738 



SCIENCE. 



[N. S. Vol. VII. No. 17S. 



cesses, whereby a certain quantity of heat 

 is lost to the body. This physiological out- 

 put of carbohydrate is in the male sex most 

 marked during the period of growth — that 

 is, between the ages of 14 and 19. In 

 women there is no corresponding increase, 

 but small quantities may appear in the 

 urine before and after menstruation, while 

 Iwanoff and others have shown that gly- 

 cosuria is common in pregnant and par- 

 turient women. Now the amount of sugar 

 normally excreted is equal in men and 

 women, but more significant in the latter 

 owing to the lesser activity of their meta- 

 bolic processes. For the perfect ripening 

 of the ovum it is necessary that oxidation 

 shall be perfect — that is, that no sugar shall 

 be left unburnt. Where there is a remain- 

 der of unburnt sugar the ovum stands a 

 chance of being less ripe, and less well 

 nourished. Hence the properties of its 

 protoplasm are less well developed, and by 

 the theory of crossed inheritance it is more 

 likely to produce a female chUd. On the 

 other hand, when the urine is free from 

 sugar the ovum can attain perfect develop- 

 ment, and give rise to male offspring. It 

 is upon this cardinal principle that Pro- 

 fessor Schenck's theory is based. He holds 

 that a prolonged course of appropriate 

 nourishment both before and after fertili- 

 zation will tend to the conception of male 

 children only. 



The next question is of the means to be 

 adopted to ensure this end. If a male child 

 is desired, and the maternal urine contains 

 no sugar, but abundance of reducing sub- 

 stances (particularly the Isevo-rotatory 

 glycuronic acid), he allows impregnation 

 forthwith. If, on the other hand, sugar is 

 present it must be removed, and the reduc- 

 ing substances increased before fecundation 

 may take place. It is found that the urine 

 of a woman pregnant with a boy contains 

 more reducing substances than that of one 

 with a girl. "We need not enter into the de- 



tails of the diet recommended, beyond say- 

 ing that it contains much proteid, which 

 seems to be required by a male embryo. 



Finally Professor Schenck gives what 

 may be called his clinical results. He 

 quotes numerous cases to show that the 

 bearing of female children is associated 

 with glycosuria. In such instances he 

 recommends a diet comprising plenty of 

 proteid and fat, and as little carbohydrate 

 as can be tolerated ; this must be taken for 

 two or three months before and three months 

 after impregnation. He gives one example 

 in which six boys were born in succession 

 under this treatment, and a girl immedi- 

 ately it was relaxed ; and others in which 

 boys were born after repeated births of girls 

 before the treatment. In all, out of seven 

 recorded cases, six were successful. He 

 concludes that the nutrition of the mother 

 plays a most important part in the deter- 

 mination of sex, and that in countries 

 where much flesh is consumed there is a 

 marked preponderance of male children. 

 This can be imitated artificially, but it is 

 far more important to ensure the complete- 

 ness of oxidation processes in the body. 

 As long as the combustion of the food is 

 perfect, and the urine is totally free from 

 sugar, the exact amount of meat consumed 

 is of secondary importance. The birth of 

 male children can thus, in certain cases, be 

 predetermined, but the voluntary produc- 

 tion of girls is a problem as yet unsolved. 



CONVERSAZIONE OF THE ROYAL SOCIETY. 



The first of the annual conversaziones of the 

 Eoyal Society was held on May 11th, in the 

 Society's rooms at Burlington-house, the 

 guests being received by the President, 

 Lord Lister. 



The London Times states that there was 

 the usual exhibition of objects, apparatus, 

 processes, and experiments illustrative of 

 some of the most recent advances in scien- 



