296 Some JReniarks on MM. Francis mid Croft's 



looking upon Gros's salts, the sulphate for example, as con- 

 taining the bichloramide of platina united with two equiva- 

 lents of sulphate of ammonia (Pt CL + Pt Ad,,) + 2(NH4. 

 O + S O3). As to the objection made by Gros to the exist- 

 ence of common sulphate of ammonia, that neither the acid 

 nor the base can be directly detected, it is well remarked by 

 Berzelius that the view taken by Gros does not in the slightest 

 degree render it easier of explanation. We find, however, 

 many analogous cases. Thus in the double oxalate of chrome 

 and potash, a very trifling quantity of the oxalic acid is shown 

 on the addition of a salt of lime. 



I consider that it is not calculated to advance science, when, 

 in order to avoid difficulties in the rational explanation of the 

 constitution and properties cf any substance, the theory of or- 

 ganic radicals is employed as unreservedly as it appears now 

 to be by many chemists. It gives an air of simplicity to re- 

 actions, very attractive at first sight, and very convenient for 

 explanation, but which, by making us satisfied by surface re- 

 semblance or plausibility, may retard important investigations. 

 If, in accordance with Gros's ideas, we make Pt CI N., Hy = X, 

 the question still remains, what is the structure of X? And 

 that question should never be lost sight of. But the substance 

 described by Reiset as the radical of Gros's salts*, and which 

 has indeed the formula of it (Pt CI N., H^), is not so consti- 

 tuted ; it is not at all of the series of the bichloride of platina, 

 to which Gros's salts belong, but to the protochloride, being 

 Pt CI + 2 NH3, whilst Magnus's salt is Pt CI + NH^. This is 

 evident from the way it is made. 



L. So7ne Remarks 07i Messrs. Francis and Croft's Abstracts 

 from the Foreign Jot/rnals. Brj A Cohrespondent. 



Sir, 



IT has lately been the fashion, especially among those who 

 have spent some time under the great teachers on the 

 continent, to declaim much against the backward state of che- 

 mistry in England, and to censure its cultivators in this country 

 for their tardy reception of the new doctrines and new facts 

 continually emanating Irom the fertile inventions and laborious 

 investigations of their continental brethren. 



Perhaps, to a certain extent, the charge may be well 

 founded, and thanks are due to Messrs. Francis and Croft 

 for their laudable endeavours to remove this opprobrium. 



On reading their abstracts from the foreign journals inserted 



* Francis and Croft's Abstracts, p. 284. 



