INVESTIGATIONS WITH RESPECT TO AQUA LAUROCERASI. 
603 
resulting from the rectification of gas-tar, might be obtained, and, at the same time, the 
slack itself might be converted into a useful fuel. 
There is also, in the Island of Trinidad, a vast deposit of bitumen, which has repeatedly 
been an object of passing interest on account of attempts to render it in some way use¬ 
ful. Unfortunately, most of those attempts have hitherto failed; but if liquid fuel 
should become an article in demand, I think there may be good days still in the future 
for Trinidad bitumen, for it has the peculiarity of yielding by distillation, about 30 per 
cent, of a thick, heavy oil, approximating very closely to the “ dead oil ” of the gas-tar 
refiner. This circumstance, which has hitherto been the disadvantage of the Trinidad 
bitumen, might then become its chief recommendation, and, according to all accounts, 
there is abundance of it, and the getting of it is not attended with difficulty. 
The relative cost of coal and oil is, to some extent, still an open question. If it should 
be found advantageous to use oil as fuel for steam vessels, it is probable that neither 
crude petroleum nor paraffin oil as obtained by distilling coal or shale would be the most 
suitable for the purpose, and that it would be advisable to separate from either of those 
materials the more volatile portions, which are applicable for burning in lamps. The 
less volatile portion, both of petroleum and of shale oil, amounting in the former to 
about 30 per cent., and in the latter to about 40 per cent., would be for several reasous 
best adapted for use as fuel. It is not so much in demand as the oil used for lamps, 
and being less volatile it could be stowed with greater safety. But I doubt much 
whether this oil could be shipped for less than £5 per ton. If that opinion is correct, 
according to the comparative estimate already made between coal and oil, the cost of 
the latter would be about three times as much as that of coal. That there may be cir¬ 
cumstances under which the advantages to be gained by the use of oil as fuel would 
altogether outweigh any considerations as to this, or even a greater rate of cost, it does 
not require any great penetration to perceive ; but it appears to me equally evident that 
if those advantages are to be attained only at such a cost, the use of oil as fuel for steam 
vessels must, in any case, be restricted to exceptional cases, in which cost is compara¬ 
tively a matter of secondary importance, and that it cannot be regarded as likely either 
to revolutionize steam navigation in general, or to call for a total reconstruction of our 
navy. 
At this point, however, the consideration of the subject reaches a stage where it is 
more the province of the merchant and of the naval engineer to deal with it, and to 
determine the balance between the greater efficacy of this material as fuel, and the 
greater cost which its application would involve. I therefore leave it here for those 
more competent than myself to discuss these points, with the hope that the attempt I 
have made to elucidate the subject, so far as I am able, may be found of some utility in 
its further development. 
I cannot, however, conclude this paper without taking the opportunity of expressing 
my opinion that the mode in which this subject has hitherto been dealt with, illustrates 
in a most striking manner, the want which is now somewhat vaguely felt of what is 
termed “technical education,” by which I understand a means, not merely of making 
those whose business is of a practical character better acquainted with the principles of 
science and the laws of nature than is generally the case in this country, but also of 
educating the cultivators of science in a knowledge of the requirements of art, and of 
the conditions under which science can be made serviceable to practice. If such a closer 
alliance between science and practice were achieved, I believe it would be found of 
mutual advantage, and then I apprehend we should soon cease to hear anything more of 
that fancied antagonism between the two which is the most effectual barrier to progress, 
and deserves only to be regarded as an indication of ignorance or bigotry. 
INVESTIGATIONS WITH RESPECT TO AQUA LAUROCERASI. 
BY J. BROEKER, 
APOTHECARY TO THE PORCES. 
This paper contains statements, from various authors and Pharmacopoeias, relating to 
laurel-water, and investigations by the writer himself. In the latter he proposed to an- 
