Balata and the Balata Industry. 207 
plied from below. A process of drying balata milk in shallow trays by 
steam heat was, I think, carried out for some time in Trinidad by J. J. 
Day, formerly Professor of Chemistry in the Queen's College there.* 
I believe Professor Day found the process to be very successful, and 
only gave up the manufacture of the gum on account of scarcity of 
material — there being so few bullet-trees on the island. A parapraph in 
Ure's Dictionary of Arts, &c, shews that attempts have already been 
made in this colony to manufacture balata gum by other means. At page 
572, vol. 2., under the heading Substitutes for Gutta-percha it is stated 
that " Sir William Holmes forwarded to the Council of the Society 
" of Arts from Demerara some other specimens of gum termed 
" ' Balata' the produce of bullet -tree (Sapota Mulleri) which grows in 
" that colony, and which, he stated, possesses the property of gutta- 
" percha, and may be used as a substitute for it. Sir William 
" Holmes says in his communication : I was commissioner representing 
" the Colony of British Guiana, at the International Exhibition of 1862. 
" Among the varied contributions from the colony was a specimen from 
" the dried milk of the bullet-tree ; it weighed perhaps half a pound. 
" Amongst the numerous individuals who visited the Guiana Depart- 
" ment, was Mr. Charles Hancock, who is well known in the 
" gutta-percha trade. This gentleman was struck with the appear- 
" ance of the specimen, and obtained a portion for experiment. 
" He reported most favourably as to its utility and value, a result 
* The best method that I have experimented with is to drive off the 
water by means of steam at ioo° C. This drying is accomplished in 
large leaden trays fitted in boxes, a space of an inch and a half being 
allowed between the lead and the box. Steam from a boiler under 
ordinary atmospheric pressure is allowed to pass into the box and 
circulate around the leaden tray ; the gum is then poured into the tray 
and kept constantly stirred up by wooden stirrers so as to prevent a film 
forming at the surface. In the course of an hour and a half the mass 
will have become almost dry ; it is then removed from the leaden tray 
and exposed to the air for two or three days to become entirely dried 
and hard. Great care must be taken in all these processes that no 
vessel or article of iron or tin be employed in the preparation, as by its 
a6tion the colour of the substance is changed and becomes almost black 
owing to the presence ot tannin or tannic acid in the juice itself. To 
obviate this, all vessels or tools employed are made either of lead or 
copper. — J. J. Day, in Proceedings of the Trinidad Scientific Associa- 
tion. 
