SEPTEMBER 25, 1913]| 
NATURE 
103 
and also the great prevalence of lithium in very 
small quantities. He pointed out that the latter 
fact is of considerable interest with reference to 
recent work on radioactivity. 
Again, Hartley was the first to discover the 
relation between the wave-lengths of lines in the 
spectra of analogous elements. He explained the 
fact by saying that analogous elements do not 
consist of different kinds of matter, but of different 
quantities of the same kind of matter. This 
relation possesses a fundamental significance in 
connection with modern views on the electronic 
nature of the atom; and, moreover, the deduction 
Hartley himself made affords support to the 
theories recently put forward as to the evolution 
of the elements. 
In his work on flame spectra, Hartley showed 
the value of the oxy-hydrogen flame. In con- 
junction with Dr. H. Ramage, he discovered the 
existence of the bands in the flame spectra of many 
metals, and from a study of these he was able 
to draw important conclusions about the relation 
between the band and line spectra of the same 
element. Further, both alone and with Ramage, 
he made an exhaustive study of the spectroscopy 
of the Bessemer process, and was able to con- 
tribute largely to the knowledge of the thermo- 
chemistry of that process. 
With Hartley’s work on absorption spectra it 
is not possible adequately to deal in a_ brief 
epitome. In this direction he has undoubtedly 
founded a field of research which is of great 
importance and promise, as Prof. von Baeyer has 
recognised. Hartley was the first to establish a 
scientific method of observation and recording of 
absorption spectra, and was the first to show that 
they may be applied to the problems of chemical 
constitution. In a series of nearly fifty papers 
he dealt with the absorption exerted by both 
inorganic and organic compounds. In the first- 
named, he showed how the spectroscopic evidence 
was antagonistic to the ionic hypothesis in its 
earlier development. In the second, he showed, 
among many other fundamentally important facts, 
that the colour of all dyestuffs and similar com- 
pounds is to be traced to the absorptive power 
of the hydrocarbons from which they are derived. 
In fact, he gave the scientific explanation of the 
chromophore theory. Also may be mentioned his 
investigation of the absorption exerted by the 
alkaloids, and his record of facts that are of great 
importance to the synthetic chemist, and also 
from the medico-legal point of view. The applica- 
tion of the method to the elucidation of the con- 
stitution of carbostyril, o-oxycarbanil, isatin, and 
other compounds is perhaps too well known to 
need emphasis. It is impossible to specify the 
many lines of work Hartley successfully carried 
on in absorption spectra. He has left accurate 
records of the absorption curves of a vast number 
of substances, and he discovered a series of funda- 
mental laws governing the relation between 
absorption and chemical constitution with which 
his name always will be associated. 
NO. 2291, VOL. 92] 
In conclusion, it may well be said of Hartley 
that whatever research he undertook, his results 
were always most valuable, and he conferred 
distinction upon everything to which he put his 
hand. EB. Cl CBs 
DR. ALEXANDER MACFARLANE. 
R. ALEXANDER MACFARLANE, whose 
name is well known to workers in vector 
algebras, died at his home in Chatham, Ontario, 
on August 28. He was born in Blairgowrie on 
April 21, 1851, and was trained as a pupil teacher. 
As-a student in Edinburgh University he soon 
impressed his contemporaries with his mental 
capacity. He gained high distinctions in the class 
of logic and philosophy as well as in mathematics 
and natural philosophy. After graduating with 
first class mathematical honours, he proceeded to 
study for the science degree, gaining his doctorate 
in 1878 with a thesis on the conditions governing 
the sparking of electricity between electrodes in 
air and in paraffin. The experimental work was 
carried out in Prof. Tait’s laboratory, but the idea 
of the research was entirely Dr. Macfarlane’s own. 
Some of these early results are referred to by Clerk 
Maxwell in his “Electricity and Magnetism.” 
Dr. Macfarlane did not, however, pursue experi- 
mental research, but turned his mind to the 
application of mathematical symbols in somewhat 
unusual directions. His “Algebra of Logic” was 
published in the late seventies, and he read 
before the Royal Society of Edinburgh a series 
of papers on the algebra of the relationships of 
consanguinity and affinity. In 1885 he was 
appointed professor of physics in Texas Univer- 
sity, and was of great service in developing that 
institution as a centre of scientific teaching. About 
this time he published a book on physical arith- 
metic, which was the first sustained systematic 
treatment of methods of calculation useful in 
physical reductions. He was also the compiler of 
a compact and well-arranged book of mathe- 
matical tables. 
He retired from active teaching in 1894, and 
some years later settled in Canada on a large 
farm which had been bequeathed to him by an 
uncle. Here and subsequently in the neighbour- 
ing town of Chatham, he turned his attention to 
the study of vector algebras. Already he had 
taken part in the controversy which appeared in 
Nature (1893-4) as to the rival merits of 
quaternionic and non-quaternionic vector analysis. 
Prof. Tait, Prof. Willard Gibbs, and Dr. Heavi- 
side were among the disputants. Dr. Macfarlane 
agreed with none of these, but took a line of his 
own, which he has worked out with ingenuity in 
many later papers. Last year, for example, he 
read a short paper on the subject before the 
Mathematical Congress at Cambridge. It was, 
however, as the devoted secretary of the Associa- 
tion for the Study of Quaternions and Allied 
Systems of Mathematics that he found his chief 
opportunity. This association, which was started 
by Dr. Kimura, of Japan, is now a fairly strong 
