Page:Defensive Ferments of the Animal Organism (3rd edition).djvu/220

 Three series of experiments were conducted with the same sera, and with equal quantities of these. In the first experiment the organ was = 0, i.e., it was absolutely free from substances which could be boiled out and filtered, and which, under the strictest conditions, would produce a coloration with ninhydrin. In every case we had to add to the quantity of substances emanating from serum alone, and passed into the dialysate, 0 gr. of these compounds. Then, in the experiment serum + organ, the ninhydrin reaction obviously remains negative.

For the second experiment an organ was taken, which passed over to the boiled water just a trace of reacting substances. We will assume that it contained 0.10 gr. of these compounds. This quantity is added to that which the serum gives off, and we have the positive reaction of Cases 6 and 8. The limital value, 1, has been exceeded. Thus, by means of a simple addition, a positive reaction has been obtained and, in consequence, two errors in diagnosis. The third column shows us how the ninhydrin reaction results, when we use an organ prepared in a still more imperfect manner.

Exactly the same position is reached, if the dialysate