HIS WORK ON CHEMISTRY. 319 



made of his last regular assistant, Mr. Mason C. 

 Weld, one of the present editors of" The American 

 Agriculturist." Among the gentlemen who were 

 more or less associated with him as occasional as- 

 sistants are Mr. William Blake, Prof. T. Sterry Hunt, 

 Prof. Charles H. Porter, Prof. John P. Norton, Prof. 

 George J. Brush, and Prof. William H. Brewer, 

 names since distinguished in the annals of American 

 science. 



In 1830, Professor SilHman published, in two vol- 

 umes, his " Elements of Chemistry." This extended 

 work was mainly written in a little room connected 

 with his laboratory, to which he retired after taking 

 his tea, laboring at his task sometimes until near 

 midnight. He says of the work: 



In the preface to the first volume, I find the following 

 statement of my embarrassments. " If it does not excuse, 

 it may account for, some inadvertencies, when it is known 

 that an arduous and responsible work was written and 

 printed under the unremitting pressure of absorbing and 

 often conflicting duties. Life is flying fast away, while in 

 the hope of discharging more perfectly our duties to our 

 fellow-men, we wait in vain for continued seasons of leisure 

 and repose, in which we may refresh and brighten our fac- 

 ulties and perfect our knowledge. But after we are once 

 engaged in the full career of duty, such seasons never 

 come. Our powers and our time are placed in incessant 

 requisition, there is no discharge in our warfare, and we 

 must fight our battles, not in the circumstances and position 

 we would have chosen, but in those that are forced upon 



us by imperious necessity." Its reception by candid 



men was quite favorable. I received many expressions of 

 approbation ; and teachers of chemistry regarded it as a 



