298 REYIKWS — CHEMICAL METHOD, NOTATION, &C. 



2°. If a part of the hydrogen of the organic substance exists in the state of water 

 (as in alcohol), it will be set free by the chlorine or oxygen, without substitution. 



The law is precise, and void of ambiguity : I do not purpose to inquire whether 

 or not it is correct {vide what I have raid concerning chlorine and oxygen substi- 

 tutions in this and the preceding chapter respectively). All that I have to say is, 

 that I have not adopted this law, and that I have myself formulated certain proposi- 

 tions which are altogether different, and arc applicable almost solely, to the hydro- 

 carbons. I then have nothing whatever to claim in the above law of substitutions- 

 It belongs entirely to Dumas. 



With regard to the second question, Dumas never concerned himself with it, un- 

 less indeed, after I had done so. It is this subject that I have for a long time had 

 in view in my researches (vide my opinion thereon in this chapter); it is in reference 

 to it, that I have advanced the following proposition : when there is equivalent 

 substitution of chlorine or bromine for hydrogen, the chlorine actually takes the place 

 thai was occupied by the hydrogen, and to a certain degree, fulfils the function* 

 thereof, consequently the chloro compound must be analogous with the compound from 

 which it was derived. 



Thus there is but little analog? between my opinion, my propositions — and the 

 law of Dumae. Here is the reply of this illustrious chemist to Berzelius, by whom 

 he had been rendered somewhat responsible for my extravagances. ' Berzelius 

 attributes to me, an opinion precisely contrary to that which I have always main- 

 tained, namely, that the chlorine in this case* takes the place of the hydrogen. I 

 have never said anything of the kind, neither can anything of the kind be deduced 

 from the opinions I have put forward with regard to this order of facts. To repre- 

 sent me as saying that hydrogen is replaced by chlorine, which fulfils the same 

 functions, is to attribute to me an opinion against which I protest most strongly, a3 

 it is opposed to all that I have written upon these matters. The law of substitutions 

 is an empiric law and nothing more ; it expresses a relation between the hydrogen 

 expelled, and the chlorine retained. I am not responsible for the gross exaggera- 

 tion with which Laurent has invested my theory ; his analyses moreover do not 

 merit any confidence.' 



Dumas and I made use of the same word substitution, from which circumstance 

 arose much of the confusion that prevails on this subject. This confusion was still 

 further augmented, by our employment of special terminations in ase, ese, and tie, 

 &c, terminations conceived by Dumas a3 expressive of the relation between the 

 number of hydrogen atoms liberated, and the number of other atoms retained, but 

 employed by me to indicate that the chloro-conipound in the case of an equivalent 

 tubsiitution, must still preserve the constitution of the original substance. 



Thus Dumus represented the constitution of essence of canella by this formula : 

 C 18 H l4 2 + H 2 ; that of chloride ofcinnamylby this: C 18 H 14 2 + C1 2 ; and the 

 composition of chlorocinnose ( = the hydride — 4H 2 +4rCl 2 ) by C 18 H 8 C1 8 0*, observ- 

 ing that he called the body chlorocinnose provisonally, inasmuch as he did not know 

 how to represent its molecular constitution, nor with what body to compare it. 



My opinion was very different. If I had considered essence of canella as forming 

 a unique molecule C 18 H I6 0' : , and had named it cinnamyl, I should have called the 



' " I had just made the chlorhydate of chloretherise, and an acetate of chlororaethylene. I 

 maintained that the first body had the same constitution as Dutch liquid, and that in tho 

 second, the atoms were disposed exactly as in the acetate of methylene. It was in reference 

 to this opinion, that Berzelius chose to lender Dumas responsible for my errors." 



