100 Rivero and Boussingault 07i the Milk of the Cow-Tree. 
no precipitate, and makes it more liquid : this character indicates 
the total absence of catechu, since we have observed, that, in 
juices containing this ingredient, ammonia precipitates it ; and 
that the precipitate washed and dried, possesses the properties 
of elastic gum. When left to the contact of air, it is altered, 
and acquires an unpleasant smell, similar to that of sour milk ; 
a pellicle is formed at the surface, which, triturated with caustic 
potash, exhales ammonia. During this decomposition, carbonic 
acid is disengaged, and acetic acid is formed, which, very likely, 
combines with the ammonia. If some drops of an acid are add- 
ed to this milk, it may be exposed to the air, for a long time, 
without any alteration. Kept in a bottle, with a crystal stopper, 
it does not decompose, but becomes only thicker ; but, by add- 
ing a little water, it regains all its properties. In this manner, 
we preserve a small quantity of it we have brought from Mara- 
cay. Alcohol gives a slight precipitate ; fresh milk reddens blue 
paper; it boils at the temperature of 100° centigrade. On 
the fire it presents the same phenomena as cow’s milk ; a pellicle 
is formed on the surface, which prevents the expansion of aque- 
ous vapours : if the evaporation is carried on, for a long time, 
drops of oil are formed, which increase in proportion as the water 
evaporates, and terminate by forming an oily liquid ; in which 
swims a fibrous substance, which dries and contracts with the 
increase of the temperature of the oily liquor ; then it exhales 
a smell very similar to that of meat fried in oil. 
By the action of fire the vegetable milk is separated into two 
parts ; one fusible, on account of its greasy nature ; the other 
fibrous and infusible. If evaporation is not carried on too fast, 
and if the greasy matter is not made to boil, it may be obtained 
without any alteration, and possessing the following properties. 
This substance is yellowish- white, and translucent ; and has 
all the appearance of refined wax of Spain. It is solid at the 
common temperature, and does not yield to the pressure of the 
finger even at the maximum of temperature in Maracay (31° 
cent). It begins to melt at 40° cent. ; and when in complete 
fusion, the same thermometer indicates 60°. It is soluble in es- 
sential oil ; in turpentine it is also soluble, at a high temperature ; 
and, when cold, it separates in two parts, the interior with the 
