104 LIFE OF BENJAMIN SILLIMAN. 



be evolved by the heat of a lamp applied to a glass retort. 

 Hare thought it necessary to use stone retorts with a fur- 

 nace-heat ; the retorts were purchased by me at a dollar 

 each, and, as they were usually broken in the experiment, 

 the research was rather costly ; but rny friend furnished 

 experience, and, as I was daily acquiring it, I was rewarded, 

 both for labor and expense, by the brilliant results of our 

 experiments. Hare's apparatus was ingenious, but unsafe 

 as regards the storage of the gases. Novice as I was, I 

 ventured to suggest to my more experienced friend that by 

 some accident or blunder the gases near neighbors as 

 they were in their contiguous apartments might become 

 mingled, when, on lighting them at the orifice, an explosion 

 would follow. I was afterwards informed, although not by 

 Hare, that this accident actually happened to him, although 

 with no other mischief than a copious shower-bath from the 

 expulsion of the water. Many years afterwards, Professor 

 Hitchcock at Amherst, from the same cause, met with an 

 explosion which gave him a great shock, and for a time 

 greatly impaired his hearing. 



After my return to New Haven, I contrived a mode of 

 separating these gases so effectually that they could not 

 become mixed. Eventually I employed separate gasom- 

 eters, one to contain the oxygen and the other the hydro- 

 gen, and during forty years that they were in use no acci- 

 dent ever happened. On this subject I may remark again 

 farther on. During the second course in Philadelphia 

 (winter of 1803-4) I commenced writing lectures on heat 

 and other general topics of chemistry, with reference to the 

 commencement of my labors of instruction in Yale College. 

 I enjoyed the important assistance of the lectures of the 

 distinguished Dr. Black of Edinburgh, then recently pub- 

 lished by his pupil and friend, Dr. Robison. This book 

 was to me a mine of riches. The first edition of Thomson's 

 Chemistry, in four volumes, had then just appeared, and I 

 took hold of it with avidity and with profit. 





