TRANSACTIONS OF SECTION I. 977 
bodies have been recognised as existing, but it can now be said that it will probably 
be found that they play an important part as constituents of the animal economy, 
They are met with as bodies presenting all grades of complexity of composition, 
In some, of which salicin may be adduced as an example, only the three elements, 
carbon, hydrogen, and oxygen are present. In others, of which amygdalin is an 
example, the four elements, carbon, hydrogen, oxygen, and nitrogen, exist. In 
myronie acid, a glucoside obtainable from the seed of the black mustard, we have 
the four elements that have been named, with the addition of sulphur. ‘hese are 
bodies of comparatively simple composition, and from them advance can be made 
to the complex bodies forming the basis of living matter. Mucin, found not only 
in mucus, but forming also a constituent of connective tissue, was a short time ago 
shown by Landwehr to fall in the category of glucosides. In my ‘ Physiology of 
the Carbohydrates,’ published in 1894, p. 27 ct seq., I supplied evidence showing 
that proteid matter generally, alike of the animal and vegetable kingdoms of 
nature, is in constitution a glucoside. 
As mentioned in the work referred to, I was led to this discovery in the 
course of my quantitative examination of the various structures of the body for 
glycogen, ‘lhe process I had for many years adopted consisted of dissolving by 
boiling with potash, pouring into alcohol, collecting the precipitate, converting 
into glucose with sulphuric acid, and titrating with the copper test. I had been 
regarding the product derived from the structures as consisting of glycogen, but 
I subsequently learnt that it was influenced in quantity by duration of the 
exposure in contact with potash, and by the strength of the potash solution 
employed. 
If glycogen only had constituted the source of the product obtained, the cir- 
cumstances ought to have been otherwise. The treatment with potash should 
have produced no eflect beyond dissolving the associated nitrogenous matter and 
placing it in a position to be separable by the agency of the alcohol, and no 
difference in the amount of product obtained should have resulted from varying 
the strength of the alkali or the length of time of contact. The conclusion became 
inevitable that there must be something besides glycogen to give rise to the result, 
and the only feasible conclusion was that an amylose carbohydrate was derived 
from a cleavage of the proteid molecule. 
Having found that from a variety of proteids drawn from both animal and 
vegetable sources I could obtain carbohydrate, evidently derivable from a breaking- 
up of the proteid, and it is to be said in no insignificant amount, I took purified 
egg albumen as a material for the further study of the subject. 
Summarily, it may be stated, as the result of this study, that by the agency of 
potash an amylose carbohydrate, corresponding with Landwehr’s animal gum, is 
procurable, which is convertible by sulphuric acid into a body giving the various 
characteristic reactions of sugar. 
By the direct action of sulphuric acid sugar at once is yielded, and the same 
occurs as a result of pepsin digestion. 
Details are given in full upon these points in my work, to which I have already 
referred; and in my ‘ Epicriticism’ (Churchill, 1895) analytical evidence is sup- 
plied from the laboratory of Mr. Ling, affording conclusive proof that the osazone 
obtainable from the product is a sugar osazone. 
Since the publication of my results I have found that they are to the fullest 
extent corroborated by analytical experiments performed by the distinguished 
chemist Schiitzenberger upwards of twenty years ago. Schiitzenberger studied the 
products arising from the breaking-up of egg albumen by strong chemical agents, 
and his paper on the subject is contained in the ‘ Bull. de la Soc, Chim. de Paris,’ 
vol. xxiii. (1875), p. 161. 
Speaking of the products derived from the treatment with sulphuric acid, he 
mentions a non-azotised body which energetically reduced Fehling’s solution, was 
precipitable by the ammoniated acetate of lead solution, and which, in his own 
words, ‘ parait étre de Ja glucose ou un corps analogue.’ 
Again, after exposing egg albumen with baryta to 100°C. for 120 hours, he 
obtained a non-azotised body, insoluble in alcohol, precipitable by the ammoniated 
