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AND 



BOSTON JOURNAL OF CHEMISTRY. 



Volume XXII. 



BOSTON, APRIL, 1888. 



Number 4. 



CONTENTS. 



Familiar Science. — The Limitations of our Knowledge . . 49 



On the Study of Nature 49 



The Making of the " Origin of Species " 50 



Botany as a Recreation 51 



Ferns .' 52 



Scientific Brevities 52 



Practical Chemistbt and thb Arts. — Platinum 53 



Preparation of Peroxide of Hydrogen on a Large Scale ... 53 



Scientific Kailroad-Building 53 



A Simple Thermoscope 54 



Electric ** Sunstroke" 54 



A Much-Needed Invention 54 



Chemical Notes 54 



Practical Recipes — 54 



Home, Farm, and Garden. — The Growth and Decay of 



Rocks 55 



Stable Management 55 



Selected Recipes 56 



Care of Lamps 56 



Gleanings 56 



Editorial. — An Ancient Japanese Fort 57 



Recent Feats in Photography 58 



Paris Letter 58 



Meteorology for February, 1888, with Review of the 



Winter 59 



Astronomical Phenomena for April, 1888 59 



Where did they Come from? .'. 60 



A Curious Electrical Phenomenon 60 



Questions and Answers 60 



Literary Notes 60 



Medicine and Pharmacy. — The Natural Food of Man... 61 



"The Catarrh" 61 



Monthly Summary of Medical Progress 62 



Medical Misceil.iny 63 



Patent Medicines 64 



Medical Memorandft 64 



Humors 64 



Publishers' Colukh 64 



f amiltac Sittente. 



THE LIMITATIONS OF OUR KNOWLEDGE. 



In the wonderful advance of scientific knowl- 

 edge during the last hundred j'ears, we are 

 likely to overlook the many fundamental laws 

 and phenomena of the natural and physical 

 world of which we still remain in utter igno- 

 rance. We pluck the fruit from the wide- 

 spreading branches of the tree of knowledge, 

 but its roots remain hidden from our sight. 

 The action and effects of the forces of nature 

 are constantly becoming more and more famil- 

 iar to us, and it is on this line that most of our 

 progress has been made ; but as to the nature 

 of the forces themselves we are still ignorant. 



The constitution of matter has been a sub- 

 ject of dispute from the time of Aristotle, and 

 it is not too much to sa}- that we have no more 

 absolute knowledge on this point than had 

 Aristotle himself. Starting from the suppo- 

 sition that matter is not continuous, but made 

 up of disconnected atoms or particles of defi- 

 nite size and weight, a most beautiful theor}- 

 has been evolved which perfectly explains all 

 the observed chemical and ph3-sieal phenom- 

 ena ; but what chemist will venture to main- 

 tain the atomic theorj' as an actual and prova- 

 ble fact, in the face of the many difficulties 

 which such a conception of matter involves ? 



The nature of light and heat is another 



question which is even more difficult to answer 

 than the constitution of matter. Thej' are cer- 

 tainly immaterial, possessing neither weight 

 nor volume. The modern theoiy considers 

 them as a force, or mode of vibratory motion in 

 a hypothetical substance called ether. But the 

 existence of the ether has never been proved ; 

 and, in fact, if it does exist, it must possess 

 properties varying widelj' from any forms of 

 matter with which we are acquainted. All that 

 can be said is, that, granting its existence, the 

 phenomena of light and heat admit of a ready 

 explanation. 



Electricity is another substance concerning 

 the nature of which we know absolutely 

 nothing. To the question, What is electricity ? 

 there is but one answer, — We do not know. 

 We do know what it will do, and can make 

 it serve' us in an infinite variet3' of ways ; but 

 the most learned electrician is only in the same 

 position as that of a little child who can move 

 the lever which controls a great engine, but 

 knows nothing of its construction, or how the 

 the motion is produced. 



Chemical affinity oflTers a multitude of per- 

 plexing questions which as yet no one can 

 answer. Why does the oxygen of water leave 

 the hydrogen to which it is joined, to unite 

 with the sodium which is brought in contact 

 with it? Why are the proportions in which 

 the different elements unite among themselves, 

 fixed and invariable? Why does fluorine com- 

 bine so stronglj- with every known element but 

 one, while nitrogen, when forced into combi- 

 nation, confers an element of weakness upon 

 the entire compound ? No one has yet an- 

 swered these and innumerable similar ques- 

 tions. 



But the greatest mystery of all, and one 

 of which we know the least, is that of the 

 nature of life and mind. There is no appre- 

 ciable difference between a mass of dead and 

 living matter. It is onl}- in the possibilities 

 inherent in the two forms that we can recog- 

 nize the difference. An animal grows, and so 

 does a ciystal ; but no one would be likelj- to 

 mistake one process of growth for the other. 

 From the immense mammoth down to the 

 microscopic bacterium or plant-spore, all are 

 possessed of something we call life, which, as 

 long as it exists, possesses the power of repro- 

 ducing organisms similar to itself. We can, 

 apparently, destroy this mysterious principle, 

 but we cannot bring it back ; and it is not 

 probable that, in our present condition of ex- 

 istence, we shall ever know any thing more 

 regarding it. Some patient student of nature 

 may be able in future years to give us abso- 

 lute proof of what matter, light, electricity, 

 and chemical affinity really are ; but he who 



succeeds in imparting to the minutest quantity 

 of dead matter the wonderful vital force, will 

 have accomplished a greater and more won- 

 derful work than all who have preceded him, 

 and one which, as far as we can see at pres- 

 ent, is beyond the range of human possibility. 



[Original in Popular Science JVew*.] 

 ON THE STUDY OF NATURE. 



BY PROFESSOR N. S. SHALER. 



The degree to which the questioning of nature 

 may be associated with the occupation of a man 

 must manifestly vary in a great measure according 

 to. the nature of his vocation. Thus, in the case of 

 the physician, his life's work is properly bound up 

 with the task of continuously interrogating nature, 

 while with the lawyer it is at first hard to see 

 where his contact with the environing world is to 

 take place; the nature he finds in his occupation is 

 of the strictly human sort, and that by no means 

 in its best aspect. Nevertheless, the principles of 

 proof rest upon the most fundamental truths of the 

 universe; and the man of the law who is a philo- 

 sophical student of evidence, and who extends his 

 studies of that field over a wide realm, necessarily 

 becomes in the best sense a naturalist. .\Ithough 

 Greenleaf and Starkey had no intention of writing 

 a book for the naturalist, all students of nature 

 may find great profit from the study which they 

 have given to the principles of evidence. In truth, 

 we may say that in its best form the methods of 

 legal inquiry are profoundly naturalistic, though 

 they take in but a small part of the field of nature. 

 The education of the clergyman, if it be such as to 

 fit him for the great burden which comes with the 

 modern conditions of theology, mu-st lead towards 

 the sense of nature ; as one to whom is given the cure 

 of souls, &is first duty is to seek the resources which 

 mav lead to the reconciliation of the human spirit 

 with the universe in which it dwells. Whatever 

 else is to come to our modern theology, it is clear 

 to all that it must found at least a part of its 

 foundations in the world of visible fact. Above 

 all, men need to be reconciled to their conditions; 

 and in no other way can these be secured save by 

 showing them the moral dignity and beauty of the 

 nature about them. Every clergyman should feel in 

 some tangible way the conditions of this visible 

 world, and be prepared to aid those under his care 

 to gain the peace which that understanding may 

 give. 



The less learned employments commonly known 

 as trades afford in most cases a tolerable opportu- 

 nity for the training of the worker in the under- 

 standing of natural phenomena. The most com- 

 mon and the most generalized of these employments 

 is that of the farmer. Fortunately for the interests 

 of the better culture, more than one-half of the men 

 and women of the world must always be in contact 

 with the soil, — with that realm where nature is 

 most active, and where she teaches the most. There 

 are no essential changes of conditions necessary to 

 facilitate natural inquiry in this field of employ- 

 ment. Every farmer is perforce a naturalist. We 

 need only change the way in which he approaches 



