Vegetable Albumen, Fat and Starch. ' 325 



the conclusion that the food is directly absorbed from the ali- 

 mentary canal by the blood-vessels themselves. 



In confirmation of the experiment already detailed, the 

 physiological part of which was conducted by Dr. Buchanan, 

 whose great merits as a physiologist and original observer re- 

 quire no encomiums from me, various repetitions on the in- 

 ferior animals were conducted by myself, which it would serve 

 no purpose to enumerate minutely, since they all conducted to 

 the same results. 



In the majority of these cases calves were fed on gruel and 

 milk, and after various intervals they were slaughtered. The 

 serum on examination, when the animal was killed from three 

 to six hours after the meal, was found to be milky, and to 

 leave a greasy stain on filtering paper when the amount of 

 milk or fatty matter used was considerable, while the serum 

 taken from an animal which had been subjected to starvation 

 for a space of time varying from twelve to twenty-four hours, 

 presented generally a clear aspect. It has been frequently re- 

 marked that the serum of diabetic patients exhibits often a milky 

 appearance, and the circumstance of the coexistence of disease 

 with the white serum was considered as a proof that the disease 

 was the cause of the colour of the liquid part of the blood; but 

 it has been very properly remarked by Dr. Buchanan, that the 

 large amount of food consumed by individuals affected with 

 this disease, affords a satisfactory mode of accounting for the 

 presence of such profuse quantities of albuminous and fatty 

 matter in the blood in such instances. I have recently had 

 opportunities of studying this form of serum through the kind- 

 ness of Dr. William Thomson, and I have found no reason 

 to conclude that the blood of diabetic patients, so far as its 

 milkiness is concerned, is more diseased than that of healthy 

 individuals after a full meal. It is no doubt highly probable 

 that the blood in these instances remains for a longer time 

 loaded with the white matter than in the healthy state of the 

 organism, and that the appetite may, by continually urging in 

 a new suppl}' of food, thus produce a diminished rate of di- 

 gestion or assimilation in the circulating system; but the pre- 

 sence of the white matter in the serum it would be erroneous 

 to consider as a symptom of disease, at least in so far as the 

 data entitle us to draw such an inference. 



Changes jyroduced on Starch in Digestion. — As it appeared to 

 be a matter of importance in the investigation of the changes 

 occurring in the stomach during digestion, in order to prevent 

 complication of the phaenomena, that the food should be as 

 simple as possible, I have chosen for the experiments about 

 to be detailed, cases in which animals were fed on vegetable 



