Milk and Eggs are permissible in a vegetarian dietary, and as a rule, vegetarians use them.  Eggs, with the exception of such as are unfertile, are of course alive; but they have no conscious existence, and cannot be said to suffer any pain on being killed and eaten.  An objection to their use as food is, that on an egg and poultry farm, the superfluous male birds are killed, and as the hens become unprofitable layers they are also killed.  A similar humane objection applies to the use of cow’s milk by man.  The calves are deprived of part of their natural food, the deficiency being perhaps made up by unnatural farinaceous milk substitutes.  Many of the calves, especially the bull calves, are killed, thus leaving all the milk for human use.  When cows cease to yield sufficient milk they too are slaughtered.  Milch cows are commonly kept in unhealthy houses, deprived of exercise and pure air, crowded together, with filthy evil smelling floors reeking with their excrements, tended by uncleanly people.  With no exercise and a rich stimulating diet they produce more milk; but it is no matter for surprise that tuberculosis is common amongst them.  When the lesions of tubercle (consumption) are localised and not excessive, the rest of the carcase is passed by veterinary surgeons as fit for food; were it otherwise, enormous quantities of meat would be destroyed.  As butcher’s meat is seldom officially inspected, but a very small part is judged by the butchers as too bad for food.  In mitigation it may be said that poultry lead a happy existence and their death is, or should be, quickly produced with but little pain, probably less pain than if left to die from natural causes.  The same cannot be said of cattle and sheep when the time arrives for their transport to the slaughter man’s.  It is argued by vegetarians who take milk and animal products that they are not responsible for the death of the animals, as they do not eat their flesh.  As vegetarians profit by conditions in which the slaughtering of the animals is a part, they cannot be altogether exonerated.  Cow’s milk is prone to absorb bad odours, and it forms a most suitable breeding or nutrient medium for most species of bacteria which may accidentally get therein.  By means of milk many epidemics have been spread, of scarlet fever, diphtheria, cholera, and typhoid.  Occasionally milk contains tubercle bacilli from the cows themselves.  By boiling, all bacteria, except a few which may be left out of consideration, are destroyed.  Such a temperature, however, renders the milk less digestible and wholesome for infants.  By heating to 160 deg.  F. or 170 deg.  F. for a few minutes, such pathogenic germs as are at all likely to be in milk (tubercle, typhoid, diphtheria, &c.) are killed, and the value of the milk is but little affected:  this is called Pasteurising.  It was until quite recently a common practice to add boric acid, formaldehyde and other preservatives; this has injured the vitality and caused the death of many infants.  They have not yet gone quite out of use.