PROTEIN COAGULATION AND ITS REVERSAL : THE IDENTITY OF NORMAL HEMOGLOBIN WITH THE HEMOGLOBIN PREPARED BY THE REVERSAL OF COAGULATION, AS DETERMINED BY SOLUBILITY TESTS.

1. Methemoglobin prepared from coagulated hemoglobin by the reversal of coagulation has the same solubility within 2 per cent as normal methemoglobin. 2.

THE REACTIONS OF CYANIDE WITH GLOBIN HEMOCHROMOGEN.

Cyanide can react with globin hemochromogen in two different ways. In the first reaction cyanide combines with globin hemochromogen without displacing or competing with globin. In the second reaction cyanide displaces globin.

PROTEIN COAGULATION AND ITS REVERSAL : IMPROVED METHODS FOR THE REVERSAL OF THE COAGULATION OF HEMOGLOBIN.

The coagulation of hemoglobin is probably reversible. Several methods are described for preparing soluble crystalline hemoglobin from hemoglobin denatured by HCl or trichloracetic acid. The yield is about 75 per cent.

PROTEIN COAGULATION AND ITS REVERSAL : THE PREPARATION OF INSOLUBLE GLOBIN, SOLUBLE GLOBIN AND HEME.

1. By a procedure involving the use of acid acetone hemoglobin may be rapidly separated into a precipitate of denatured globin and an acetone solution of heme. 2.

PROTEIN COAGULATION AND ITS REVERSAL : THE REVERSAL OF THE COAGULATION OF HEMOGLOBIN.

1. The preparation from completely coagulated hemoglobin of crystalline soluble hemoglobin is described. 2.

THE PREPARATION OF COMPLETELY COAGULATED HEMOGLOBIN.

As a preliminary to the study of the reversal of the coagulation of hemoglobin several methods are described for the preparation of completely denatured and coagulated hemoglobin and the evidence is given that hemoglobin is a typical coagulable protein.

ON PYRIDINE HEMOCHROMOGEN.

1. Cyanide hemochromogen probably contains one cyanide group per heme group. 2.

PHYSIOLOGICAL ONTOGENY : A. CHICKEN EMBRYOS. XIV. THE HYDROGEN ION CONCENTRATION OF THE BLOOD OF CHICKEN EMBRYOS AS A FUNCTION OF TIME.

We have studied by means of glass electrodes the hydrogen ion concentration of the blood of chicken embryos from 8 to 20 days. When plotted as a curve, the average data show that a constant change takes place in the measurement, being acid at the beginning of this period and becoming alkaline toward its end. The acid reaction we think was characteristic not only of the embryos of fowl, but of the fetuses of cats and indeed as Warburg has shown of rapidly growing tissue in general.

HEME AND TISSUE IRON.

1. A method is described for estimating the heme in yeast and bees' muscles as pyridine hemochromogen. 2.

ON HEMOCHROMOGEN.

1. Every hemochromogen consists of the iron pyrrol complex, reduced heme, combined with some nitrogenous substance. 2.

ON SOME GENERAL PROPERTIES OF PROTEINS.

1. The processes of denaturation and coagulation of hemoglobin are like those of other proteins. 2.