76 



THE POPULAR EDUCATOR. 



jjlomb? 26. Non, Monsieur, j'ai un cncrier de porcelaiue. 27. 

 L'e'tranger a-t-il de la volaille ? 28. L'e'tranger n'a pas de volaille, mais 

 il a de 1'argent. 29. Votre frere a faim et soif, peur et sommeil. 30. 

 Quelqu'un a-t-il honte ? 31. Non, Monsieur, personne n'a honte. 32. 

 Votre frere a-t-il raison ou tort ? 33. Mon frere a raison, et le votre 

 a tort. 34. Votre so3ur n'a ni son chapeau de satin, ni son chapeau de 

 velours. 



EXEBCISE 15 (Vol. I., page 60). 



1. Have you the carpenter's hammers ? 2. We have the black- 

 smith's hammers. 3. Have the blacksmiths two wooden hammers ? 

 4. They have two iron hammers. 5. Have the generals your horses ? 

 6. No, they have their own. 7. My mother has her sister's gold and 

 silver jewels. 8. Have the children their toys and their birds? They 

 have not their birds, but they have their toys. 9. Has the black- 

 smith a pair of woollen stockings ? 10. The blacksmith has two pairs 

 of woollen stockings. 11. Sir, are you not cold? 12. No, Sir, I am 

 warm. 13. Have you coffee or chocolate ? 14. I have neither coffee 

 nor chocolate. 15. Have you not the cabbages of my large garden ? 

 16. I have the vegetables of your small garden. 17. What is the 

 matter with your son ? 18. My son has nothing. 19. Have you two 

 pieces of bread ? 20. The miller has a piece of bread and two barrels 

 of flour. 21. Has the grocer coffee, ta, chocolate, and pepper ? 22. He 

 has tea and coffee, and your merchant's chocolate and pepper. 23. Who 

 has money ? 24. I have no money, but I have paper. 25. Have you 

 good paper ? 26. I have bad paper. 



LESSONS IN CHEMISTRY. III. 



MEASURES USED IN CHEMISTRY. The French weights and 

 measures, which are on the decimal system, are universally 

 adopted in chemistry, on account of their simplicity. 



MEASURES OF LENGTH. 



Millimetre 



Centimetre 



Decimetre 



METRE 



Decametre 



Hectometre 



Kilometre 



Myriometre 



English Inches. 



'03937 



0-39370 



3-93707 



39-37079 



393-70790 



3937-07900 



39370-79000 



393707-90000 



MEASURES OF CAPACITY. 



Mfflilitre . 

 Centilitre . 



Decilitre .... 

 LITEE (a cubic decimetre) 

 Decalitre .... 

 Hectolitre .... 

 Kilolitre .... 

 Myriolitre .... 



In Cubic Inches. 



0-061027 



0-610271 



6-102705 



61-027051 



610-270515 



6102-705151 



61027-051519 



610270-515194 



Pints. 

 = 1-76 



MEASURES OF WEIGHT. 



English Grains. 



Milligramme '015 



Centigramme ..... 0'154 



Decigramme ..... 1'543 



GRAMME 15-4S2 



Decagramme ..... 154-323 



Hectogramme 1543'234 



Kilogramme 15432'348 



Myriogramme 154323-488 



A fcilogramma = 2 '2046 Ibs. avoirdupois. 



In verifying the following results by arithmetical calculation, 

 the student will impress on his mind this system of weights and 

 measures : 



1 inch = 2-539954 centimetres. 



1 foot = 3-0479449 decimetres. 



1 yard = 0'9143834 metre. 



1 mile = 1-6093149 kilometre. 



1 cubic inch = 16'3861 cubic centimetres. 



. 1 cubic foot = 28-31531 cubic decimetres. 



1 gallon = 4-54345 litres. 



1 grain = '06480 gramme. 



1 Troy oz. = 31 '103496 grammes 



1 Ib. avoir. = 0-45359 kilogramme. 



1 cwt. = 50-80237 kilogrammes. 



The whole of the above system is founded on the " metre," 

 which measure was originally intended to be ^^QQ of the 

 distance along a meridian from the equator to the pole. But 

 since the " metre " was thus fixed, an error has been discovered 

 in the measurement of the earth, and now a " standard " metre 

 is kept in Paris. 



The measures of weight are connected with those of length 



Fig. 1. 



through the gramme, which is the weight of 1 cubic centi- 

 metre of pure water, taken at the maximum density of water, 

 a temperature of 4 Centigrade, and weighed at Paris. 



THERMOMETRT. 



Heat is "that which produces in us the sensation of warmth." 



Temperature is " that energy with which one body seeks to 

 impart its heat to another.'' 



Thus the temperature of a body is no indication of the real 

 quantity of heat in the body. Equal weights of mercury and 

 water may have the same temperature, and yet the water will 

 contain really thirty times more heat or caloric than the metal. 



Thermometers are measurers of " temperature," not of heat 

 High temperatures are measured by pyrometers ; extremely low 

 temperatures by alcohol thermometers; while mercurial ther- 

 mometers are used for the intermediate ordinary temperatures. 



These instruments depend for their action upon the 

 fact that all bodies, with the rise and fall of their 

 temperatures, expand and contract. In pyrometers 

 (Fig. 1), a small bar of platinum, s, which can only be 

 melted by the intense heat of the flame of the oxy- 

 hydrogen blowpipe, is placed in a hole, b b, drilled 

 in a piece of graphite, o, a form of carbon which is 

 capable of supporting any heat. The bar projects 

 above the hole, and is bound to the graphite _ a 

 piece of which has been sliced away to expose the 

 hole by a platinum strap, a. The position of the 

 top of the bar is carefully noted. It is now intro- 

 duced into the furnace whose temperature is required. 

 The bar expands, and when it is removed, the strap 

 prevents it from resuming its former position. Thus 

 the expansion of the platinum is found, and from 

 experiment we have learnt that for every 1 00 Cent. 

 platinum expands ^ of its length, and therefore we 

 can calculate the heat of the furnace. 



Mercury is chiefly used for thermometers for five reasons : _ 



1. It is easily got pure, for mercury can be distilled like 

 water. 



2. It does not stick to the glass. 



3. It has a long range, freezing at 40 Cent., and boiling 

 at 350 Cent. 



4. It expands uniformly that is, it increases as much in bulk 



if heated from 50 to 60, as it 

 will from 150 to 160. 



5. Having a low " capacity for 

 heat," its temperature soon 

 changes; it is, therefore, very 

 sensitive. 



TO MAKE A MERCURIAL THER- 

 MOMETER. 



1. Take a glass tube with a ca- 

 pillary bore (fine, "like a hair"), 

 as represented at A in Fig. 2 ; 

 make about half an inch of mer- 

 cury run down it, and measure it 

 at different points in its descent. 

 If it retain its length, the bore 

 is uniform. 



2. Blow the bulb, B, not with 

 the mouth, lest moisture be intro- 

 duced, but by connecting the tube, 

 by an india-rubber pipe, with a 

 bag of the same material, and 

 then pressing the bag while the 

 end of the tube is held in a gas 

 flame, as hereafter to be described. 



3. Fasten a funnel of paper, c, 

 to the top of the tube, and put 

 into it some purified mercury; 

 now heat the bulb, and the air 



expanding will bubble through it. Upon removing the lamp, 

 the air will contract, and the mercury will be forced into the 

 bulb. Eepeating this process a few times, the bulb and tube 

 will be filled. The lamp flame is again applied to the bulb, and 

 while the mercury is oozing out, the tube is hermetically sealed, 

 by bringing a blowpipe flame to play upon its open end. 



4. Thermometers are graduated according to three scales. 



Fig. 2. 



