Nannette Metzger

Behavior of the Thyroid toward Elements of the Seventh Periodic Group. I. Halogens and Thiocyanates.

Summary 1. Thyroid filters preferentially and accumulates thiocyanates as well as all the elements of the seventh periodic group that have been studied, viz., Cl, Br, I, Mn, At. 2. All halides and thiocyanates when administered in relatively large amounts compared with iodine wash inorganic iodide from the body and prevent new supplies of iodine from being received by the thyroid, thus producing thyroid hyperplasia and goiter. It is suggested that these ions exert, at least in part, a mass action-like effect. 3. It is further suggested that similarity in arrangement of electrons in the outer shell of the elements of the seventh periodic group enables the thyroid to differentiate between them and other elements.

The chemical composition of the vitreous humor of animal eyes.

A survey of the literature revealed but incomplete data on the chemical composition of the vitreous humor. It was therefore deemed advisable to determine in this body fluid the concentration of some of the compounds known to occur in the blood and cerebrospinal fluid. This work represents a preliminary step in the study of the humors of normal and pathological human eyes. The use of the microchemical methods has made possible the more extensive analysis of the vitreous humors of individual eyes. Analyses were made of the vitreous humors of the eyes of oxen, horses and pigs. The eyes were removed, without trauma, from the animals immediately after slaughter. The aqueous humor was withdrawn by a syringe, and the entire vitreous shelled out through an incision in the sclera of the posterior part of the eyeball. After rupturing the membrane, the vitreous was poured upon a C. S. and S. filter paper No. 595, and covered with a watch glass. The filtrate was taken for analysis. All material analysed was fresh. Not more than 45 minutes elapsed between the death of the animal and the beginning of the analysis. The oxen and pigs were young animals, but the horses ranged from 12 to 20 years. The horses were killed instantaneously by a shot into the brain. All animals were free from disease. The analytical studies included determinations of total solids, specific gravity, proteins, non-protein nitrogenous compounds, chlorides, sugar, phosphorus, sulphur, potassium, sodium, calcium, lactic acid and the ether soluble fraction. All results are reported in terms of mg. of these components to 100 cc. of the filtrable portion of the vitreous. The figures reported in the table are averages of from 6 to 12 determinations.

Ascorbic Acid from Iris and Other Plants by a Simplified Method.

We have had great difficulty in obtaining more than a few milligrams of the antiscorbutic vitamin, ascorbic acid, from either plant sources or suprarenal glands by the published methods of Szent-Györgyi 1 or of Waugh and King 2 and Svirbely and King. 3 Large and uncontrolled losses occur at many places in both processes as published. Svirbely and Szent-Györgyi 4 have just reported a somewhat modified procedure, using the Hungarian sweet pepper from which paprika is made, which contains considerably more vitamin C than we have obtained from the American sweet pepper—another variety of Capsicum annuum. We have studied the causes of these losses with a view to developing a more certain method of preparation. A survey of common plants was also made to find richer sources of the vitamin. Some of these results have been published by Marine, Baumann and Webster. 5 Leaves of German iris (Iris germanica) are by far the most satisfactory material from which to extract vitamin C, both because the vitamin is present in high concentration and because there are fewer substances in this plant that interfere with its separation. Most plants have a relatively high concentration of ascorbic acid in the young actively growing portions but on maturation, the vitamin rapidly disappears. In German iris leaves, however, the concentration of the vitamin, which is 600 mg. per 100 gm. of fresh leaf in early spring, remains as high as 250 or 300 mg. per 100 gm. in late summer, and this plant offers a very rich source during the entire growing season. Skunk cabbage (Symplocarpus foetidus) gathered during April and May and sweet green peppers as purchased from January to May both contained between 100 and 200 mg. per 100 gm.