BIOGRAPHICAL SKETCH OF HENRY MILNE-EDWARDS. 719 



the origin of the fat of animals, a dispute connected with a question of 

 more extended bearing — that of the origin itself of the direct principles 

 of human beings. Some thought that vegetables alone make fatty 

 matter; that introduced by food into the bodies of herbivorous animals, 

 it tben passes into the tissues of those animals which are powerless of 

 themselves to form it. Such was the opinion entertained in the dis- 

 cussion by the greater part of intelligent minds, especially by Boussin- 

 gault, justly considered an authority on these questions. Others, Liebig 

 in i)articular, thought on the contrary that the fundamental chemical 

 agencies which govern production of the direct principles have the 

 same source in vegetables and animals, and they advanced in support 

 of this theory several proofs carefully deduced from the production of 

 fatty substances. But these proofs were indirect and were deemed 

 insufficient by their opponents. A long controversy ensued; it was cut 

 short, but not by the study of the agencies which engender fatty sub- 

 stances — agencies still unknown. The definite result of the process 

 however may be known by determining the relative weight of fatty 

 substances contained in the organism and in the food of mammals and 

 birds in various periods of their existence, i)articularly in the condi- 

 tions of fattening domestic animals. 



Milne-Edwards, associated with Dumas, made an ingenious and deli- 

 cate demonstration as a result of his study of insects. This related to 

 the i)roduction of tlie honey which bees manufacture so abundantly. 

 Determining by comj^arison the quantity of fatty matter that pre-exists 

 in the bodies of bees — a quantity relatively minute — and by feeding a 

 hive exclusively with the sugar necessary to the fabrication of their 

 honeycombs, the authors established as a fact that wax is made at the 

 expense of the saccharine element; that is to say, without the aid of a 

 fatty substance furnished by alimentation. The test was exact; added 

 to others made in various places, it carried conviction to all, even t(j its 

 opponents. 



There is another book of Milne-Edwards that should be taken up as 

 a proof of the superior tendency of his mi)ul; this work belongs to the 

 early period of his career when he was dividing his energies between 

 his medical vocation and his scientific studies. This was a publication 

 made in 1829, in company with the philanthropic political economist, 

 Villerme, and related to the influence of temperature upon the mortal- 

 ity of newly-born infants. The authors showed how these infants are 

 exposed to danger under the influence of variations of temi)erature, 

 especially of cold, their organs being as yet unaccustomed to react 

 against the surrounding medium. Kow the rules relating to obligatory 

 l^^esentation of newly-born infants before the officer of the civil govern- 

 ment, as well as to their baptism in church, exj^ose them to a chill dan- 

 gerous in proportion to the low degree of the outside temperature. The 

 authors proved this to be cause of mortality, by statistics compiled at 

 different seasons and in distinct localities, and demanded a reform of 



