Scientific.

Otago Witness, Issue 1243, 25 September 1875, Page 3

Scientific.

SCIENCE FOR THE PEOPLE. NATUKAI, LAWS.

If a man ever finds time to look up from his work, he may see that there is around him a wonderful creation, in every part of which there is motion and change, and every change is an advance towards something more perfect These changes take place with such order and regularity, that most people do not see that anything is happening ; it is ouly when you look closely into nature that you find all is activity, and there is nothing like stagnation anywhere. You had illustrations given in the lectures by Professor Roscoe that these changes which are always going on occur in perlect order, bo that under the same circumstances the same thing alway happens, and tlus is so strictly the case that they are said to be illustrations of natural law. Now these natural laws are of the greatest importance for us to understand. lam sure that you believe this so far as chemistry is concerned, for you have seen that we are able to make substances of great commercial value by taking advantage of these laws, and that the want of full knowledge of them may cause people to suffer greatly from injurious things, as from waste hydro-chloric acid, until it was got rid of in the formation of bleaching powders. I merely mention this to show that you are already acquainted with the importance of a knowledge of natural law. With regard to life vi connection with external circumstances, I shall not be able to show you so clearly the importance of a knowledge of the laws regulating these things ; but I think I can convince you of their importance by simply telling you what you know very well, -that your life and health are the most valuable things you p Oa3eS s ; anything, therefore, which will assist you to understand the laws which govern life and health m connection with external circumstances must be of the greatest value. Supposing a man becomes alive to what is going on around him, he will take a wide and extended view of this world upon which we are placed, and will see that it is a great round mass of solid substance hanging free in the heavens ; and, if seen from a distance, shining like a star. I will show you upon the screen a photograph of the moon, which will give you an idea of what will be the appearance of our earth if seen through ateletcope from some other pl ane t. l s how you the moon, because with every desire

to satisfy me and you, Mr Brothers was not able io fix his camera upon any place where he could photograph the earth. You will see it is a great round ball of solid substance, made uneven by mountains and valleys. If it were the earth, we should have upon it, in addition, a great body of water forming our oceans and seas, and above that there would be a layer of gaseous matter, which we call the air or atmosphere. We have on earth, then, illustrations on a large scale of three states in which material substances can exist, namely, the solid, the liquid, and the gaseous state. Now, though I cannot show you a true portrait of the earth, I will give you a picture of its shadow from which you may see that it is really globular. I will show you a photograph of an eclipse of the moon where the fshadow of the earth cuts off a portion of the full moon, and this shadow, as you may see, is cast by a round body. — Dr Alcoch's Lectures for the People.