of scientific expression they are a misuse of language in fact they are nonsense. The word to wonder has of course a good sense which we all understand if it means to wonder at a certain state of things to wonder that such & such is the case. It has a good & clear sense to say that I wonder at some unusually dressed man as I have never seen before or at some strange sound etc. etc. It is also clear what it means to wonder at the existence of say a building which you thought had been pulled down long ago for here it has a meaning to say I did not think that this building still existed or to say that it does exist. On the other hand it's nonsense & not a proposition at all to say that colour & sound exist & for this reason it's nonsense to say that I wonder at their existence. Now the correct|right expression of what we mean when we say that colour & sound etc. exist is not a proposition at all but really the vocabulary