162 Intelligence and Miscellaneous Articles, 



tion of my trangressions in this direction, the offence is imputed to 

 me of enumerating seven oxides of sulphur, and six of carbon. On 

 these points I decline to enter upon any defence, further than to say 

 that, in the best works on chemistry recently published, precisely the 

 same enumeration of these compounds has been made. If I have 

 sinned against scientific accuracy, of which I must say I am quite 

 unconscious, precisely the same offence has been committed by 

 modern chemists of great eminence, such as Pelouze and Fremy, 

 Regnault, Miller, and several others ; and I am at a loss to under- 

 stand why so humble an individual as myself should be singled out 

 for especial censure, while my distinguished contemporaries are per- 

 mitted to pass unscathed. Many of the atomic groups here referred 

 to have certainly not as yet been insulated, and are therefore to a 

 certain extent hypothetic ; but this does not appear to me to consti- 

 tute any sufficient reason why their constitution and properties, as 

 far as these can be deduced from the known compounds in which they 

 occur, should not be considered and discussed. 



Of a somewhat similar character are the remarks upon my mode 

 of dealing with the compounds of carbon and hydrogen. In page 

 502 I state that these numerous bodies form properly a part of 

 organic chemistry, but that there are a few of them, in particular 

 C 4 H 4 and C 2 H 4 , to which the student should pay an early attention. 

 Notwithstanding this distinct announcement of the plan which I in- 

 tended to pursue, and the fact that in all almost all treatises on 

 chemistry defiant gas and marsh-gas alone are discussed in con- 

 nexion with carbon, the reviewer does not hesitate to use the follow- 

 ing language : — " From these instances it will be seen that Dr. 

 Apjohn's lists of known compounds include many substances with 

 which other chemists are by no means well acquainted : hence it is 

 natural he should require to make room for them by ignoring sub- 

 stances which often receive a considerable share of attention. Thus 

 (page 502) the usual list of hydrocarbons is much curtailed." Of 

 the tone of this extract, and there are several other passages in the 

 review on a level with it, I do not complain. Some persons think 

 that in every kind of controversy a sarcasm or a sneer constitutes 

 the most effective weapon, and therefore naturally resort to them. 

 I would suggest, however, that there is no sufficient excuse for the 

 misstatement or distortion of facts exemplified in the passage which 

 1 have just quoted. 



In the remainder of the review there is a good deal of criticism of 

 a hostile nature, upon the details of which it is not my intention to 

 enter. I am quite prepared to admit that in my book there are some 

 omissions, and that in particular the interesting compounds of silicon 

 with hydrogen and with oxygen, discovered by Wohler and Buff, 

 have not been noticed. This was not an intentional omission ; for 

 the manuscript was prepared, but, through some accident, not for- 

 warded to the printer. There are also other errors which I have no 

 disposition to deny or justify. It is, for example, quite true that 

 the rival claims of Watt and Cavendish had reference, not to the 

 discovery of hydrogen, but to a kindred question — the discovery of 

 the composition of water ; and that the combustion of the diamond 



