August 30, 1889.] 



SCIENCE 



143 



n I" I 



i |H|ti'l' Hi' I 



PCETSCH FREEZING PROCESS; IN SHAFT SINKING, AS APPLIED 

 AT THE CHAPIN MINE. 



ing was obtained for the timbers, and the timbering was com- 

 pleted from the surface of the ground to the excavated depth. 



The obvious remedy for inflow from the rock will be in the 

 future to put the pipes far enough into the ledge to freeze off the 

 surface seams. Pipes are now being put down for a coal mining 

 shaft at Wyoming, Pa., and they will be put several feet into the 

 rock, which will no doubt intercept all troublesome percolation. 



This operation of this process was the first application on 

 any considerable scale in the United States. Water is the engineer's 

 most troublesome enemy, and its conversion into a barrier of de- 

 fence is a triumph of engineering as effective as it is novel. This 

 process can be applied to excavations for bridge piers, to tunnels, 

 and to other general work of a difficult and expensive character as 

 well as to shafts. But in shaff work alone it should be invaluable, 

 as by it numerous valuable deposits of coal and other minerals, 

 now inaccessible on account of overlying strata of water-bearing 

 materials, can be reached, as in the case of the Chapin mines, and 

 m those Belgian coal mines which first led Mr. Poetsch to devise 

 his process. 



THE PRODUCTION OF SUGAR. 



Yesterday the formation of sugar by plants, says Ward Cold- 

 ridge, in K7iowledge, was one of the mysteries of nature. Chemists 

 and botanists, while they knew that ordinary chemical attractions 

 must be the cause, were yet completely in the dark as to how these 

 forces worked. They realized that plants started with carbonic 

 and and water, and from these waste products of animal existence 

 built up in some unknown way the complex compound, sugar. 

 From the deadly choke-damp to the luxury sugar was a great trans- 

 formation. The plants could thus build, but men of science could 

 not comprehend the process. 



To-day, as the result of some brilliant researches, the explanation 

 has been found. A simple compound, the formation of which by 

 the plant can be readily accounted for, has been transformed into 

 a sugar. To understand the process, it must be realized that 

 abundant evidence proves that plants promote processes which are 

 the opposites of combustion or oxidation. Plants liberate oxygen 

 from its compounds, and absorb that with which it was previously 

 combined. They can liberate oxygen from so stable a compound 

 as carbonic acid, and in water find a source for the hydrogen which 

 IS essential to their development. The products which could thus 

 be formed are, respectively, from carbonic acid, the lower oxide of 

 carbon and oxygen ; from water, the gases hydrogen and oxygen. 

 Experiments have shown that under the influence of the silent elec- 

 tric discharge, and even without it, carbon monoxide and hydrogen 

 combine to form a simple compound, formic aldehyde, which is 

 immediately connected with the formic acid of the ant and of the 

 stinging-nettle. So the changes which occur in the plant under 

 the combined influence of sunlight and chlorophyl may be repre- 

 sented in symbols as follows : — 



COo = CO 4- O ; H,0 = Ha-t-O 



Carbonic Carbonic 4- Oxygen ; Water = Hydrogen -f Oxygen. 



acid. oxide. 



CO-hHs = CHoO 



Formic aldehyde. 

 This formic aldehyde was the substance experimented on. When 

 it was suitably treated in the presence of the hydrate of lime, Ca 

 (HO)2, it was induced to combine with itself and to form another 

 compound. The latter is composed of the same ultimate indivisible 

 particles (atoms) and in the same proportions ; but they are now 

 differently arranged side by side, and with a larger number in the 

 unit aggregation which chemists call molecules. This compound 

 has now been finally proved to contain not one, but at least two or 

 three members of the family of substances, carbohydrates, to which 

 sugar belongs. Thus in our laboratories can now be imitated the 

 process of which plants previously held the secret. 



While, however, the fact is marvellous that a sugar has been 

 obtained artificially, it must be remembered that the process is 

 absolutely uneconomical, for the yield is very small. This remark, 

 too, applies to another process of artificial production. The sweet 

 Mscid liquid, glycerin, and its stinking, irritating offspring, acrolein, 

 which gives the nasty smell of burning fat, have both been trans- 

 formed into sugar ; but the quantity obtained is very small in pro- 



