ROBOT CHEMIST
robot chemist with an electric eye, radio brain and magnet hands functioned without human supervision in an improvised laboratory recently before members of the New York Electrical Society.
The automatic chemist performed several experiments. Its work was explained by William C. MacTavish, professor of chemistry at New York University, and was part of a program in which cold light was reproduced, a sample weighing a millionth of a gram analyzed, a photo-electric cell used to control analysis and new scientific apparatus demonstrated.
In his talk on "The Magic of Modern Chemistry," Professor MacTavish demonstrated the separation of para-hydrogen and ortho-hydrogen. In the micro-analysis of a millionth of a gram, Professor MacTavish exhibited in the micro-projector a ball of gold weighing one thousandth of a milligram (one twenty-eight millionth of an ounce), having a value of less than one ten-thousandth of a cent.
The robot chemist was the joint creation of Dr. H. M. Partridge and Professor Ralph H. Muller of the department of chemistry at New York University. In explaining what the automatic chemist can do, Professor MacTavish said:
"The ability of the automatic chemist to control chemical operations is due to its sensitivity to slight variations in color and light intensity. Its working parts are very simple. They consist of a standard light source, in this case an electric light, a photo-electric cell which detects differences in the amount of light impinging on it, a radio tube which amplifies the signal received from the photo-electric cell and which operates the relays controlling the automatic valves.
"Between the electric light and the photo-electric cell is placed a glass vessel holding an alkali that is to be neutralized. Above is a tube from which an acid passes, drop by drop, through an automatic valve, into the alkali. A small amount of chemical indicator added to the alkali maintains a red color in it until it is neutralized. When a sufficient amount of the acid has dropped into the alkali, the red color disappears, indicating complete neutralization.
"When the solution is colored red, an insufficient amount of lights gets through to the photo-electric cell. As the red color gradually diminishes, the amount of light passing through increases, and when the solution is entirely clear the light reaches a critical value which causes the photo-electric cell to pass a signal to the radio tube. This tube operates the relay which closes a valve and shuts off the supply of acid.
"Using a device of this sort to perform such operations around a laboratory will save a great deal of a chemist's time. Its electric eye is about 165 times as sensitive to differences in color as any human eye."
The fly landed with a thud on the center table.