40 ■ THE POPULAR SCIENCE MONTHLY. 



laborious construction on the part of the manufacturer, operating 

 under chemical laws. Gradually there has arisen a new branch of 

 the science, whose aim is to produce artificially new compounds out 

 of old material ; and, since the living vegetable and animal offer 

 familiar though mysterious examples of the same process, it is only 

 natural that the philosopher should have tried to obtain, by known 

 methods, some of those results which are so silently and wonderfully 

 wrought out by the substance of living tissue. It will be the object 

 of this paper to indicate, in a non-technical way, some of the steps 

 which have been taken in the effort to compete with vitality. 



The word synthesis^ in its broad or general acceptance, signifies the 

 union of any two or more substances to form a physically-homoge- 

 neous mass, and into a product which cannot be mechanically divided 

 into dissimilar parts. Under this definition nearly every operation 

 of chemistry would be synthetical ; for, even in the case where an 

 element is isolated, this is done only at the expense of some other 

 bodies which pass into the condition of compounds ; thus, when gold 

 is precipitated in a metallic state from solution, we must use iron, 

 zinc, or some other substance, which shall become oxidized and dis- 

 solved in the place of the precipitated gold. 



Most cases of synthesis take place with great facility, automati- 

 cally in fact, for, when coal is burned, we start the fire, and after that 

 the oxygen and carbon unite to form carbonic acid, without any fur- 

 ther effort on our part. 



Now, in the world there are vast numbers of distinct compounds, 

 some of which have a simple and others a complex structure ; it is 

 found, by long experience, that there is a general disposition on the 

 part of these substances to pass from the state of feebly-united units 

 to that of great fixity ; thus, wood, which is composed of carbon, oxy- 

 gen, and hydrogen principally, burns in the air into two stable and 

 incombustible bodies, carbonic acid and water; and, in so doing, 

 evolves a large amount of heat. Neither of these final products, so 

 formed, can in any way be caused to evolve a further amount of en- 

 ergy, without bringing in the aid of external matter ; dynamically, 

 they are dead, as physiologically an animal is, when no longer capable 

 of movement. 



To raise a body into a state so that it contains within itself force 

 in a potential form, and so as to be able to liberate this force spon- 

 taneously, when certain conditions are fulfilled, is an operation opposed 

 to the general tendencies of the material world, and directly contrary 

 to what may be called the habits of non-vitalized matter. Now, it is 

 precisely this thing, this act of elevating some limited portion of mat- 

 ter to a higher plane, where its potentiality and complexity are both 

 increased, that is meant by chemical synthesis, and it will be seen how 

 much this use of the term restricts the meaning of the words as ordina- 

 rily used. 



