are: variations of heat and cold, and constant inhalation of dust; these causes produce chronic bronchitis and asthma. The paralytic diseases are induced by lead; of these diseases the victims are the dippers and the women who assist them. "Could we," remarks Dr. Richardson, in conclusion, "relieve the earthenware manufacturers from the two grand causes of disease to which they are exposed, dust and lead, though some generations would be required in order to restore them, as a community, to perfect vitality, there is no reason why their death-rate should not, at once, be reduced to at least half its present excess, and the steady progress of their vital regeneration be immediately commenced."
Effects of Cold on Milk.—The effect of cold upon milk has been made a subject of experiment by M. Eugène Tisserand, who finds that if cow's milk is immediately, or soon after being drawn, placed in vessels at various temperatures between freezing-point and 90° Fahr., and the initial temperature maintained for twenty-four or thirty-six hours, the nearer the temperature of the milk is to freezing-point the more rapid is the collection of cream, the more considerable is the quantity of cream, the amount of butter is greater, and the skimmed milk, the butter, and the cheese, are of better quality. These facts, he believes, may be explained by Pasteur's observations on ferments. It is probable that the refrigeration arrests the development of living organisms and hinders the changes due to their growth. The facts stated indicate room for great improvement in the methods of storage and preservation of milk. To keep milk at its original quality, extreme cleanliness and a low temperature are absolutely necessary. In the north of Europe the value of cold is already recognized, and in warmer climates the need of its assistance is greater.
Coal-Gas as a Fuel.—The use of coal-gas in the place of gross fuel for the purposes of heating and cooking is rapidly coming into public favor in England. In this country the high price of gas is doubtless the principal reason why this most convenient form of fuel has not been more widely adopted, in the place of coal. The advantages of gas are manifold, and are clearly set forth in a paper read by Mr. John Wallace at a meeting of the London Society for the Promotion of Scientific Industry. First, we can absolutely control the amount of gas consumed and the degree of heat produced. In cooking, this control of the degree of heat is of the utmost importance: too quick or too slow a fire must result in bad cooking. Now, the heat of a coal-fire is very irregular, and is liable to be affected by so many circumstances that constant attention is required to keep it in the proper condition for delicate operations. Then, in point of cleanliness and facility of application, gas-stoves are far superior to coal-stoves. "The increasing cost of household labor," adds Mr. Wallace, "renders it highly probable that the same measure of success awaits the domestic application of gas as has already established the sewing-machine among our household gods. It is to be hoped that among the numberless schemes of gas-manufacture which have recently been made public we may soon be provided with a gas which shall be sufficiently cheap and plentiful to be used not only for lighting and heating in private dwellings, but also for trade and manufacturing purposes in workshop and warehouse."
Toxic Action of Putrid Blood.—The influence of various conditions upon the toxic property of blood has been investigated by V. Feltz, whose results, as communicated to the Paris Academy of Sciences, are briefly stated in the Lancet. He first determined the effects on a healthy dog. The injection of from one to three cubic centimetres caused all the symptoms of intense blood-poisoning in from three to eight days. Exposure to the air for periods of 24 to 96 hours made no difference in the toxic properties of the blood; exposure to compressed air for 24 to 144 hours was also without effect. Exposure to oxygen had different results, according to the time of exposure. Contact with oxygen for from 6 to 72 hours had no effect. Animals injected with blood which had been exposed to oxygen for 96 to 216 hours recovered after five or six days' illness. The result was the same with blood through which a continuous stream of oxygen was passed. A very similar effect was
