The existence of different bonds between unsaturated fatty acids and oxygen led us to study different bonds similarly occurring between the same fatty acids and sulfur, the second member of the oxygen series. The treatment of polyunsaturated fatty acids or their triglycerides with sulfur has shown that two different formations can be obtained. By heating the mixtures above 110° but below 125° C, precipitated sulfur is incorporated without a manifest change in color or other properties. The iodine number is not changed. When conjugated fatty acids or their triglycerides are treated, no changes are seen in the spectral analysis. By heating above 130° C, the color of the preparation changed progressively reaching deep red brown if the treatment is sufficiently prolonged. Concomitantly, the iodine number decreases progressively and eventually reaches zero. The spectral analysis of the conjugated fatty acids shows the peaks going progressively down until no more conjugated formations are present, indicating that these changes affect the double bond.

The analogy between the fixation effects of oxygen and sulfur has suggested that the first bond corresponds to a hydropersulfide similar to a hydroperoxide. The second bond would represent a fixation of the sulfur at the level of the double bond itself, similar to a peroxide. Studies of similar bonds of sulfur were made in tetralin where hydropersulfides were obtained. The study of the properties of all these preparations seems to confirm the hypothesis that the compounds obtained are hydropersulfides.

Quenching of methylcholanthrene fluorescence in samples obtained when 0.5% sulfur in cottonseed oil was heated

Fig. 291. Quenching of methylcholanthrene fluorescence in samples obtained when 0.5% sulfur in cottonseed oil was heated from 120°C to 280"C. The samples were dissolved in ether alcohol mixture and mixed in equal part with .0125% methylcholanthrene. The existence of concomitant changes in the oil with sulfur and in the oil alone, indicates that the variations correspond primarily to changes which take place in the oil itself when heated.

We studied the changes in the quenching effect upon the fluorescence of methylcholanthrene which occur when sulfur added to a mixture of triglycerides is heated. This was compared with the effect of heating upon cottonseed oil alone. Fig. 291 shows the results of this analysis.

Chapter 12, Note 9. Magnesium And Adrenalectomy

The biological antagonism between homotropic magnesium and het erotropic sodium, both acting at the metazoic level, has led us to the study of the specific influence exerted by magnesium upon the recovery processes in adrenalectomized rats. It is known that, while an adrenalectomy is not always fatal in old rats—death occurs uniformly in younger animals weighing less than 150 grams. The administration of 1% sodium chloride as drinking water is known to protect the adrenalectomized animal and, if administered for a sufficient length of time, to prevent death. The administration of magnesium sulfate by repeated injections of .5 cc. of a 10% solution per 100 grams of body weight or even orally as .5—1 % in drinking water has an antagonistic effect to that of sodium chloride. A 75% mortality rate in older animals receiving magnesium sulfate as compared to a 20% rate in the untreated was seen. Similarly, in young animals receiving magnesium sulfate in addition to salty drinking water, the mortality rate in some experiments was over 80%.