150 



CHEMISTRY. (NOMENCLATURE.) 



of micro-organisms within it. Prof. Burdon- 

 Sanderson spoke of the difficulty, and often 

 impossibility, of distinguishing between differ- 

 ent organisms as constituting the main diffi- 

 culty in studying them. Prof. Kay Lankester 

 remarked that it was curious that the nitrify- 

 ing organism had never yet been isolated; its 

 presence had only been inferred, and it had 

 never been satisfactorily separated and iden- 

 tified. Dr. Brunton said that it was highly 

 probable that the symptoms occurring in cer- 

 tain diseases were due to poisons formed by 

 the action of organisms, and not directly to 

 the organisms themselves. This was probably 

 the case in cholera. Micro-organisms may 

 even produce substances fatal to themselves 

 e. g., phenyl compounds. This is also the case 

 with higher organisms, the retention of urine 

 in man being often attended with fatal results. 

 Pepsin converted albuminoids into peptones, 

 but it was important to note that Brieger had 

 observed that an alkaloid, having an action 

 similar to curare, was formed during peptic 

 digestion, and an alkaloid having a similar 

 action had been obtained from human urine. 

 These facts rendered it probable that alkaloids 

 might be formed in the intestinal canal and 

 absorbed into the general circulation. 



Nomenclature. The Committee on Chemical 

 Nomenclature of the British Association rec- 

 ommend the retention of the terminations ous 

 and ic and ate and ite and the prefixes hypo 

 and hyper, as they are ordinarily used, as being 

 fixed terras, with well-understood meanings 

 not liable to be misunderstood. In case a 

 metal whose two salifiable oxides are repre- 

 sented by names terminating in ous and ic 

 forms also an acid-forming oxide, the distinc- 

 tion is made sufficiently clear by designating 

 the last as an anhydride (or acid). Indifferent 

 oxides may be classified and named by regard- 

 ing them as compounds of salifiable with acid- 

 forming oxides, as when Cr 2 O 4 is called chro- 

 mic chromate. Of the prefixes hypo and sub, 

 custom applies the former to acids and acid- 

 forming oxides, and the latter to salifiable and 

 indifferent oxides. The termination ous should 

 be written ious or eous as seldom as possible. 

 In the names of salts of which only one class 

 is known, it is not a matter of much difference 

 whether we say, for instance, magnesium sul- 

 phate or magnesic sulphate except in the case 

 of carbon compounds, when neglect to affix ic 

 to the names of the positive radicals in ethereal 

 salts may lead to confusion in the spoken name. 

 Thus the ear can not distinguish between ethyl 

 phenylacetate and ethylphenyl acetate; but 

 all ambiguity is removed by saying ethylic phe- 

 nylacetate and ethyl phenylicacetate. In com- 

 plex cases where the modes of naming by ous 

 and ic terminations, etc., prove inadequate, re- 

 sort may be had to numeral designations, which 

 appear especially admissible in cases where an 

 oxide occurs which is intermediate between 

 the ous and the ic stage, and at the same time 

 can not be classed as a compound of oxides 



already classified and named ; but, in applying 

 numerical designations, it is important to select 

 only such as are free from hypothesis and af- 

 ford correct information. In this respect chem- 

 ists appear not to have been sufficiently care- 

 ful of late years. In employing numerical 

 designations to indicate molecular composition 

 in cases where this is established, it is impor- 

 tant to express the number of atoms of each 

 constituent element, as dicarbon hexachloride, 

 CaCle. But in the case of solid and liquid 

 bodies of which the molecular weight is un- 

 known, or which may vary with temperature, 

 the name should merely indicate the relative 

 proportions in which the constituents are asso- 

 ciated; or, more explicitly, the name should 

 indicate the proportion of the radical associ- 

 ated with what may be termed the character- 

 istic element of the compound. No difficulty 

 occurs in the case of the chlorides or analogous 

 compounds of the monad elements generally, 

 which may be termed mono-, di-, tri-, tetra-, pen- 

 ta-, or hexa-chloride, etc., according as combi- 

 nation is in the proportion of 1, 2, 3, 4, 5, or 6 

 atoms of chlorine to one atom of the charac- 

 teristic element. The application of this sys- 

 tem would involve the use of the names tin di- 

 chloride and iron trichloride (not sesqnichlo- 

 ride) for stannous and ferric chlorides respect- 

 ively, names which accurately express the 

 relative proportions of metal and of chlorine in 

 those compounds, without any hypothesis as to 

 their molecular composition. It will, however, 

 involve a slight departure from the existing 

 practice when applied to oxides, sulphides, and 

 other compounds of polyad elements ; thus ox- 

 ides of the type (R 9 )"O would be termed hemi- 

 oxides, since they consist of the characteristic 

 element and oxygen in the proportion of one 

 atom of the former to half an atom of the lat- 

 ter. Oxides of the type (R a ) Tl 8 would be 

 termed sesqui-oxides, since the characteristic 

 element and oxygen are present in the propor- 

 tion of one of the former to one and a half of 

 the latter; oxides of the type R a 6 would be 

 termed sesterti-oxides as they contain oxygen 

 and the characteristic element in the propor- 

 tion of two and one half atoms to one of the 

 latter ; oxides of the types RO, RO 3 , R0 a , and 

 RO 4 , would be termed respectively mono-, di-, 

 tri-, and tetfr-oxides. 



The subject of nomenclature was also con- 

 sidered, particularly with reference to organic 

 compounds, in a paper by Prof. Odling. The 

 author held that, notwithstanding many rec- 

 ognized advantages, structural names are un- 

 suitable for general use, more especially as ap- 

 plied to fundamental hydrocarbons, alcohols, 

 and acids by reason of their length, complexi- 

 ty, and want of ready indicativeness ; by the cir- 

 cumstance of their being based on conceptions 

 of chemical constitution of a kind pointed out 

 by experience as eminently liable to change ; 

 and by the further circumstance of their repre- 

 senting a one-sided and, so far, an untruthful 

 notion of the bodies designated.' Structural 





