Scientific.

Waikato Times, Volume XXVI, Issue 2140, 27 March 1886, Page 2 (Supplement)

Scientific.

—To Mark TkanssH ckvt I'ai'KU. — T iko a «nv' itivo on the paper artd pin it, pipi r side up, on a board. Apply butter (cold) .ill dm i it, with the finger&j put on plenty Tlwri hrtld tnc ne^ativc'over ft j)Uilhn '•tove, with the fl mi" turned iuw. Thu butter will at ouco begin to melt. Whili' it h melting, hold it in the li'ff hiuul, and with the fingers of tlie litrht hand keep the melting butter Jxuwinj? over tho - less greased portions,, and with the left hand move the negative nhfiut. Cuutiimo till an even surface U obtained, which will bo in about five ' inimltcs or less, dopoiiding on tho Bi/o of tfie negative. Then lay. paper side -«tlll tip, on u board or doth, and, while warm, rub, 'off tho surplus butter with tufts of cotton wool; it will be necessary torewarm the negative several time* during thin operation. Should any butter, by chimcf, get on the firm fide of the nVgativo, warm it and rub it with cotton wool, and it will at once come off. Give a final rub with cotton wool dipped in nlcohol, and tho negative i» icady to print from, and has a fine ground-gUss aftnearancG.

—A Njsw Light.— From Vienna we learn that experiments are being made at A'rofesaor Licbeo'e chemical laboratory, with a now gnaYight inrented by Dr Aver. A cotton wick, saturated with an incombustible metal solution, is introduced into the flame of an ordinary Bunsen lamp, tio result being a liprht similar to the incandescent electric light.

— Nukskry Tlmpekatdrk. — According to General Morin, the eminent expert, the prpper temperature in well-ventilated places is as follows : Nurseries, asylums and schools, G9 degrees ; workshops, barracks and prisons, 59 ; hospitals, 61 to 6i ; theatres and lecture room", 60 to 69. In dwellings in this country it has been the ciißtom to keep the temperature at 62 to 70 degrees.

,-t-Sawdd^t Bricks. — A Chicago firm is engaged, in making bricks out of a .mixture of sawdust and clay. They, are subjected to a hoavy pressure, burned like a common brick, and ia some way made waterproof. They measure 13 by fi by 4 inches, and have two square holes running through, them lengthwise, they weigh littlo more than common brick, although four times as large. They are laid between the outer and^inner courses of a wall.

— (Josqerning Milk. — M. Toussaint has given the result of his re&eaiches ou milk from cows fed on brewers' grains. Some years ago, M. G^ra,rd drew attention to the fact tliat milk from cows fed on, gramas ;s , injurious. Later on M. Pelle, and algo a number of veterinary surgqqns, opposed M. Girard's belief. MM, Pelle and Breard argued according to aualysis, the milk was good, and therefore it was .wholesome ; but M. Toussaint maintains milk* may be chemically, good, and yet not digestible. The author examined the death -register 0/ 'Argenteuil, and he ascertained thaf deatlis, from gapti;o-enterij,is, and from lotcstiual affections, were more frequent among bottLe : ,fed children since a large distillery' had been established, there. Milk from cowaio which the malt- refuse Irom the distillery is, given is acid, and is not digested by ( children.,

• — Un.evtip.iltty of Cheese. — The digestibility of cheese depends a good deal, according to Klenze, on its physical properties. All fat cheeses are dissolved or digested with great rapidity, because the molecules of casein are separaie.d only by the fat, and so the solvent juice can attack a large surface of the cheese at one time. Whether the tihefse be hard pr soft does not appear to matter, and there is no ' connection between the digestibility and the percentage of* water , present in the cheese. The degree of ripeness and the amount of fat have, however, considerable influence, for both these conditions render the cheese more friable, and so allow of intimate contact of the juice. Cheddar took the shortest time to digest (four hours), whilst' unripe Swiss cheese required ten hours for solution.