596 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



had a pure and intense green and retained its fluidity for several months. 

 After exposure for several days to intense cold, however, the bottle was 

 observed to be full of a solid body consisting of minute crystals of ordinary 

 violet chrome alum. The conversion of the violet into the green varieties 

 is well known, but the reverse by means of cold is something new. 



Vegetable Flannel. 



This article is manufactured in Germany from the Pinus Silvestris. It is 

 said a large number of persons are now engaged in the Black Forests in 

 the various processes of separating the oil and the fiber, called Waldwold, 

 or forest wool, from the pine leaves, and of spinning, weaving and knitting 

 the yarn. This vegetable flannel is believed to have the important power 

 of re-establishing the functions of the skin when they have been interfered 

 with by accidental causes. 



Comparative Value of Coals. 



It is found that a pound of the best "Welsh anthracite coal is capable of 

 converting from 9| to 10 lbs. of water of a given temperature into steam; 

 whereas the same amount of the best Newcastle bituminous coal will con- 

 vert only 8| lbs. of water at the same temperature into steam. The infe- 

 rior Newcastle will not raise more than 6| lbs. of water into steam. 



Transformation of Protoxide of Nitrogen into Ammonia and 



Nitric Acid. 

 M. Peroz, in a memoir to tlie French Academy of Sciences, states that he 

 passed nitrous oxide into a cooled tabulated receiver to arrest most of the 

 water, then through a curved tube filled with hydrate of potash and lumps 

 of lime. On heating the tube to a dull redness and as soon as the current 

 of moist protoxide is well established, ammonia is abundantly disengaged, 

 .'ind after some time nitric acid may be found in the saline mass in the tube. 



The Armstrong and Whitworth Guns. 



A test was lately made in England of the 12-pounder gun made by Arm- 

 strong and by Whitworth. The charges used consisted of one and a half 

 pounds to three pounds of powder, and a number of shots varying from 

 three to six pounds. The mode of testing was most severe, an air-space 

 being left between the shot and the cartridge. The breech-loading Arm- 

 strong became unserviceable at the forty-second round; the muzzle-loading 

 short Armstrong at the sixtieth round. In both instances they simply 

 cracked without a separation of parts. The Whitworth gun burst intu 

 eleven pieces at the ninetieth round. The tests applied to each gun were 

 similar in all respects. 



A Loom for One of the Nobility. 



Messrs. Stewart, of Kilmarnock, Scotland, have constructed an elegant 

 loom, of yellow polished pine, with all the necessary properties for the 

 Countess of Eglington, who intends to manufacture her own dresses. 



