rawing with a friction sufficient to separate the membrane without shredding, without eliciting over muchly the clear liquid which may spurt forth.<br /><br />Let us call the top right corner of the box Point A, the bottom right corner Point B, the left bottom corner Point C and the upper left corner Point D. Begin to pierce at Point A, proceed in turn to B, to C, ending at D, forming this a slit along the three edges. Arriving at Point D, withdraw the knife completely, wipe the blade with a sof