Their utility and importance to the cause of education need not, we are sure, be insisted upon, when it is understood that any child can be furnished with a perfect globe at a price to come within ordinary means. When used they are inflated with air, and when collapsed, may be folded in so small a compass as to be no incumbrance under any circumstances. When the large sizes are filled with hydrogen they become highly ornamental and beautiful objects. CHAPTER V. ADULTERATION OF INDIA-RUBBER—(Caoutchouc.) Every article of commerce that is susceptible of adulteration is sure to fall into the hands of those who seem to be peculiarly educated to the work of diluting, and reducing by various chemical processes the real value of the article to be counterfeited. No matter how cheap the pure substance can be obtained, some method must be conjured up by which the innocent purchaser or consumer is unconsciously duped. India-rubber and gutta-percha are among the vegetable gums, which have been _most extensively_ adulterated. It long since became a matter of scientific research in England, to ascertain how great a per cent. India-rubber could be reduced, by the admixture of worthless compounds, and the same skill has been thus perverted in our own country. In Prussia, a law was passed in 1856, making the adulteration of chemicals and articles of consumption by which life shall be endangered, an offence punishable with death. The simple adulteration of food or drink with any deleterious substance, is punishable with fifteen years’ hard labor; and any other adulteration is regarded as cheating (betrug), and is punished accordingly. However severe or stringent these laws may seem to a republican mind, they are nevertheless just. What is the sale of an adulterated article, but the obtaining of money under false pretences, and why should not every rude infraction of the law of right, be visited by some adequate penalty? A series of letters were published in 1856, in England, under the above caption, which shows very clearly the extent to which the practice of adulteration had then been carried. We herewith give the most important statement contained in those letters. The letters referred to were written by William H. Herbert, Esq., and addressed to the Editor of the London Mechanics’ Magazine.