SUGAR. 277 



sugar is converted into lactic acid is probably dependent in part 

 on the observed fact that the acid reaction of the intestinal con- 

 tents is not very great, and in part on the belief that sugar which 

 is so readily soluble and is regarded as highly diffusible (not being 

 found in large quantities even in the small intestine) must be 

 resorbed with extraordinary rapidity. Since, as has been observed, 

 direct observations on the quantity of the lactic acid formed in the 

 intestinal canal are not practicable, we must look around us for 

 other positive facts, which may support either the one or the 

 other view ; such, for instance, as, if we could accurately determine 

 it, the proportion of sugar that passes in a definite time into the 

 blood or into the chyle, as its quantity in these fluids might be 

 compared with the quantity of the sugar-yielding carbo-hydrate 

 taken with the food. Although such calculations certainly might 

 be made from the investigations previously in our possession, yet 

 I preferred instituting certain experiments bearing directly on this 

 question.* 



The experiments were made on horses, whose food consisted 

 of a mixture of equal parts of boiled and raw potato-starch ; this 

 was mixed with about one-twelfth of rye-bran, and formed into 

 balls, of which from 2,000 to 3,000 grammes were daily given to 

 the horses at intervals of two hours. The quantity of starch in 

 the dried balls was determined by the method of Liebig and 

 Horsford. They had, additionally, about 1 kilogramme [nearly 

 2*2 Ibs.] of sugar in the 24 hours. This feeding was continued 

 for three days, and on the last day the amount of starch in the 

 excrements discharged in 24 hours was ascertained by digestion 

 with dilute sulphuric acid, and the subsequent determination of 

 the carbonic acid developed by fermentation. The animals were 

 killed about an hour or an hour and a half after the last feeding, 

 when the intestinal contents were examined, and the chyle as well 

 as the portal blood was submitted to a careful analysis in reference 

 to the quantity of sugar contained in those fluids. 



The horse A took in the last 24 hours 1584 grammes of dry 

 starch in balls ; as 234 grammes were found in the excrements, 

 the animal had consumed 1350 grammes in 24 hours; conse- 

 quently 1500 grammes of sugar must have been resorbed [nine 

 parts of starch being converted into ten of glucose or grape- 

 sugar] . 



The horse B consumed 1235*3 grammes of starch on the third 

 day of the experiment ; as 321'5 grammes of starch were found in 

 * Ber. der k. sachs. Gesellsch. der "Wiss. Jahrg. 1850. S. 130. 



