232 Scientific Intelligence. [Sept. 



II. New application of the Steam Engine. 



Some time ago a steam-engine was mounted upon wheels at 

 "Leeds, and made to move along a rail road by means of a rack 

 wheel, dragging after it a number of waggons loaded with coals. 

 The experiment succteded so well at Leeds, that a similar engine 

 has been erected at Newcastle, about a mile north from that town. 

 It moves at the rate of three miles an hour, dragging after it 14 

 watrcons, loaJeii each with about two tuns of coals ; so that in this 

 case the expense of 14 horses is saved by the substitution of this steam- 

 engine. 1 have no doubt that this new employment of the steam- 

 engine will soon becom<- general in coal countries. 1 was told of 

 another steam-engine at Newcastle, employed for a similar pur- 

 pose, and moving along, without any rack wheel, simply by its 

 friction against the nil road ; but 1 had no opportunity of seeing 

 this machine, or of judgiig of its execution. One would be dis- 

 posed, however, to give the preference to the engine moved by 

 weans of a rack wheel. 



III. Composition of the Vegetable Acids. 



Berzelius has just published the result of his new experiments to 

 determine the composition of the vegetable acids. (Sehweigger's 

 Journal fur Chemie und Physik, x. 2, p. 246.) 1 shall lay the 

 numbers which he obtained before the readers: — 



f Oxygen 66*211 . . or . . 6 atoms 



Oxalic Acid } Carbon 3.S-021 1 



^Hydrojren 0-/.'8 1 



f Oxygen 59-882 5 



Tartaric Acid . . . . \ Carbon 36-167 4 



£ Hydrogen.... 3-751 5 



f Oxygen 60-81S 8 



Saclaclic yield ....) Carbon 34-164 6 



£ Hydrogen 5-018 10 



f Oxygen 46'734 3 



Acetic Acid ) Carbon 46-871 4 



(Hydrogen 6-195 6 



f Oxygen 48-08 3 



Succinic Acid < Carbon 47 -40 4 



^Hydrogen . . .. 4-52 4 



fOxveren . 55-072 :i 



Citric Aid ] Carbon .41-290 3 



£ Hydrogen 3-634 3 



f Oxygen 20-00 3 



Bcnzoir Aad \ Carbon 74*74 15 



/Hydrogen 5-26 12 



These determinations seem liable to some objections j but as the 



