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Physiology and its Chemistry 
[January, 
relating to the discovery of cerebrin.* As a matter of 
history it is interesting to recal how preference was given 
by his contemporaries, among them his own friend Von 
Gorup-Besanez, to the work of Liebreich,t and how since 
that time Liebreich’s protogon has been proved to consist of 
a mixture of cerebrin and myelin,! while Muller’s cerebrin 
remains a definite individual. Space alone prevents our 
entering here into observations regarding the extent to which 
the action of baryta upon cerebrin may have misled Muller, 
for with that adtion he was not acquainted. In those pages 
of the Handbook devoted to Saliva we meet with the fol- 
lowing passage “When poured from one vessel to another,” 
says Dr. L. Brunton, “ it (saliva) is seen to be more or less 
viscid, in consequence of which it is generally filled with 
air-bubbles. If none are present they are readily produced 
by blowing into the liquid by a narrow glass tube, when it 
is seen they take a long time to subside.” And somewhat 
later, referring to methods of stimulating the secretion of 
saliva, he recommends one to “ colledt a considerable quan- 
tity, by filling the mouth with ether ;” and again, “ roll a 
pebble or a glass stopper in the mouth, and attempt to chew 
it.” Another matter to which we take exception in this part 
of the book is that, while Thudichum has worked more than 
any other chemist living on the biliary colouring-matters, 
his name does not occur in connection with this subjedt ; 
indeed the only mention of his name throughout the book 
consists in a bare reference to his treatise on the “ Pathology 
of the Urine.” Dr. Brunton gives Stadeler’s formulae for 
bilirubin (C i6 H i 8 N 2 0 3 ) and biliverdin (C i 6 H 20 N 2 0 5 ). These 
formulae had been withdrawn by Stadeler at the time when 
Dr. Brunton wrote, and he had substituted other formulae 
which were theoretically constructed on a perversion of 
Thudichum’s own results. The true formulae for these sub- 
stances are — for bilirubin C 9 H 9 N0 2 , for biliverdin || C 8 H 9 N0 2 . 
Kryptophanic acid, which was proved by Thudichum to 
constitute the normal free acid of human urine (C 5 H 9 N0 5 ), 
and whose compounds have been thoroughly worked out, 
is not even mentioned in the Handbook. On the other 
hand, indican (C i 6 H I2 N 2 0 2 ) is said to be ever present in 
urine. We have personally examined many different 
* Ann. Chem. Pharm., 105, 361 (1858). 
f Ibid, 134, 29. 
J Med. Off. Rep. Privy Council, New Series, No. III., 1874. 
|] See “ State of Animal Chemistry in Austria,” by J. L. W. Thudichum, 
M.D. Chemical News, April 13th and 21st, 1876 ; and Manual of Chemical 
Physiology. 
