PAT METABOLISM 



thus produced is compared in an optical apparatus, called a nephclometer, with a 

 standard Bolution of tun milligrams of < 'l<-i<- acid treated in 1 1 1 < ■ Bame way. I ; • tatty 

 acids in human blood arc mainly oleic and palmitic. 



Thr lecithin ami cholesterol max also I" estimated in the Bame blood extract. 

 lecithin tin' above exl racl of blood, after the removal of tin' alcohol ami ether, is <li;_" 

 1 iy heating with concentrated BNO and H 80 4 . Thia decomposes the lecithin, liben • 

 the phosphorus, a solution of the res ilting ash being rendered faintly alkaline to phenol- 

 phthalein and then bIowI) added to a Bilver nitrate Bolution. The density <.t" tin- 

 cipitate thus produced is compared in the nephelometer with thai of a precipitate pro- 

 ■ In 1 iu the Bame an it of Bilver nitrate by adding to i1 a Btandard phosphoric 



BOlul i n. 



For cholesterol an aliquol portion of the above extract i- saponified with sodium 



ethylate and then Baturated with chloroform; the chl form extract is mixed with a 



anhydrid and II. so, (con.) until the bluish color is fully developed (Liebermann i 

 tion), the intensity of which is then compared in a colorimeter with that obtained by 

 similar treatment from a Btandard cholesterol Bolution. 



Variations in Blood Fat. In the dog the percentage of fat in the 

 blood is remarkably constanl under normal conditions. After a fatty 

 meal the increase in fal begins in aboul an hour, and reaches its maxi- 

 mum in aboul six. The increase is qo1 found in animals in which the 

 thoracic duel lias been ligated. Although this result would Beem to 

 contradid the view held bj some thai part of the fat which can not 1"' 

 accounted for in t lie thoracic-dud lymph is absorbed by way of the 

 portal vein, it does no1 by itself disprove the hypothesis, for it has been 

 found that the fat contenl of tin- portal blood is always higher titan that 

 nf the jugular. 



Very interesting results have been obtained following the intravenc 

 injection of emulsions of nil. either the so-called casein emulsion or col- 

 loidal suspensions. Up t<> a dose of 0.4 gram per kilogram of h<i<ly 

 weighl which by calculation would Buffice t<» raise the fal contenl of 

 the hi 1 by LOO per cent — there was no increase in fat content. In or- 

 der to explain this disappearance of fat, it mighl be imagined that thr 

 injected fal particles formed emboli in the smaller capillaries. Againsl 

 such a view", however, is thr tact that the particles of fat in these emul- 

 siuiis an' one-half to one-seventh the size of a red corpuscle. Although 

 this argumenl is no doubl of some weight, it should he remembt 

 that the physical condition of this,- fine fat globules is not the samt 

 that of the m\ blood corpuscle. Their Burface condition maj he such 



that they readily agglutinate BO as in form small massrs, which may 



stick at the branching of the smaller arterioh capillaries. Bit 



himself suggests thai the injected fal maj be stored, possibly in the li 



since the fat in this organ, as we shall see later, inert similar 



conditions. When twice thr above quantity was fed in the form • 



