Chemical Science, 207 



the oil obtained by the distillation of the nutme|^, all produce this 

 efTect when their quantity is not more than one-fiftieth part of the 

 luminous oily solution of phosphorus. The same effect is pro- 

 duced by adding about a fifYh of the oils of anniseed, cajeput, 

 lavender, rue, sassafras, fern, cascarilla, mint, orange flowers, fen- 

 nel, valerian, cherry laurel, or bitter almonds, or balsam of copaiba; 

 but the oil of cinnamon, rectified petroleum, balsam of Peru, and 

 caiQphor» have np such effect. — Anrud, der Phys, 1826, p. 125. 



16. On the Injlammation of Powder when struck by Brass, 8fc, 

 — Iron has been excluded from powder-works as subject to cause 

 sparks by a blow, and brass and copper have been recommended 

 in its place. M. le Col. Aubert has remarked, that brass on brass 

 can inflame powder, and has made experiments on the subject 

 before a committee, the result of which is as follows : — Inflamma- 

 tion of the powder takes place when the blow is given by iron 

 against iron ; iron against brass ; brass against brass ; iron against 

 marble ; lead against lead, or against wood, when the blow is pro- 

 duced by a leaden ball shot from a fire-arm. As yet the powder 

 has not been inflamed by the blow of an iron hammer against lead 

 or wood. — Bull, de la Sac. d' Encouragement; Bull, Univ, 



17. Cementation of Iron by Cast Iron. — Pure iron, when sur«? 

 rounded by, and in contact with, cast iron turnings, and heated, 

 is carbonised very rapidly, so as to harden, to temper, and, in fact, 

 to exhibit all the properties of steel. M. Gautier finds this a very 

 advantageous process in numerous cases, especially where the arti- 

 cles to be case-hardened, or converted into steel, are small, as iron 

 wire, or wire gauze. The temperature required is not so high as 

 that necessary in the ordinary process of cementation, and the 

 pieces to be carbonised are not injured in form. The kind of cast 

 iron used should be the gray metal, and the more minutely it is 

 divided the more rapid and complete is the operation. By cover- 

 ing the mass of cast metal, in which the iron to be carbonised is 

 enveloped, with sand, oxidation, from contact of the air, is prevented, 

 and the cast metal may be used many times. Plumbago experi- 

 mented with in the same manner does not produce the effect. — 

 Jour, de Pharmade, 1827, p. 18. 



18. On the Preparation of Ferro-prussiate of Potash, by M, 

 Gautier. — Numerous investigations induced M. Gautier to conclude, 

 that, i. When animal matter is calcined alone it yields but little 

 cyanogen, ii. That when mixed with potash it gives more, but the 

 cyanuret is not ferruretted. iii. That ammonia is then produced in 

 large quantity, iv. That the substitution of nitre for potash, and 

 the addition of iron or scales of iron, augmented the production 

 of cyanogen, and gave a ferro-prussiate. The following is the 

 process of manufacture to which M. Gautier has ultimately arrived, 



