 level questions and so score high on your tests. The resulting fake confidence before the actual GMAT may be disastrous for them. Nevertheless, the first four Manhattan CAT exams were really helpful for my preparation.

Keep up the good work!! :-)))))

Pooja

Thanks Pooja,

Congratulations on doing well. And regarding your suggestion: we are working on it!

Thanks again,

_________________
Emily Sledge
Instructor
ManhattanGMAT

Hi Emily,

Why is B wrong. I knocked out 5 and 1 because "had believed" seems wrong to me.

Please help.

Xins

Xins, the past perfect "had believed" is ideal because two things happen in the past, but at different times:

(1) Many scientists believed that combustion released phlogiston (prior to #2)
(2) Antoine Lavoisier proved otherwise (in the 18th cent.)

Past perfect is used for the earlier past action, while simple past tense is used for the more recent past action. Choice (B) uses the simple past for both verbs, incorrectly implying that they were simultaneous. I suppose the "until" clarifies the intended timeline, but the verbs should indicate the order correctly, too.

Additional problems with (B):
--"was an imaginary substance released by combustion" is unnecessarily in passive voice.
--the construction "and its properties were not fully understood" is incorrectly parallel with "phlogiston was released by combustion" rather than subordinate to it, as in the original sentence; this also creates ambiguity around the pronoun "its" which could refer to either combustion or phlogiston.

_________________
Emily Sledge
Instructor
ManhattanGMAT

In terms of just parallelism which one is correct ?

many scientists had believed that phlogiston was released by combustion and was a toxic substance whose properties were not fully understood
or
many scientists had believed that phlogiston was released by combustion and that it was a toxic substance whose properties were not fully understood

I have slightly altered the sentence. In most cases I have seen form 2. scientists believed in two things ..that and that ..

But I need more light on this!

Hi kramacha1979,

BOTH have good parallelism and are therefore correct.

Look at parallelism this way--there is a shared sentence opener that has two alternate, parallel endings. The two endings should each make sense when read following the shared sentence beginning.

...many scientists had believed that phlogiston:
(1) was released by combustion and
(2) was a toxic substance whose properties were not fully understood

...many scientists had believed:
(1) that phlogiston was released by combustion
AND
(2) that it (phlogiston) was a toxic substance whose properties were not fully understood

The first example is slightly preferable, as it is shorter. However, the wordiness/repetition of "that phlogiston" in the second example is acceptable: it's grammatically correct, and fosters clarity by emphasizing the intended parallelism.

_________________
Emily Sledge
Instructor
ManhattanGMAT

EMILY,


Doesnt "an imaginary substance....." seem to modify the entire first clause
I have a problem here understanding as to when to call a part of the sentnce appositive and when to take it as modifier
Pls explain ( to cut short isnt "an imaiginary a modifier modifyig the former part of the sentence )

PLS HELP

Until Antoine Lavoisier proved otherwise in the eighteenth century, many scientists had believed that combustion released phlogiston, an imaginary substance whose properties were not fully understood.

Hello Emily,

In one of your posts you metioned that "until clarifies the intended timeline, but the verbs should indicate the order correctly, too", so if everything else is equal what will be the correct construct for this sentence. Proved is the simple past of prove and believed is the simple past of believed.

Please explain.

Thanks,

Vineet

I was thinking along the same lines, which made choose (D). I also took (A) to mean that combustion was actually releasing something (as if by own will), while (D) foused on the byproduct, phlogiston.

If someone could clarify the simple past, I'd really appreciate it!

this sort of thing depends on context. it's usually pretty easy to figure out the context, but you should be aware that these appositive-type modifiers can modify EITHER the preceding noun OR the entire preceding clause/phrase, depending on exactly what that context is.

in the first choice, it's obvious that "an imaginary substance..." is meant to refer to phlogiston. so this is ok.
judging by your post, it seems that you probably understand this context - but that you just didn't know that appositive-type modifiers have this sort of flexibility. so now you understand.

--

by the way, USUALLY (but not always), the following hold:
* if the appositive type noun is concrete (such as "a substance"), then it will usually refer to the preceding noun.
* if the appsitive type noun is abstract (such as, say, "findings" or "a shortcoming"), then it will usually refer to the entire preceding clause. see #59 and #79 in the purple verbal supplement if you want examples.

_________________
Being well-dressed gives a feeling of inward tranquillity [that] religion is powerless to bestow.
C.F. Forbes

thanks Ron,

it makes absolutely clear

glad it helped.

_________________
Being well-dressed gives a feeling of inward tranquillity [that] religion is powerless to bestow.
C.F. Forbes

Is it correct to use whose in option 1? Shouldn't who / whose refer to the scientista?

phlogiston, an imaginary substance whose properties were not fully understood