Furniture and Furnishings - Load bearing capabilities of antique jelly cupboard?

I've got a very old jelly cupboard, and I'm also a tropical fish enthusiast. The newest tank I'm getting is a 50-gallon, and I'd like to put it in my kitchen. The size of the tank would fit perfectly on top of my jelly cupboard, but I'm afraid to try it without some expert advice here. The cupboard is a cherished inheritance from my grandmother, an avid antique collector herself. The tank, when full, will weigh anywhere from 600 to 700 pounds! The weight would all be evenly distributed, but is this still too much to risk? :confused: Dimensions of the cupboard are about 41w x 18d x 44h. It's got 2 doors with 2 shelves inside, and 2 drawers above the doors. Any suggestions/advice welcome!

Don't do it
If the tank doesn't crush it imediately it will after a short time
The only safe way to support that tank is with a proper base, or a properly engineered/built structure

Perhaps a structure to hold the weight and protect the antique could support the tank just over the cupboard?
...still, I think I'd worry about water damage...Hmmm...maybe someone will come along with some ideas

Thanks, I guess that's the answer I was expecting. :( The tank comes with a sturdy stand made of 2x4's, but I was hoping to lose the stand and put it on the jelly cupboard -- I thought it would like very nice, and less floorspace taken. Oh well, no sense taking any chances. Thanks again.:)