On definite Proportions. 197 



upon the fore-ends of the shafts, he is con fined between 

 them by the weight, and prevented from rising. Mr. 

 Martin's method of relieving a horse in snch a situation is 

 thus efFcclcd. The locking bar E is first removed from 

 the staples ce of the shafts, with which the body of this, 

 like most other carts, is provided, for the purpose of turning 

 up and discharging its contents : this being done, a man 

 must creep under the cart from behind, and fiist put down 

 the iei.s or .-lays DD, which were before turned up out of 

 the way beneath the cart ; then unscrewing the nuts BB, 

 the shafts fall down, completely detached from the body of 

 the cart, as represented in the figures ; and nothing then 

 prevents the horse from getting up, the cart remainitig 

 supported in front by the legs DD. C is an additional leg 

 foicle'.t up beneath the cart ; it is of such a length that it will, 

 when set upright, support the cart in an horizontal posi- 

 tion, and is used to support the cart when lihed up whilst 

 the shahs are fixed on again : the legs DD are provided 

 with iron hooks, one of which is seen at F, which retain 

 them steadily in their places, when the weight of the cart 

 tends to throw them forwards: the leg C is provided with 

 a similar hook. 



XXXT. An Attempt to determine the dejinite and simple Pro- 

 portions, in which the constitnent Parts ofunnrganic Sui- 

 stances are united ivith each other. Bi/ Jacob Berzr- 

 Lius, Professor of Medicine and Pharmacij, and M.R.J. 

 Stochliolm. 



[Continued from page 'JO ] 



IV. CoppKR AND Sulphur. 



1.) J. EN grammes of the pure copper, callod copper 

 ashes, or dust, were well mixed with ten grammes of pure 

 sulphur, and strongly ignited in a glass retort, furnished 

 with a receiver and a tube of safety ; they acquired an ad- 

 dition of 2-56 grammes. This copper dust is an extremely 

 line powder obtained in the sinelfing-houses when the 

 metal is refined. [It consists of minute grains, which are 

 throvxn up to a height of six or eight inches, wliile the 

 copper is cooling, after the removal of the ashes and cin- 

 ders froiTi the furnace, a'lil which generally fall down again 

 in the foriTi of a fine mttallic shower, except when they 

 are intercepted by a shovel, which is moved backwards and 

 forwards tor the purpose. — Gilbert.] 



N li 5.) lu 



