French Method

The choice of the radiant panel only depends upon the rate of development of the international test procedure. If this is not available in sufficient time, the French method will be taken. 

The methods of making puff pastry can be divided into the Scotch method and the English or French method. 

The English (also known as the French) Method. In contrast, in the English method the fat is rolled out between the layers of pastry. Not too surprisingly the Scotch method is less likely to give a discrete layer of fat between the layers. 

Bullet Impact Test (pp B332 B335 to B338) Bullet Test, French Method (pp 333 B 339) No sensitivity tests are described in Vol III of Encycl, while in Vol IV, the tests are described under DETONATION (AND EXPLOSION), EXPERIMENTAL PROCEDURES and under DETONATION (AND EXPLOSION) BY INFLUENCE... 

Probe oder Bleiblocleansbachung Methode in Ger). The French method of conducting the test is slightly different and is described as Coefficient d utillisation pratique (abbr CUP) ou Epreuve de travail sp6cifique in Vol 1, pp IX X and in Vol 3, p C3 0.- Official test of the French Army is given as " Travail specifique relatif, test 13 , under Essais d Explosifs... 

Epreuve la bombe ou Essai de poudre on vase clos. (Test in the Bomb or Test of Propellant in a Closed Vessel) (Similar methods are called in English, f Closed Bomb Tests , and they are described in Vol 3, pp C330 to C345 of Encycl. The French method is described in detail in the book of instructions issued in about 1950 by "La Commission des Substances Explosives , 4eme partie, articles 189—210, which could be obtd on request from the Services des Poudres, thru the Etat-Major de l Armee, 2eme Bureau, Paris, France... 

The introduction into this oountry of the manufacture. of cylindrical glass by the French method, was due to the Messrs. Change of Wost Bromwich, near Birmingham, and Mr. Hartley, now of Sunderland, hut then VOL. II. 

Blasting Gelatin See table under item D(French Method) ... 

Table IV Rifle Bullet Impact Test by the French Method...

Table IV. Rifle Bullet Impact Test by French Method B 339...

Acid usage control. The French method is based on the use of the spent acid from trinitration for dinitration after it has been fortified, and on further utilization of the spent acid from dinitration in the mononitration stage. The composition of the mixtures is calculated as described above. 

The spent acid obtained from mononitration by the method described should contain traces of nitric acid (0.2-0.4% of HN03). Its absence may be an indication that the amount of nitric acid used for the nitration was insufficient and consequently that part of the toluene has remained unnitrated. In such cases the portion of acid used for the next batches should be richer in HN03, since in the old French method the unreacted toluene is not distilled off from the mononitrotoluenes. 

There are various methods of purification of the TNT with sodium sulphite. French method... 

In the French method the ground TNT is mixed with a 7.5% solution of Na2S03 at room temperature for 2 hr. The operation is carried out in wooden vats, 1.3 m high and 1.3 m in diameter (Fig. 78), using 750 kg of TNT and 750 1. of the solution at a time. Then the mixture in the vat is drained off to a vacuum filter, where the TNT is filtered off, washed with water four times, and sent to a drier. 

The nitration of naphthalene to dinitronaphthalene (after Pascal [20a]) is effected in a nitrator essentially of die sane type as that used for the nitration of naphthalene to nitronaphthalene by the French method (Fig. 108, p. 441), the only difference being in the outlet which is wider at the bottom - 8 cm in diameter - since the nitration product is solid. 

In Russia, as Lebedev reported, the French method gave satisfactory results in summer time only, whereas for the most part of the yeM (autumn, winter) on account of high heat losses, nitration was never complete Mid the picric acid yield was low (150-160 parts per 100 parts of phenol). Moreover, the product contained high proportions of mono- and di-nitrophenols. 

Impact Sensitivity. FI(figure of insensitive-ness) 111% PA(Ref 6) impact work for 50% ezpln with 2kg wt is 10.4 kg m/cm (Ref 11) impact sensitivity by the French method with 10kg wt for 50% point 36cm vs 17cm for PA (Ref 16). BlattCRef 22)gives FI = 122% PA... 

In the French method the reaction between methanol and phosgene takes place in large vessels fitted with agitators and cooled externally. The hydrochloric acid which forms is rapidly... 

French Method. Because of the limited availability of bromine the manufacture of bromoacetone was carried out in France during the war by treating acetone with sodium bromate and sodium chlorate in presence of sulphuric acid instead of by the direct action of bromine on acetone. The following reaction takes place ... 

For detailed descriptions of the French method (Pascal), see Giua, Chimica degli aggressivi chimici, Turin, 1931. 68 ff. 

Manufacture, French method Metallic zinc is heated in a crucible... 

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