Of the three forms of condensed milk, (1) unsweetened whole milk condensed, (2) sweetened whole milk condensed, and (3) sweetened skimmed milk condensed, the first is the only one that should be used. When water is added to it in proper proportions, it will resemble whole cow's milk. To make it resemble human milk, cream and milk-sugar must be added to it just as to ordinary milk. If either of the other kinds of condensed milk is used, it must be so greatly diluted to reduce its sugar percentage to a proper one, that it will contain a very small percentage of fat. For instance, if one of the second group of condensed milks is diluted as the directions with it advise for infants' use, it will average less than 1 per cent, of fat. If the third group is used, the percentage of fat given to the baby will be still less.
The presence of cane-sugar in the last two groups of condensed milk makes them liable to ferment and to excite gastrointestinal trouble. On the other hand, its absence in the first lessens the keeping power of the milk after the can is opened.
Condensed milk is not necessarily sterile, although by condensation it is made to keep well for long periods. It is condensed at too low a temperature to sterilize it. Pathogenic micro-organisms are not always destroyed during its manufacture, but may lie dormant in it or grow with slowness.
Babies fed upon condensed milk often look plump because of the abundance of sugar in their diet, but they are likely to be pale, flabby, and to lack power to resist disease. Frequently a malady resembling scurvy develops in those fed exclusively upon such milk. This can be partly counteracted by feeding orange- and grape-juice to such babies.
In the process of condensation some change is wrought in the milk that makes it more digestible than fresh cow's milk. This probably accounts for its agreeing with many delicate children when fresh cow's milk will not. According to my experience, percentage milk can always be made to agree with such infants as well as condensed milk, and usually better. It is not advisable to use the latter except when fresh cow's milk or human milk cannot be had.