PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 829 



to satisfy their cravinir. It is said many children on the verge of 

 death have been saved by the use of this new preparation. Iiwa- 

 lids, and especially mothers during the period of nursing, have 

 been greatly benefited by this food. As careless or ignorant ser- 

 vants may not always correctly mix the ingredients mentioned, the 

 article is now carefully manufactured under the name of " lactine; " 

 but ahnost any American housekeeper can prepare the mixture 

 from the directions above given. 



Liebig asserts that one-half the deaths of infants, deprived of 

 their natural food, may be ascribed directly to the use of the cus- 

 tomary pap. There are doubtless other mistakes made in the 

 management of children, for of all the deaths in the United States, 

 according to the last census, not less than twenty per cent, were of 

 children under twelve months old. 



The Smoke Question. 

 Dr. E. Angus Smith, F. R. S., states that the amount of uncon- 

 sumed carbonaceous matter which passes oiT from the chimneys in 

 the city of Manchester, England, is sixty tons a day. A very 

 small amount affects the atmosphere ; a grain in eighteen cubic 

 feet is sufficient to convert good air into Manchester air, as far as 

 the carbon is concerned. About one-half is due to tarry matter, 

 and the other half to carbon only. The black matter is the color- 

 ing material of all the smoky towns of England, and to a great 

 extent of the clothes, as well as of the person of the inhabitants. 

 They live in houses colored by it, and walk on roads colored by 

 it, and can see the sun, the moon and the heavens only after hav- 

 ing been, to their eyes, colored by this universal tincture. All the 

 coal used in England is soft or bituminous, containing always one 

 per cent, of sulphur, and sometimes much more. This unites with 

 the oxygon of the air, and forms sulphurous acid. It is the sul- 

 phur acids which render the air and rain of Manchester so destruc- 

 tive to metals. Iron roofs will not remain there ; even houses 

 cease rapidly to exist, and become old at an early period. The 

 lime of the mortar becomes sulphate of lime, and the rain washes 

 it away. The very stones decay under the action of acid, and the 

 bricks crumble more rapidl3\ Even in places less troubled with 

 smoke the decay is seen. The Parliament houses of London, built 

 to remain for ages, are decaying rapidly, and turning into gypsum 

 and epsom salts. The finest buildings in London appear less hand- 

 some than flimsy structures in many continental cities. The pccu- 



