324 Dr. R. D. Thomson 07i the Digestion of 



found to have imbibed a considerable amount of oily matter. 

 The white substance remaining on the filter presented charac- 

 ters similar to those of albuminous or fibrinous matter. 



The facts detailed having shown that there was a decided 

 distinction between the serum of a person previous to and after 

 taking food, it became an interesting point to pursue the in- 

 quiry, and to ascertain how long the milky aspect would con- 

 tinue in the blood. Accordingly, at six o'clock p.m., or six 

 hours after the meal, the individual was a third time bled to 

 the extent of seven ounces. The serum was in this case very 

 milky, and threw up, on standing, a considerable white scum 

 to the surface, which could be drawn up by a sucker and ex- 

 amined. On throwing the serum on a filter, a small portion 

 of white matter adhered to it, possessing albuminous charac- 

 ters; the serum passed through with a milky colour, but no 

 imbibition of oil coukl be detected on the filter itself. A 

 careful examination of this specimen of serum could detect not 

 a trace of starch by means of iodine and chlorine, and this led 

 to the investigations detailed in the subsequent parts of this 

 paper. 



The inferences deducible from this experiment appear to 

 be, — 1st, that the serum of a healthy individual at a certain 

 period of time, after partaking of a meal, is clear and limpid, 

 and corresponds with the description of this fluid as we find 

 it detailed in physiological works of authority ; 2nd, that in 

 three hours after a meal, when the food consists of vegetable 

 albuminous matter and oil or fat, the albumen begins to make 

 its appearance in the blood, while a still larger quantity of 

 fat in relation to the amount of the albumen taken into the 

 stomach exists in the blood ; and 3rd, that in six hours, while 

 the quantity of albuminous matter in the blood can be de- 

 tected, the fatty matter has comparatively disappeared ; a con- 

 clusion which is completely in accordance with the chemical 

 properties of these substances, since we know that some kinds 

 of fat liquefy nearly at the temperature of the human body, 

 and will, of consequence, be in a condition immediately after 

 their introduction into the stomach to enter the sanguineous 

 circulation along with the water present in the stomach, since 

 that fluid appears capable of permeating with great facility 

 the coats of the intestinal canal throughout its whole length. 



To determine the manner in which the food thus passes into 

 the circulating system, is scarcely the province of the chemist. 

 At the same time, since it appears to exist in the current of 

 the blood without having undergone much modification of 

 state from that which it originally possessed in the stomach, 

 there seem no obvious arguments to present themselves against 



