Of what sort must the chosen diet be which can favor the ripening of the ovum? Always only such a diet as can so modify the process of food assimilation in the organism that no excretion even of the most minute quantity of sugar discoverable by the application of the phenylhydrazin test can be detected.
The quantity of sugar is small, but what has to be taken into consideration here is not so much the amount of the sugar, as the fact that this substance is being excreted.
Now, it has been proved by experience that when in an organism a symptom appears, as the evidence of disease, in the form of a considerable excretion of sugar in the urine, it is in many cases possible, by the means of fitting diet, to produce a diminution of the excretion of sugar, either bringing it down to a small amount or causing it to disappear altogether.
Investigation of the urine according to recognized methods must accompany this system of diet, and, under normal circumstances, we soon meet with the phenomenon, at which we have been aiming—that the quantity of sugar has diminished to a no longer perceptible amount. When this has been attained, it may be presumed that, by a further perseverance with the same diet, the metabolism will be so regulated that, if no pathological accident supervenes, the excretion of sugar will cease. In fact, in consequence of an alteration of diet and the taking of no excessive quantities of starch and sugar, the excretion of sugar in the urine ceases for a considerable time, and only makes its reappearance after a long interval.
When, in consequence of having observed the minute normal quantity of sugar in the urine, my attention was attracted to the fact that the determination of the future sex was connected with the presence of this sugar, my endeavors were directed to exercising such an influence over its presence as might enable me to get rid of it. Experiments with the most diverse diets gave me in the case of women most remarkable results. In this way I found women, using an almost exclusively flesh diet (which was, of course, especially rich in nitrogen), whose urine showed greater quantities of sugar—according to approximate estimations—than when they used a diet of carbo-hydrates, that is, sugar, fatty substances, alcohols, etc. Others, again, showed an exactly opposite result. In many cases I did not succeed in getting rid of the normal sugar in the urine; in others it disappeared soon after the beginning of the treatment. It follows that, in every case where the question is one of so influencing the sex that a male offspring may be obtained, the very first thing to be determined is whether the normal quantity of sugar is present in the woman’s urine or not. If none can be detected after repeated and painstaking search, and if reducing substances are plentifully present, we do not require to arrange the diet, but can recommend immediate impregnation, as every probability points to a male embryo. But in all cases where the normal “urine-sugar”—if I may so call it—is present, even if only traces of it are to be found, it will then be our task, by various alterations of diet, to discover that one which seems suited to the organism in such a way that it will occasion the disappearance of every trace of the “urine-sugar.” In these experiments the remarkable phenomenon is observable, that the reducing substances which I have already mentioned, and amongst these especially the lævo-rotatory glycuronic acid compounds, show alterations in respect of quantity.
In fact, I found that the urine of most women who had male offspring contained, during the first months of pregnancy, more reducing substances than the urine of women who had female offspring. It is, therefore, also necessary that the diet should not only occasion a disappearance of the normal urine-sugar, but should also produce an increase of the reducing substances. This end can be accomplished certainly also by the use of different medicines, such as chloroform, turpentine, salicylic acid, etc. But, apart from the fact that medicinal influences are distinctly to be discouraged, these substances do not seem to produce the same effects as diet. Besides, it is still a question of what kind these efficient substances are. And another question is whether they are themselves effective. It will be sufficient for us to recognize them as a symptom.
It is known that the male sex possesses a distinctly greater amount of albumen than the female. In age this difference disappears; in youth it is greater. It might be expected that male offspring would result, in consequence of a more albuminous diet, by which a greater increment of albumen would be made possible; the thing, however, is not quite so simple as this. Investigations in various cases showed me that women in whom an increased amount of albumen could be detected, but in whom either sugar was present to a small extent, or, on the other hand, only very small quantities of reducing substances could be detected, almost always had female offspring.