FATTY ELEME:XTS OF FOOD, AKD OH FATTEJIiXO. 419 



i» cob^nmed by a true process of combastion, which conrcrto iU 

 -jarbDQ into carbonic acid, and its hydrogen into water ; or otherwise, 

 •X 13 simply eliminated without change in the nrine. 



Fatty matters may, indeed, disappear under the first form ; bat 

 %o long as they escape remarkaUe modification, it is certain tint 

 ihey do not pass off by the urine, and that the quantity eliminated 

 by the perspiration is insignificant. Their ins^ubilitj, therefore. 

 retains them in the economy once they have eotered tftie blood or 

 the tissues ; and it is in virtue of this quality that tiiej cuaBlilole a 

 kind of mmgaxine of combustible matter in the umnl body. TUo 

 18 the principal reason wherefore individuala eapiilied with food mi 

 excess get fat, and that those insufficiently fed fiill leas ; the httj 

 matter being deposited in the interstices of the tiawca ia the foimr 

 case, being taken up from tbem and buned m the aeoood. 



This explanation is anractively simple ; bat ia oar attachment to 

 it we must not forget that other expiaaatiooe hare also been giren : 

 and in particular it must be contiaMed with a view which has been 

 formed upon certain inquiries undertaken by M. Dumas. It is 

 known, for instance, that sugar may be regarded as a eonpoaad of 

 carbonic acid, water, and olefiant gas. Now there is nnthiag to pie- 

 vent olefiant gas becoming d^aehed sad takia^ diiciea i t states of 

 condensation, to give rise to bodies whieh by onderg ois^ oiidstina 

 would produce fat acids and consequently fats. Since it has beea 

 known that the oil ofpot^ito spirit is also met with in the spint obtaia- 

 ed from the refuse of the grape, and ia the spint p to ca iod finaa 

 malt, and from the molasses of beeuroot sagar, the assorsace that 

 the oil is a product ef the fermenution of sogar ipposrs to be com- 

 plete. 



We ought even to be prepared to admit a pheoomen<»i of the same 

 kind as ta^ng place in plants, when we see the sugar of their stems 

 disappearing in the same ratio as their seeds or fiwts bee Mas charg- 

 ed with oleaginous matter : all the palms elabMate si^ar hefoia 

 producing oil. 



It is upon chemical views of this kind that the socoad opskai as 

 to the source of fat in animals has been formed, sod whieh may he 

 said to stand in direct contrast with that which assumes this sub- 

 stance as pre-existing in the food, which regards it as prodnced in 

 the blood itself, under the influences of the most intimate fagcoo of 

 animal life. For my own part, I adopt the view which lajiiiooes sa 

 animal to be supplied with fait alresidy formed, BMiafy ^miw it 

 presents itself to me as more in harmony with the foi^s which I 

 observe in oar stshles. Still I do not deny that it may be posiMhiii 

 for a certain qaaat^ of fat to be elaborated in the bodies of hsihi- 

 Torous animals, under the influence of a special fermeatatioa of the 

 sugar which forms an element in their food ; slthoogh I fod tntipfed, 

 from practical facts, that sugar plays no essentia] part in the fatten- 

 ing of cattle. 



The formation theory, nevertheless, is not without data of a very 

 curious and important kind, which require notice. Huber had ' 

 tluil bees fed upon honey, and even upon sugar, did not b^ 



