SCIENCE-SUPPLEMENT 



draught. Peat burns freely when dry, and makes 

 a hot fire. It is lower in heat value per pound 

 than coal but it gives out proportionately more 

 heat, due to its relatively higher oxygen content. 



There is no soot from a peat fire, but if not 

 handled properly a light smoke eari*7ing the odor 

 of burning leaves may get into the room. Peat 

 makes fine kindling for a hard coal fire and is 

 espeoially good to wake up such a fire quickly 

 without shaking down the furnace. If a few 

 blocks of peat are thrown on top of the fire and 

 the draughts opened, surprising results are ob- 

 tained. 



Too much of this fuel should not be put on at 

 a time. Peat is about twice as bulky as coal and 

 can not be transported long distances at a price 

 that is economical, but it does offer a good emer- 

 gency substitute for coal and is especially useful 

 as a supplementary fuel for use with coal. 



OYSTER CHANGES SEX THREE TIMES A 

 YEAR 



Science Service 



The remarkable and long disputed changes in 

 the sex of the edible oyster are settled by re- 

 searches of Dr. J. H. Orton, of the British Marine 

 Biological Association at Plymouth, and Dr. E. 

 Sparck, of the Danish Biological Station at 

 Limfjord. Working independently, both these 

 naturalists announced that these bivalves may be 

 male, then female, then male again all within one 

 year. The rate of change, Dr. Sparck believes, 

 depends largely upon the temperature of the 

 water. 



The oyster either never has possessed, or more 

 probably has discarded, all the trappings of sex. 

 There is a single genital gland and a single duet. 

 At one time male cells are produced and dis- 

 charged into the sea-water in clouds. At another 

 time egg cells are produced and are fertilized by 

 male cells drawn in from the surrounding water. 



There is no difference in the external appear- 

 ance of the oyster in its male and female phases, 

 although if the shells be opened, microscopical 

 examination of the sexual gland shows the dif- 

 ference between mobile sperm cells and the large 

 inactive egg cells. When it is sexually mature 

 for the first time the oyster ds ■ male. Next, after 

 a varying period, it becomes a female, and very 

 soon after the discharge of the embryos it again 

 begins to liberate male cells. One oyster has been 

 known to change three times in a single season. 



Dr. Sparck, however, thinks that the duration 

 of the male stage depends on the temperature. 

 The colder it is the longer the male stage lasts. 



The oysters in Southern Europe have been found 

 to begin breeding at an earlier age than those of 

 Northern Europe. Oysters in the northern waters 

 can produce young only every third or fourth 

 year, and therefore only three or four times in 

 their whole life. 



USEFUL POWDERS FROM WASTE LIQUIDS 

 A. C. S. News Service 



The atomizer has gone into business for itself 

 and is making big dividends out of wastes. Such 

 evil-looking liquids as the greasy waters from 

 fish oil plants, waste sulfite liquors from paper 

 mills, and the waters in which raw-wool has been 

 washed, yield wealth when forced through the 

 atomizer. 



Walter H. Diekerson, a member of the New 

 York Section of the American Chemical Society, 

 gives a description of the recently invented ma- 

 ahinery which reduces materials from a liquid to 

 a dry powder condition. The process is described, 

 briefiy, as one of "reducing the material to be 

 dried to a finely divided state by spraying or 

 atomizing; exposing the spray to heated air or 

 gas and quickly effecting the evaporation of the 

 moisture contents. ' ' 



Mr. Diekerson believes that some day the Chi- 

 cago Eiver may be run through such a machine, 

 to the greater beauty of the stream itself and to 

 good economic advantage. "Indeed, this would 

 be entirely possible and advantageous, ' ' said he, 

 ' ' if tihe waste heat that escapes up the flues of 

 manufacturing plants in the industrial distri&t of 

 Chicago near the river could be utilized for dry- 

 ing operations. ' ' 



In paper manufacture, chemists have found, 

 only about fifty per cent, of the wood used in 

 making pulp goes into the paper. The remaining 

 portion of the wood passes off in the waste waters 

 from the plant. Analyses showed that these 

 waste waters contained high proportions of 

 lignin — ^the adhesive material in wood. This is 

 not required in paper but is very useful for the 

 making of binders — cores for use in making molds 

 used in foundries, and in making coal briquettes. 

 The spraj drying process makes the recovery of 

 the lignin a profitable 'operation. 



The waste waters from fish oil plants yield 

 materials good for fertilizer and for poultry food. 

 Waste waters from wool cleansing plants give 

 grease, nitrogen and potash. Other industrial 

 uses of the process include a new method of 

 making starch, in that it can be reduced to the 

 form of fine powder, through the atomizer and 



