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THE POPULAR SCIENCE MONTHLY. 



DisinToction by Iloat and by Steam. — 



Dr. II. F. Parsons has found, in experi- 

 ments on tlie disinfection of pacliages by 

 heat and by steam, that dry heat at the 

 boiling-point for an hour is suflicient to 

 destroy active bacilli of all ordinary infec- 

 tious diseases ; but, if spores are to be at- 

 tacked, a heat of 215° for an hour or of 

 220° for four hours will be required. The 

 complete penetration of an object by steam- 

 heat for more than five minutes is sufficient 

 for its full disinfection ; and this method is 

 applicable to such articles as pillows, which 

 are very difficult of ptnctration to dry heat. 

 Moistening the air of the heated chamber 

 diminishes the time necessary for penetra- 

 tion, while it also makes the distribution 

 of temperature through the chamber more 

 agreeable, and tends to prevent the scorch- 

 ing of articles placed in it ; but it was not 

 found to increase the disinfecting power at 

 the temperature employed. Damage may 

 be done to articles in disinfecting them by 

 heat or steam, by scorching or partial de- 

 composition of organic substances ; by fix- 

 ing of stains ; by melting of fusible sub- 

 stances ; by changes in color, gloss, etc. ; by 

 shrinking and felting of woolen materials; 

 or by wetting. The nature of the articles 

 should, therefore, be regarded in adapting 

 the process to them. 



English Taxes, — The first recorded tax 

 imposed upon Britain was laid by Julius 

 Ca-sar, who, after his victories, required for 

 Rome an annual tribute of men and wild 

 animals — the men to be kept as hostages, 

 the animals to be fought with in the arena. 

 When ecclesiastical domination came in, the 

 Pope levied a "Peter's pence" for the sup- 

 port of his English University at Rome. 

 When the English conquered Wales, they 

 levied on the people an annual tax of three 

 hundred wolves' heads, which proved a great 

 blessing to the principality. After England 

 became exposed to great danger from the 

 incursions of the Northmen, a land-tax of 

 twelve pence per " hide " was levied in or- 

 der to raise a sum with which to buy off 

 the invaders. Tlic consequence of this silly 

 policy was that more invaders came to be 

 bought off. A poll-tax was imposed in the 

 fifteenth century of one shilling a year upon 

 every person, except he belonged to the 



clergy, above the age of fifteen years. This 

 was distasteful to the people, and led to re- 

 bellion. In another form of taxation, la- 

 borers and tradesmen were required to give 

 their services to the king or to a noble. 

 Many palaces, Windsor Castle among them, 

 were built in this way. From 1G95, for 

 thirteen years, every person not a pauper 

 was required to pay a tax for each child 

 born to him, rising from two shillings in 

 the case of a common person to thirty 

 pounds in the case of a duke. A bachelor's 

 tax of one shilling in the case of ordinary 

 persons was imposed on unmarried men 

 over twenty-five years old, and on widowers 

 without children, but wealthy people and 

 nobles had to pay more. By Queen Eliza- 

 betlj's act of uniformity, persons who re- 

 fused to become Episcopalians, or who ab- 

 sented themselves from church on Sundays, 

 had to pay a tax of a shilling a ytar. Per- 

 haps the most oppressive and impolitic taxes 

 imposed by the British Government were 

 those on windows and on funerals, with 

 which even the history of this nineteenth 

 century has been blotted. 



NOTES. 



The second ten days of January were 

 extraordinarily cold all through the North- 

 west, and temi)cratures were registered at 

 some places much below what had ever be- 

 fore been observed in the United States. 

 At Iowa City, according to Professor Ilin- 

 richs, the mercury was at or below zero 

 every night from the 11th to the 20th. 

 During the twenty-eight years that weather 

 observations have been taken, there have 

 been only five decades having a mean tem- 

 perature of zero or below ; only one of these 

 was during the first eighteen years, while the 

 other four were during the last ten years. 

 This shows that extreme cold has been seven 

 times more frequent during the latter than 

 during the former years, and is another in- 

 dication of what the author has often held, 

 that the later winters in Iowa have been 

 colder than the former ones. 



A "carle anchor" has been success- 

 fully tried in the Seine for stopping boats. 

 The rpparatus is a cable, having on it a sc- 

 ries of canvas cones, which open out by the 

 action of the water, and close again when 

 drawn the usual way. A steamer running 

 thirteen knots was stopped each time by the 

 apparatus in thirteen seconds, and in a 

 space of from twenty to thirty feet. 



