568 



THE POPULAR SCIENCE MONTHLY. 



The swimming bladder of ordinary fishes has 

 been modified so that it serves as a lung. In 

 Africa, JProtopterm, a form closely allied to 

 Ceratodus, makes for itself a cocoon of mud, 

 in which, during the hot, dry season, it lives, 

 and can breathe by means of its lung. The 

 Ceratodus does not appear to do this, and 

 probably never leaves the water. It comes 

 continually to the surface, and passes out 

 and takes in air, making a faint spouting 

 noise. The author suggested that the lung 

 was of the greatest service to the animal, not 

 during the hot but during the wet season, 

 when the rivers are flooded and the water is 

 thick with sand. The Ceratodus appears to 

 be herbivorous, and feeds largely on the 

 seeds of gum trees which fall into the water. 



Dealing with Contagions. A report by 

 Dr. A. Jacobi calls attention to some pecul- 

 iar difficulties in dealing with the contagion of 

 scarlet fever and diphtheria. No general hos- 

 pital must admit patients suffering from either 

 disease. Hotel-keepers are not willing to ad- 

 mit them ; but if cases get lodgment within 

 their houses, it is to their interest to conceal 

 the fact. Their interest, however, does not go 

 so far as to induce them to destroy or disin- 

 fect curtains and carpets, and purify the 

 walls of rooms, and the contagion is perpetu- 

 ated. Rooms and suites of rooms in large 

 and expensive hotels are known in which 

 cases of diphtheria have occurred for several 

 years in succession, all provoked by the same 

 germ, lodged in the same curtains and car- 

 pets. The same danger lurks in private 

 houses, where the well members are impei'- 

 iled by the presence of the sick one, and all 

 the surroundings are liable to be infected; 

 and in tenement-houses, where close contact 

 of the well with the sick can hardly be avoid- 

 ed. Patients should be removed from homes 

 and hotels and isolated ; but this is impossi- 

 ble, for the want of provision for the proper 

 care of such cases. The only institution for 

 these diseases in New York is the Willard 

 Parker Hospital, which is in a remote part of 

 the city, and has beds for only seventy pa- 

 tients, while twenty-five hundred persons 

 die annually of the infections. Plans for 

 new hospitals are proposed by the Medi- 

 cal Society of the City of New York, and 

 with them stations or refuges, where the chil- 

 dren of families in which diphtheria or scar- 



let fever is prevailing can be housed until 

 the patients at home have recovered or been 

 removed, and their residences, bedding, and 

 furniture have been thoroughly disinfected. 



Treatment of Potato Disease. The treat- 

 ment of potato disease with sulphate of cop- 

 per has been found efficacious at Nantes, 

 France. A dressing of three pounds of sul- 

 phate of copper to twenty gallons of water, 

 or of two pounds of sulphate of copper and 

 four pounds of lime to twenty-five gallons of 

 water, is used. The best results are obtained 

 by using whole potatoes, sound, of medium 

 size, selecting those which show the finest 

 germs, and cutting very large ones in two. 

 Before planting they are steeped for twenty- 

 four hours in a bath composed of six pounds 

 each of sulphate of ammonia and nitrate of 

 potash and twenty-five gallons of water ; then 

 allowed to stand twenty-four hours to give 

 the sprouts time to swell whereby the growth 

 is quickened and the return is increased. Dis- 

 ease in tubers is arrested by dipping them in 

 a bath of water and as much lime as it will 

 take, and drying them. The diseased part 

 seems to solidify after this treatment, and 

 does not spread, while the good part con- 

 tinues sound. 



Propagation of Fine Flower Seeds. 



From an address by Mr. George F. Daniels, 

 quoted in Garden and Forest from the Jour- 

 nal of Horticulture, we learn that the in- 

 creased demand for flowers in England and 

 America has given a corresponding impetus 

 to seed-growing abroad, where they have the 

 advantage of cheap labor and a climate es- 

 pecially adapted to the work. The secret of 

 successful cultivation in Germany lies in the 

 bright, dry autumn, which enables seeds to 

 stand longer and become more thoroughly 

 ripened. The soil is also well adapted for 

 the purpose. Stocks are one of the most ex- 

 pensive crops, in the item of labor, because 

 the finer varieties have to be grown in pots, 

 and they require attention in watering. China 

 asters are grown by acres, one firm devoting 

 more than a hundred acres to them. Petu- 

 nias require much attention, as each bloom 

 has to be fertilized by hand to insure the 

 setting of the seed. The pollen from the 

 double blooms is very difficult to obtain, the 

 flowers being so dense that they have often 



