FRAGMENTS OF SCIENCE. 



573 



elevation of four thousand feet extends ap- 

 proximately over an area of twenty-six thou- 

 sand five hundred square miles, while an- 

 other seventy two thousand five hundred 

 square miles may be added which lie be- 

 tween three thousand and four thousand 

 feet. The country has suffered much of re- 

 cent years, with all South Africa, from rin- 

 derpest, locusts, and drought, but more fa- 

 vorable conditions are hoped for, and with 

 them anything can be grown that can be 

 grown in Cape Colony. Wheat and oats, 

 however, will have to be raised in the dry 

 season with irrigation. For markets the 

 farmer must look to the local towns, and 

 their growth will depend upon the develop- 

 ment of the gold prospects; and a wider 

 market awaits the stock farmer. Matabele- 

 land has been demonstrated to be a good 

 cattle country. The natives formerly pos- 

 sessed considerable herds of sheep and goats, 

 but these were killed and eaten during the 

 scarcity of food. Sheep, however, seem to 

 thrive well, as do pigs and donkeys. Well- 

 bred fowls are subject to much disease, and 

 the native birds are very small and lay 

 small eggs. Horses do badly in all parts of 

 Rhodesia. The speaker did not look upon 

 the land as a ready-made paradise. Such a 

 spot is hardly to be found in the unoccupied 

 world ; but " the earthly paradise of a happy 

 home in a wild land must be created by a 

 man's own labor, patience, intelligence, and 

 perseverance." 



Liquefied Fluorine. — The much-sougbt- 

 for alkahest, or universal solvent of the an- 

 cient alchemists, is almost realized in fluo- 

 rine, which was first prepared by Moissan in 

 1886. The transparent vessels iu which it 

 is contained have to be made of some fluo- 

 ride, its action on ordinary glass being vig- 

 orous and destructive. The difficulty of 

 handling the gas, even in the laboratory, has 

 hence been very great, the fluoride vessels 

 being brittle and clumsy as well as expensive. 

 Professors Dewar and MoissaD, being desir- 

 ous of more fully investigating the properties 

 of the gas, recently conducted a series of ex- 

 periments at the Royal Institution, in which 

 by means of liquid oxygen they succeeded 

 in liquefying fluorine, and in this compara- 

 tively inert state could more fully and care- 

 fully examine its properties. The apparatus 



used for liquefying the gas consisted of a 

 small cylinder of thin glass, into the upper 

 part of which was fused a platinum tube 

 surrounding a smaller tube of the same ma- 

 terial. The fluorine enters through the 

 larger tube, passes around the glass envelope, 

 and escapes through the smaller tube. The 

 glass cylinder being cooled down to the tem- 

 perature of boiling liquid oxygen (— 183°), 

 the current of fluorine gas was passed through 

 the bulb without becoming liquid ; at this 

 low temperature, however, the fluorine did 

 not attack the glass. On still further lower- 

 ing the temperature of the liquid oxygen, by 

 exhaustion, a yellow liquid was seen collect- 

 ing in the glass envelope, while gas no longer 

 escaped from the apparatus. At this mo- 

 ment the escape tube was closed to prevent 

 the entrance of air, and the glass bulb soon 

 became full of a clear yellow liquid possessed 

 of great mobility. Fluorine thus liquefies at 

 about — 185°. The chemical activity of the 

 gas was found greatly reduced when in the 

 liquid state, but even then benzene or oil of 

 turpentine underwent spontaneous decompo- 

 sition when brought into contact with it. It 

 would thus seem that the powerful affinity of 

 fluorine for hydrogen is the last to disappear. 

 In a subsequent experiment, in which liquid 

 air was used and a temperature approxi- 

 mating — 210' obtained, the liquid fluorine 

 showed no signs of solidification. Experi- 

 ments to determine its density led to the 

 conclusion that it had about the same spe- 

 cific gravity as amber, T14. Different sam- 

 ples of the liquid examined with the spectro- 

 scope showed no specific absorption bands in 

 the visible spectrum. It was found to be not 

 magnetic. 



Monazite. — Much has been said of late 

 years, in discussions concerning the "rare 

 earths " and the search in them for new 

 metals, about monazite ; and the mineral has 

 obtained considerable commercial importance 

 in consequence of its use in the manufacture 

 of the incandescent mantles of the Welsbach 

 light. Monazite, as described by H. B. C. 

 Nitze in the Franklin Institute, is essentially 

 a phosphate of the rare earth metals cerium, 

 lanthanum, and didymium. It also usually 

 contains small variable percentages of thoria 

 in the form of thorite or orangite — a deriv- 

 ative of another rare metal, thorium. It 



