So much of the tissues as are necessary for the experiments to be performed are taken, and to them is added at most five times their quantity of water. If any difficulty arises in the boiling, which may be traced to the insufficient quantity of tissue used, then more tissue is added, the excess of the organ being immediately put back into the bottle that contains the rest, in case it may be wanted later on. If the organ is left lying about for any time it becomes infected. An organ should never be boiled without being previously tested. It should not show any places that contain blood.
Further, the tissue must be shredded into small particles before it is boiled. It would be a great mistake to boil the tissues in large pieces and to use them later in the form of little pieces, for it might often happen that inside the big pieces products were enclosed which diffuse and react with ninhydrin, and they would not be noticed because they have not reached the outside. If, for instance, a lentil is boiled as a whole, the water does not readily show any ninhydrin reaction, but as soon as the lentil is broken up and boiled an intense reaction is observed. In the process of boiling the outer part coagulates, and thus tightly encloses the inner contents. Exactly the same thing may happen with other tissues. Therefore, before the experiment, the organ must be boiled in the same way as it is intended to be used, i.e., in a shredded form.
