50 Years Ago

“Incorporation of radioactive amino-acids in the proteins of bull spermatozoa” — It is widely held that ribonucleic acid is directly involved in protein synthesis, and there have been several recent demonstrations of the necessity for the presence of ribonucleic acid during synthesis of proteins. In view of this, it seemed to be of interest to examine protein turnover in mature, ejaculated spermatozoa, which apparently contain at most only traces of ribonucleic acid... The absence of the acid from bull semen has been confirmed in the present investigation... It is possible that in this case deoxyribonucleic acid may be involved in the synthesis of proteins... The other possibility would be to regard protein synthesis in spermatozoa as an enzymatic process independent of nucleic acids.

From Nature 1 June 1957.

100 Years Ago

Mr. Walter Wellman, who proposes to make another attempt to reach the North Pole by means of his airship America, has left for Norway, on the way to Spitsbergen, where the balloon will be inflated. In the first week of July there will be trials of the airship until it is demonstrated that it is ready for the voyage... Mr. Wellman has given Reuter's representative the following particulars of his plans:— The airship has been made 18 feet longer and its lifting power increased by 3000 lb., giving a total lifting force of 19,500 lb. The balloon is 184 feet long and 52 feet in its greatest diameter, its cubic volume being 265,000 cubic feet. With the single exception of Count Zeppelin's airship, this is the largest ever built...The total radius of action is believed to be 2500 miles, or double the distance from the base to the Pole and back again. The balloon will not ascend more than 300 feet to 500 feet, and a guide-rope will trail over the surface of the earth.

From Nature 30 May 1907.