History AND DEVELOPMENT 19 
are now concentrated in vacuo under a low degree of heat. to 
prevent discoloration or burning. | do not claim concentrating 
milk in a vacuum pan for such a purpose, my object being to 
exclude the air from the beginning of the process to the end, 
to prevent incipient decomposition. ‘This is important and I 
claim the discovery.” 
The claim, United States Patent No. 15,553, August 19. 
1856, is in the following words: 
“Producing concentrated sweet milk by evaporation in vacuo, 
substantially as set forth—the same having no sugar or other 
foreign matter mixed with it.” 
Since the introduction of the process of milk condensing, m- 
vented and patented by Borden, numerous modifications of the 
process, as well as entirely different processes, have been in- 
vented in this country and abroad. ‘The most characteristic 
among these are: condensation by refrigeration, by centrifugal 
force, by boiling under atmospheric pressure. by passing hot air 
over or through milk, ete. Most of these new processes have 
not proved commercially satisfactory, with the result that the 
principle of the process, originally invented by Gail Borden, 
and which consists of condensing the milk in vacuo to a semi- 
fluid liquid, is still made use of in the manufacture of the great 
bulk of condensed milk produced, both in this country and 
abroad. 
While the claim of the patent granted Gail Borden was 
that of “producing concentrated sweet milk by evaporation in 
vacuo without the admixture of sugar or other foreign mat- 
ter,” records show that Gail Borden manufactured sweetened 
condensed milk, sold under the famous Fagle Brand label as 
early as 1856. The first advertisement by Borden of unsweet- 
ened condensed milk was recorded in Leslie’s Weekly, May 
22, 1858. It reads as follows: 
“Borden's Condensed Milk. Prepared in Litchheld County, 
Conn., is the only milk ever concentrated without the admix- 
ture of sugar or some other substance and remaining easily 
soluble in water. It is simply Fresh Country Milk, from which 
the water is nearly all evaporated, and nothing added. The 
Committee of the Academy of Medicine recommend it as ‘an 
