€J)e popular Science iSetPS 



AND 



BOSTON JOURNAL OF CHEMISTRY. 



Volume XXII. 



BOSTON, JUNE, 1888. 



Ndmbee 6. 



CONTENTS. 



Familiar Scienck. — Care in Experimenting 81 



Artificial Rubiee 81 



Matter made Invisible, but not Lost 82 



Simple Scientific Experimcuts 82 



An Eigbt-Hour Day 83 



Magnetic Suggestion 83 



Transatlantic Glances 84 



Scientific Brevities 84 



Practical Chemistry and the Arts. — Sulphuric Acid, So 



Some Notes on tbe Use of Kerosene as a Fuel 85 



The Separation of Tin from Antimony 86 



An Application of Static Electricity 86 



Industrial Memoranda 8G 



Home, Farm, and Garden. — The Japanese Wax-Tree. ... 87 



The Chemistry of the Beehive 87 



Honey Production in California 88 



Gleanings 88 



Editorial. — Science in the Bacon-Shakespeare Controversy, 89 



Paris Letter 90 



The Oldest Roclis 91 



Astronomical Phenomena for June, 18S8 91 



Meteorology for April, 1888 92 



Questions and Answers 92 



Literary Notes 92 



Medicine and Pharmacy. — Tbe Mind Cure 93 



Monthly Summary of Medical Progress 93 



Some Facts concerning Bright's Disease 94 



The Infliction of tbe Death Penalty by Electricity 95 



Buttermilk as a Medicine 95 



The Prognosis of Various Diseases 96 



Drug-Stores in Germany 96 



How to Treat Cramps in the Leg 96 



POBLISHERB* COLUHN 96 



JFamUiac S)(Uiue. 



— ~- -•- — 



CARE IN EXPERIMENTING. 



There comes a time in the life of many boj"8 

 when a passion for performing chemical ex- 

 periments develops itself; and if there is no 

 convenient out-building to serve the purpose 

 of a laboratory, the lives of the other mem- 

 bers of the family are rendered miserable by 

 nauseous and suffocating odors, and apprehen- 

 sions of dangerous explosions which are not 

 infrequently realized. 



The study of chemistry is a most fascinat- 

 ing and delightful one ; but it must be remem- 

 bered that at the very beginning we have to 

 deal with powerful substances, which require 

 to be handled with great care, or the most 

 unpleasant consequences may ensue. Man}- 

 elementary text-books of chemistry are, we 

 think, seriously at fault in not giving more 

 attention to the precautions necessary in the 

 experiments which they describe. Under the 

 supervisionof a competent instructor, the young 

 student is taught how to take these precautions : 

 but in a large class of pupils, personal atten- 

 tion cannot be given to every one ; and if the 

 enterprising amateur attempts to repeat the 

 experiments which succeed so well under the 

 manipulations of the teacher, it is more than 

 probable that some little point will be over- 

 looked which may involve the entire difference 

 between danger and safety. 



Perhaps the most common of all experi- 

 ments is the making of hydrogen gas ; this is 

 usually done by placing pieces of zinc in a 

 glass flask fitted with a cork and delivery 

 tube, and pouring in dilute sulphuric acid. 

 The hydrogen escapes from the end of the 

 delivery tube, where it is ignited. This is ap- 

 parently simple enough ; but the beginner in 

 chemistry usually forgets that hj-drogen and 

 air mixed together form a very explosive mix- 

 ture, and attempts to ignite the hydrogen be- 

 fore it has entirely displaced the air in the 

 flask. A violent explosion ensues, throwing 

 the acid and fragments of glass in all direc- 

 tions, not infrequently causing serious injury-. 

 A student in a New-England college was terri- 

 blj- injured rccenlh- by the explosion of a glass 

 flask in which he was preparing carbonic-acid 

 gas; the delivery tube becoming obstructed, 

 and the pressure of the confined gas causing 

 an explosion. 



An experiment frequently given in text- 

 books is to rub a few grains of chlorate of pot- 

 ash and sulphur together in a mortar, when 

 slight explosions will occur. Unless very 

 small quantities are used in this experiment, 

 the explosion is likely to be any thing but 

 " slight ;" but this point is rarely noticed with 

 sufficient emphasis. We know of a case 

 where a youthful chemist attempted to "im- 

 prove " upon this experiment, by substituting 

 phosphorus for sulphur. The mixture was 

 made up into " torpedoes," and placed in his 

 pocket for safe keeping. By good luck, the 

 explosion which resulted did no serious injury ; 

 but the consequences might have been fatal. 



A recent number of a leading educational 

 journal suggests, as an experiment to illustrate 

 the expansive power of steam, the explosion 

 of " candle-bombs ;" i.e., small glass bulbs 

 containing water, and hermeticallj' sealed. 

 From personal experience with a home-made 

 candle-bomb, we think we should prefer to fire 

 a gun in a room filled with scholars, rather than 

 to attempt to explode one of these miniature 

 infernal machines ; but nothing was said in the 

 journal above mentioned to indicate that the 

 experiment was accompanied bj* the slightest 

 danger. 



A number of experiments with phosphorus 

 are usually given in elementary text-books, all 

 very brilliant and beautiful ; but phosphorus is 

 a substance which should nevfer be handled by 

 inexperienced persons. It is a treacherous 

 and dangerous element at the best. 



We could give many more examples similar 

 to the above, but enough has been said to 

 show that the beginner in chemistry should 

 confine himself to experiments that are free 

 from, all possibility of danger, such as are 



frequently given in our columns, unless he has 

 some experienced friend or teacher to warn him 

 against unforeseen emergencies. Of course, 

 to obtain any complete knowledge of the 

 science one must handle both explosive and 

 poisonous substances ; but the probable danger 

 must always bo borne in mind, and if no per- 

 sonal instruction can be obtained, the risk 

 should be reduced to a minimum b}- working 

 with the smallest possible quantities. 



ARTIFICIAL RUBIES. 



OiiR readers may liave lately seen reported 

 the success of two French chemists, MM. 

 Fremy and Verneuil, in producing by artificial 

 means rubies of considerable size, which in 

 all their chemical and physical characteristics 



cannot be distinguished from the natural prod- 

 uct. So close is this resemblance, that the 

 French jewellers have agreed not to recognize 

 these artificial gems as of any value, and 

 penalties have been provided for attempts to 

 sell them for the genuine article. 



The natural ruby is simpl3- crystallized co- 

 rundum, or oxide of aluminium (AI2O3), with 

 a trace of coloring- matter, probably chro- 

 mium. The rubles produced by the French 

 chemists were made bj- heating to redness 

 ordinary alumina containing a little bichro- 

 mate of potash with certain fluorides, par- 

 ticularly fluoride of barium. The crystals of 

 alumina are formed throughout the gangue, as 

 shown in Fig. 1, from which they are com- 

 pletely removed by simply washing with water. 



The rubies thus formed (Fig. 2) have the 

 color, hardness, lustre, crystalline form, and 

 chemical composition of the natural gems 



