Get a tray(like) thing, much wider than the pot. Fill it with stones and water, but make sure the water is always lower than the stones. Put the pot on top of it and you now have a proper humidity tray. Offices are terrible for anything but philodendron and Sanseveria! Give it more light for up to 16 hours a day if you can (a full spectrum, high wattage fluorescent fixture would be ideal, but they generally only come in 4' lengths). Also ideal would be that fixture hanging only 5-6 inches above the tree. That's how much light they can use. Misting, unless it's a prof. system, is fairly useless, BTW. Allow the top 1/2" to dry between waterings, let the water warm up for a few minutes if it's cold, and when the tree is doing better, switch out at least half of its mix to pure grit (small aquarium gravel will do until you learn more) and mix it all together. Don't ever let the pot bottom near the tray's water or roots will rot.

It is very possible that the tree was 'scorched' as you said. If it was sitting too close to that window, if it was a big enough one...it's May and the sun is getting more intense in your part of the world.

And I'll tell you why I think this...

Right now I'm having trouble with my large Water Jasmine (2) and another small leaved tree. We've had a very hot spring, most days the temps have been close to or at 100 deg. here. Last year these trees were under 20% shade and did well, the shade got blown away by the typhoon we had.

Last month the new growth came to a dead stop and the leaves began to turn a uniform brown. On a smaller tree this would look like it was all happening at once (which yours probably is?) on my large WJ the foliage pads were at least 8" by 10" and layered so it took a little time.

As the top leaves burned away the lower ones followed shortly. The trees are still green under however, they are completly dormant and almost bare of foliage.

I would say just keep the soil a little damp, not even moist and let the tree recover. It may take a while, up to a few weeks. The smaller tree just sat there and did nothing for almost 3 weeks and is now beginning to leaf out again.

At first I thought that the person watering them, while I was gone, had doused them with hot water out of the hose...until...my big one out front started to do the same thing.

Bob

Thanks for the advice! I am tempted to defoliate the tree in the hopes that it might help encourage new growth. Is this a good idea or should I just let it be?

Let it be, but up the humidity - it's important, more so I think in your climate than worrying about scorching for this tree. Scorching may be a factor in the tropics, but I wouldn't think it's that worrisome where you live.