ae REPORT—1845, 
tion of the elements of water, included between the limits C,, Hs Og and C,, Hy, 0,4, 
as lignine, inuline, &c. &c. 
Order 1. Genus 2. Formula being that for amylon, minus a certain number of equi- 
valents of oxygen, and all being allied to fatty matters. 
Order 2. Genus 1. Products effected by contact with bodies in which the ultimate 
elements are in the act of assuming new arrangements. 
Order 2. Genus 2. Products effected by heat. (Pyrogenic bodies.) 
Order 2. Genus 3, Products effected by oxidizing agents, 
: Class II. Proreunocenic Bopits. 
Order 1. Results of organization. 
Order 2, Artificial products. 
Order 1. Genus 1. Variable in the quantity of inorganic matter they contain; as al- 
bumen and fibrine. 
Order 1. Genus 2. Variable in the quantity of oxygen which they contain, the carbon 
and nitrogen remaining constant; as the middle coat of arteries and mucus. 
Order 1. Genus 8. Bodies in which all the organic elements assume a new proportion 
to each other, but which may be considered as compounds of proteine and a non- 
nitrogenized body included in Class 1. Order 1. 
Order 2. Genus 1. Products resulting from the disturbance of the molecular equili- 
brium of proteine compounds when deprived of vitality, the action being much 
promoted by moderate increase of temperature and moisture. (Eremacasis of 
Liebig.) 
Order a Genus 2. Products effected by a high temperature. (Pyrogenic bodies.) 
Order 2. Genus 3. Results of the action of oxidizing agents; these are very nume- 
rous. 
The author believes that no difficulty will occur in referring any organic body to 
one or other of the above divisions, and proceeds to give, as an instance of the appli- 
cation of the system, the interpretation of the analysis of the food of the milch cow, 
On Gutta Percha, a nem variety of Caoutchouc. By Epwarp Sotty, F.R.S. 
Within the last two or three years, a very remarkable substance has been trans- 
mitted to this country from Sincapore under the name of Gutta Percha; it was first 
sent over by Dr. Montgomerie, who received the gold medal of the Society for the 
Encouragement of Arts, &c., for its introduction into this country as a new and hitherto 
unknown substance likely to be useful for several purposes in the arts. He was how- 
ever unable to ascertain the tree from which it is procured, or indeed any more of its 
history than that it is obtained in large quantities by cutting down the trees which 
yield it, and that it is employed by the natives to make the handles of knives and 
other tools, being preferred by them for this purpose even to buffalo’s horn. Mr. 
Solly described Gutta Percha as being a white or dirty pinkish-coloured solid, having 
little or no smell, insoluble in water and consequently tasteless, having a silky fibrous 
texture, and feeling smooth and almost greasy to the fingers; at the same time that 
it presents considerable resistance to any substance which is rubbed or drawn across 
it, thus enabling it to be grasped or held with great firmness in the hand. 
At temperatures below 50° it is hard, tough, and in thin pieces flexible, a good deal 
resembling horn in its physical characters. From 50° to 70° it becomes more flexible 
and slightly elastic, still however retaining its remarkable stiffness and toughness. 
When forcibly extended it shows very little power of contraction, requiring consider- 
able force to extend it, and retaining the form which has been given to it after the 
force which was applied is discontinued. At a temperature between 140° and 160° it 
becomes soft and remarkably plastic, its tenacity being at the same time greatly 
diminished. In this state two or more pieces may be joined together with the greatest 
facility (far greater than is the case with caoutchouc), and in a manner which may 
almost be compared to bees’-wax, inasmuch as whether the pieces are clean or dirty 
they unite on the slightest pressure and form a perfect joint. 
When in the soft and plastic state, Gutta Percha may be pressed or moulded into 
any required shape; as it cools it gradually re-acquires its former tough and rigid 
nature. The casts which are obtained in this manner from coins, medals, &c., are 
remarkably sharp and perfect. Gutta Percha at ordinary temperature is divided by 
