This section is from the book "Practical Dietetics With Special Reference To Diet In Disease", by William Gilman Thompson. Also available from Amazon: Practical Dietetics with Special Reference to Diet in Disease.
The stools of the infant should be observed from time to time in order to ascertain whether the milk is being properly digested.
The stools of an infant fed exclusively on milk should number two (or only one) a day, and be of uniform soft consistence, smooth, of inoffensive odour, and of a gamboge-yellow colour. If meat juice or meat broth of any kind is given, the stools usually become darker. If too much is given they become acid, malodorous, very dark brown, and diarrhoeal.
Abnormal appearances of the stools will be found described in connection with the dietetic treatment of infantile diarrhoea (p-565). When farinaceous or any amylaceous food is being given, it is well to test the stools with a few drops of tincture of iodine which imparts a purple colour to any particles of undigested starch which they may contain.