26 Anmversary Address by Sir William Huggins. [Nov. 30, 
Dr. Perkin also extended the same methods to the synthetical formation 
of carbon rings of the aromatic series, obtaining by means of ingeniously 
designed reactions derivatives of hydrindonaphthene and tetrahydronaphtha- 
lene. 
But whilst the above achievements depend mainly on happily conceived 
and brilliantly executed extensions of the malonic and aceto-acetic ester 
syntheses, Perkin has, by a remarkable development of the Frankland and 
Duppa reaction for the synthesis of hydroxyacids, been successful in building 
up the important camphoronic acid in such a manner as to place its 
constitution beyond doubt (1897). 
Dr. Perkin has further devoted much attention to the important subject 
of the constitution of camphor, towards the elucidation of which he has 
contributed valuable experimental evidence embodied in a most important 
and elaborate paper, containing the results of many years’ work in conjunction 
with numerous pupils, entitled “Sulphocamphylic acid and Isolauronolic 
acid, with remarks on the Constitution of Camphor and some of its derivates ” 
(1898). Bearing on the same subject are later communications on camphoric 
acid and isocamphoronic acid. 
About the year 1900, Perkin, in prosecuting his researches on the 
constitution of camphor compounds, succeeded in devising synthetical 
methods for the production of what he has termed “bridged rings,” of which 
a simple example is furnished by the hydrocarbon dicyclopentane 
CH — CH, 
ee 2 
NCH cm 
The universal admiration of organic chemists has been called forth by 
these investigations; they reveal, indeed, a wonderful capacity for devising 
reactions which coerce carbon atoms to fall into the desired groupings. 
Of other publications displaying not only extraordinary experimental skill 
but close reasoning and the power of interpreting results, mention may be 
made of Dr. Perkin’s memorable researches on the constitution of dehydra- 
cetic acid, berberine, brasilin, and hematoxylin respectively. 
During the present year (1904), Dr. Perkin has made perhaps the most 
remarkable addition to the long list of his achievements by successfully 
synthesising terpin, inactive terpineol, and dipentene, substances which had 
previously engaged the attention of some of the greatest masters of organic 
chemistry. 7 
