120 
adhere, and in consequence of the almost unpossessed degree 
of patience required, and of the time consumed by nearly in- 
terminable failures.” Detailing the processes of Mr. Smith- 
son, three in number, and the success of that gentleman, he 
adopted a modification of Smithson’s third process, having 
recourse, as a support, to a portion of the mineral itself, which 
he designed to expose to the action of the flame. “ Instead, 
however, of taking upon the point of platinum wire a very 
minute portion of the paste made of the powdered mineral,’ 
according to Mr. Smithson’s method, he “formed a paste by 
mixing the powder with very thick gum-water and rubbing 
a little of it under the finger, formed a very acute cone, some- 
times nearly an inch in length, and generally about a twen- 
tieth of an inch in diameter at the base.” To the apex of 
such cones, the most minute particles would adhere under 
the strongest blast of the blowpipe, and being insulated by 
the destruction of continuity of the particles of the cone, the 
flame could be directed upon it with undiminished fervor. 
Experiments were made on a number of minerals, confirm- 
ing those of Mr. Smithson, and greatly extending the power 
of the blowpipe, and he was thus led to add to the three 
classes divided in relation to this instrument a fourth, namely; 
“such as are fusible, per se, in microscopical particles.” 
The attention of the inhabitants: near the shores of the 
great lakes of the North had often been arrested by the sud- 
den disappearance in the spring of the ice on the surface- 
The lakes would be covered with a continuous sheet of solid 
ice in the evening, and in the next morning all would have 
vanished. Wild speculations had been entertained as to the 
of this phenomenon previous to the investigation 
of the subject by General Totten, who presented. an article 
on the subject to the American Association for the Advance 
ment of Science at the Springfield meeting in 1859. 
