6 FUMIGATION METHODS 
invitation, Mr. Coquillett took his apparatus to the 
orchards of A. D. Bishop, and commenced a new series 
of tests. The ones giving the best results were the 
same as some of Mr. Coquillett’s earliest experiments, 
in which the gas was generated in a simple generator 
beneath the tent, according to the formula now gen- 
erally used. 
It was generally believed by Mr. Coquillett at this 
time that it was the actinic rays rather than the heat 
rays of the sun that injured the foliage. It had been 
previously noticed that trees were more injured during 
the middle of the day than at other times, and it 
was usually attributed to the heat. Working on his 
theory, Mr. Coquillett began experiments with a 
black tent, and confirmed his belief that it was the 
actinic and not the heat rays that caused the trouble. 
Naturally, night work in fumigation soon followed. 
It was on Mr. Bishop’s place where the first practical 
night fumigation was inaugurated. The success of 
these experiments has been far-reaching. The adop- 
tion of methods here perfected has been quite univer- 
sal. In practical results, the fumigation at night is 
satisfactory and regarded as essential to good fumiga- 
tion in citrous orchards. Mr. Bishop, in company 
with some neighbors, applied for a patent on the proc- 
ess, which was granted, even in the face of a strong 
protest from Mr. Coquillett and Dr. Riley to the Com- 
missioner of Patents. Later, however, the courts de- 
‘cided that the process was not patentable, and the 
‘controversy ended. 
The main interests centering around fumigation 
were confined mainly to California until 1893. In 
