Report of the Consulting Chemist. 
285 
of the Society, and again in 1869, when 465 analyses were sent 
out from the lahoratory. Notwithstanding this steady increase 
in the three preceding years, as many as 580 analyses have been 
referred to me during the past year, being the unprecedented 
increase of 115 analyses over the number sent out in 1869. The 
appended summary shows that a large number of guanos and 
artificial manures of the class of superphosphates were examined 
in 1870, as well as an unusually large number of oilcakes. 
Comparatively few of the guanos were adulterated, but many 
were found damaged by sea-water and of inferior quality. On 
an average, the proportion of ammonia yielded by the guano 
analysed in 1870 little exceeded 14 per cent., and in several 
cases the proportion was less than 13 per cent. 
It is to be hoped that the supply of guano from the Guanape 
Islands will turn out to be of a superior quality than has been 
anticipated. 
I have recently made a number of analyses of Guanape guano 
for the Peruvian Government, and am glad to be able to report 
that nearly all the samples were much drier than those analysed 
in the preceding year. Although not equal in quality to the 
best Chincha Island guano of former years, the Guanape Island 
guanos recently analysed by me are about equal to the average 
quality of last year's importations of Peruvian guano. It remains 
to be seen whether Guanape guano, which no doubt will be sold 
as Peruvian, is uniform in character. 
By far the greater number of artificial manures — such as 
special Wheat, Oat, Barley, Potato, and Grass manures — are 
mixtures of dissolved bones or superphosphates with ammoniacal 
salts, common salt, dried blood, nitrate of soda, and other nitro- 
genous fertilising mateiials. These manures are, therefore, 
grouped together with superphosphates. As many as 152 
samples of superphosphates and similar manures were analvsed 
by me in 1870. 
Large sums of money are annually expended in the purchase 
of phosphatic manures, and as the quality of these manures 
varies exceedingly, and the actual price at which they are sold 
does not always correspond with the intrinsic value of the 
manure, it is highly desirable that purchasers of superphos- 
phate or dissolved bones should buy these manures of a quality 
guaranteed by analysis. The following analyses of two super- 
phosphates offered for sale in the same place, one at GZ. 3s. 
(cash) per ton, and the other at 4Z. 3.s., afford a good illustration 
of the lact that a considerable saving may often be effected if 
the composition of rival superphosphates is determined previous 
to purchase : — 
