168 Aiiciii/sii of' Scieiiiijic Bucks. 



which is very nearly 1.5. Thus 6 parts become 9, and not II, 

 'as he loould have them to be. What becomes now of the ques- 

 tion, with which he concludes ? 



Muriate of ammonia, and the other muriates, are placed 

 Tivcion^ primary compounds, in utter disregard of his own distinc- 

 tions. By thus separating them from the other saline bodies, or 

 secondary compounds, to which they strictly belong, he destroys 

 all appearance of system. Nay, further, under the tide muriatic 

 acid, we have his prolix and not very edifying account of the 

 several processes for extracting subcarbnnate of soda from 

 sea salt. Here, we perceive nothing new in this edition, except 

 brief interpolations concerning the muriates of cadmium, and 

 of the vegeto-alkalies, the latter of which, ought by his own 

 notions, to have been placed among the salts of these bases. 

 Much perplexity, and teazing references to the first volume, are 

 occasioned by his jumbling together the chlorides and muriates. 

 In like manner, the title, iodic acid, is a misnomer ; the article 

 consists wholly of a misplaced detail of the iodates. Of the acid 

 itself he gives no account. The hydriodates and the iodides, 

 share the same confusion with the muriates. Under /?«oric acid, 

 we are told nothing of this substance itself, but we have an un- 

 satisfactory detail of its salts. These are vitiated thoroughly, 

 as to their proportions, by his extravagant error of '* consider- 

 ing the weight of an atom of fluorine to be 2 ;" whereas it is, by 

 simple arithmetic, in his own view of its nature, 2.25, and 

 the fluoric acid 2.375, from Berzelius's latest researches on 

 fluate of lime. This makes its atom, 0.125 x 19, when 

 regarded with Dr. Prout, as a multiple of hydrogen, by a whole 

 number. 



The formula which he gives, as from M. Gay-Lussac, for pre- 

 paring chlorocyanic acid, evidently furnishes a mixture of that 

 acid, and the muriatic. M. Thenard, who probably comprehends 

 the language and process of his distinguished colleague, gives 

 the following directions for preparing his chlorocyanic acid, in 

 the second edition of his Traite : " On pent le preparer, en 

 faisant passer un courant de chlore, dans une dissolution d'acide 

 hydrocyanique jusqu'a ce qu'elle decolore I'indigo dissous dans 

 Facide sulfurique, le privant de I'exc^s de chlore qu'elle contient, 

 par le mercure, et la soumettant ensuite a une chaleure moderee. 

 On obtient ainsi un fluide elastique, qui possede toutes les pro- 

 prietes attribues a Vacide prmsique oxigene. Cependant ce fluide 

 n'est point de I'acide chloro-cyanique pur ; car celui-ci ne pent 

 exister que liquide sous la pression de I'atmosphere, a la tempera- 

 ture de 15 a 20 degres ; c'est un melange d'acide carbonique 

 et d'acide chloro-cyanique dans des proportions variables qu'il 

 est difficile de determiner. L'acide chloro-cyanique ainsi obtenu 

 est incolore ; son odeur est si vive, qu'a une tres-petite dose, il 



