476 



♦ KNOWLEDGE ♦ 



[Dec. 12, 1884. 



crepancies. A host of men, theologians and otherwise, are 

 ever ready to denounce scientific teachings on such grounds. 

 The trouble is that there is no avoiding their denunciations. 

 Those of the milder sort deny that they are troubled be- 

 cause of such objections as the more virulent and foolish 

 are ever ready to raise. But they swell the cry of the 

 opponents of science all the same. Dr. Healy may take 

 exception only to our review of the sillier anti-scien- 

 tific works as implying that the writers of such 

 works are theologians instead of the dolts and ignora- 

 muses he perceives them to be ; or he may only 

 be troubled because a writer on science (who may 

 have given this particular point much more careful study 

 than ninety-nine out of a hundred clergymen) speaks of 

 the Books of the Pentateuch as assuredly not written by 

 Moses (as if by the way tfds were in any sort or degree a 

 theological question ; and as if it had not been shown by 

 men who have thoroughly studied this archa;ological subject, 

 that Moses could not possibly have written those books as 

 they stand). But his objections come in company with 

 those of multitudes of persons whom we could not possibly 

 satisfy, even though we could satisfy Dr. Healy. Why, I 

 have been publicly objurgated for teaching that the stars 

 are suns lying in the midst of infinity (or what to us is 

 practically infinity) of space, in all directions around us — 

 for no better reason than that in one of the books of the 

 bible we are told that the heavens are God's throne and the 

 earth His footstool (a statement which, so understood, 

 would require us further to believe that over Edom God 

 had cast out His shoe). By quite a large number I have 

 been asked whether it is not irreligious to accept the 

 teachings of astronomy, when, if accepted, they leave no 

 place for heaven, or for hell either, — an interpretation of 

 bible phrases which would leave it rather difiicult to 

 explain what was intended by the statement that to 

 produce the flood " the windows of heaven were opened." 



It has only been in this sense, or rather through such 

 nonsense as this, that anything in the slightest degree anti- 

 theological can ever be said to have appeared in the 

 columns of Knowledge. Any man can accuse a writer of 

 being anti-theological who chooses to start a theological 

 school of his own, and to say that the teachings of science 

 about God's universe are inconsistent with his own narrow 

 ideas respecting the domain and the power of the Almighty. 

 Any one can educe from his own nature conceptions of 

 what God is and how God acts ; and because his own 

 nature is small and spiteful, or cruel and despotic, or con- 

 ceited and overbearing, may denounce the ever-widening 

 range over which Science extends its survey — seeing God in 

 all and through all, too great to be within our ken, too 

 powerful for us to be able even to conceive His might, too 

 "Wise for us to follow the workings of His mind. His 

 Infinite Comprehension of all things that are and have 

 been and will be throughout Eternity. But Science 

 has nothing to fear from such attacks. Her business 

 is to study God's universe without fear or anxiety, 

 lest suddenly she should discover soniething mean 

 or unworthy therein. She cannot fear lest " some hysteric 

 sense of wrong or insult should convulse the throne 

 where Wisdom reigns supreme." When She is told to take 

 the shoes from off her feet because the ground on which she 

 treads is holy ground. She answers that God's whole domain 

 is holy to them that rightly think of it ; not this thought 

 or that feeling, but all our thoughts and all our feelings 

 about the universe should be full of reverence, because all 

 things— the great and the small, the long-lasting and the 

 short-lasting — are full of mystery, instinct with infinite 

 wonder. In the words of the science poet, Goethe (quoted 

 to this effect by one of those most roundly denounced 



by men regarding themselves absurdly as defenders of 

 religion) : — 



Gleams across the mind His light 



Feels the lifted soul His might : 



Wlio then dare deny His right 

 The AU-Eufoldcr ? 



Who dare to name His name, 

 Or belief in Him proclaim — 

 Clothed in mystery as He is, 

 The AU- Upholder? 



PLEASANT HOURS WITH THE 



MICROSCOPE. 



By Henet J. Slack, F.G.S., r.E.M.S. 



I AM often asked to advise intending purchasers of micro- 

 scopes what they should look for, and the question is 

 just now very seasonable, as many parents are anxious to 

 make a really useful and handsome Christmas present to 

 their sons and daughters. No intelligent family should be 

 without a microscope, but the size and sort should be 

 decided by the use likely to be made of it. Medical 

 students find a small, strong, portable instrument of 

 simple structure the most useful for following histological 

 demonstrations, and the powers recommended as essential 

 are 1 in., ] or J in., with two eye-pieces. Instruments of this 

 sort cost from £5 to £G or £7, and they suiEce for ordi- 

 nary purposes ; but they are not adapted either for the 

 best display of beautiful objects or the exhibition of diffi- 

 cult ones. Many English makers follow French and 

 German patterns, and give their microscopes short tubes. 

 This is handy for a student's rough use, but for steady, 

 quiet work the English tube length of about nine inches is 

 to be preferred. It is brought up to ten inches when the 

 objective is added. The length of the tube determines the 

 amount of magnification to be obtained with a given eye- 

 piece and objective. The longer the tube the greater 

 the power, and many instruments are made with draw- 

 tubes for the purpose of obtaining this advantage to a 

 greater extent. It is chiefly applicable to the lower powers, 

 as with a quarter and upwards the performance is injured 

 unless the objective is used with the tube-length best suited 

 to it. In buying foreign high-powers this should be 

 thought of. 



A microscope that can only be used in a vertical position 

 is not desirable, as looking through it keeps the head in 

 an uncomfortable and wearisome attitude. For prolonged 

 observation a horizontal position is the best, but for common 

 purposes the tube may slant at about 45 deg. 



The range of movement given to the tube for focussing 

 varies with diflferent patterns. The best instruments allow 

 a 4-inch objective to be used for large olijects, and so much 

 pleasure and information can be obtained with this low 

 magnification that it is well to require a stand that will 

 permit its employment. 



The amount of magnification obtained with various eye- 

 pieces and objectives is reckoned by comparison with their 

 apparent linear dimensions as seen by a sound and normal 

 eye without any assistance at ten inches' distance. The terms 

 four-inch, one-inch, quarter-inch, itc, mean that the com- 

 pound lenses of the objective magnify as much as simple 

 ones of the.'e focal lengths. 



The cheapest form of microscopes has a simple up and 

 down movement of the slide-holder. A better and more 

 expensive sort enables the slide-holder to be readily moved 

 in any direction, and with best instruments there are two 

 rack and pinion motions at right angles to each other. 

 This is very handy, but not essential even for delicate 



